FDA Label for Omeprazole/sodium Bicarbonate

1.1 Duodenal Ulcer

Omeprazole and sodium bicarbonate for oral suspension is indicated for short-term treatment of active duodenal ulcer. Most patients heal within four weeks. Some patients may require an additional four weeks of therapy. [See Clinical Studies ( 14.1)]

1.2 Gastric Ulcer

Omeprazole and sodium bicarbonate for oral suspension is indicated for short-term treatment (4-8 weeks) of active benign gastric ulcer. (See Clinical Studies ( 14.2)]

Symptomatic Gerd

Omeprazole and sodium bicarbonate for oral suspension is indicated for the treatment of heartburn and other symptoms associated with GERD. [See Clinical Studies ( 14.3)]

A placebo controlled study was conducted in Scandinavia to compare the efficacy of omeprazole 20 mg or 10 mg once daily for up to 4 weeks in the treatment of heartburn and other symptoms in GERD patients without erosive esophagitis. Results are shown in Table 11.

Erosive Esophagitis

Omeprazole and sodium bicarbonate is indicated for the short-term treatment (4-8 weeks) of erosive esophagitis which has been diagnosed by endoscopy. (See CLINICAL PHARMACOLOGY, Clinical Studies.)

The efficacy of omeprazole and sodium bicarbonate used for longer than 8 weeks in these patients has not been established. In the rare instance of a patient not responding to 8 weeks of treatment, it may be helpful to give up to an additional 4 weeks of treatment. If there is recurrence of erosive esophagitis or GERD symptoms (eg, heartburn), additional 4-8 week courses of omeprazole may be considered. [See Clinical Studies ( 14.3)]

In a U.S. multicenter double-blind placebo controlled study of 40 mg or 20 mg of omeprazole in patients with symptoms of GERD and endoscopically diagnosed erosive esophagitis of grade 2 or above, the percentage healing rates (per protocol) were as shown in Table 12.

In this study, the 40 mg dose was not superior to the 20 mg dose of omeprazole in the percentage healing rate. Other controlled clinical trials have also shown that omeprazole is effective in severe GERD. In comparisons with histamine H2-receptor antagonists in patients with erosive esophagitis, grade 2 or above, omeprazole in a dose of 20 mg was significantly more effective than the active controls. Complete daytime and nighttime heartburn relief ocurred significantly faster (p < 0.01) in patients treated with omeprazole than in those taking placebo or histamine H2-receptor antagonists.

In this and five other controlled GERD studies, significantly more patients taking 20 mg omeprazole (84%) reported complete relief of GERD symptoms than patients receiving placebo (12%).

1.4 Maintenance Of Healing Of Erosive Esophagitis

Omeprazole and sodium bicarbonate is indicated to maintain healing of erosive esophagitis. Controlled studies do not extend beyond 12 months. [See Clinical Studies ( 14.4)]

1.5 Reduction Of Risk Of Upper Gastrointestinal Bleeding In Critically Ill Patients

Omeprazole and sodium bicarbonate for oral suspension 40 mg/1680 mg is indicated for the reduction of risk of upper GI bleeding in critically ill patients. [See Clinical Studies, Reduction of Risk of Upper Gastrointestinal Bleeding in Critically Ill Patients ( 14.5)]

2 Dosage And Administration

Omeprazole and sodium bicarbonate is available for oral suspension in 20 mg and 40 mg strengths for adult use. Directions for use is summarized in Table 1. All recommended doses throughout the labeling are based upon omeprazole

Since both the 20 mg and 40 mg oral suspension packets contain the same amount of sodium bicarbonate (1680 mg), two packets of 20 mg are not equivalent to one packet of omeprazole and sodium bicarbonate 40 mg; therefore, two 20 mg packets of omeprazole and sodium bicarbonate should not be substituted for one packet of omeprazole and sodium bicarbonate 40 mg.

Omeprazole and sodium bicarbonate for oral suspension should be taken on an empty stomach at least one hour before to a meal.

For patients receiving continuous NG/OG tube feeding, enteral feeding should be suspended approximately 3 hours before and 1 hour after administration of omeprazole and sodium bicarbonate powder for oral suspension.

Special Populations

Hepatic Insufficiency

Consider dose reduction, particularly for maintenance of healing of erosive esophagitis. [See Clinical Pharmacology ( 12.3)]

Preparation and Administration of Suspension

Directions for use: Empty packet contents into a small cup containing 1-2 tablespoons of water. DO NOT USE OTHER LIQUIDS OR FOODS. Stir well and drink immediately. Refill cup with water and drink.

If omeprazole and sodium bicarbonate is to be administered through a nasogastric or orogastric tube, the suspension should be constituted with approximately 20 mL of water. DO NOT USE OTHER LIQUIDS OR FOODS. Stir well and administer immediately. An appropriately-sized syringe should be used to instill the suspension in the tube. The suspension should be washed through the tube with 20 mL of water.

3 Dosage Forms And Strengths

Omeprazole and sodium bicarbonate for oral suspension is a white, flavored powder packaged in unit-dose packets. Each packet contains either 20 mg or 40 mg omeprazole and 1680 mg sodium bicarbonate.

4 Contraindications

Omeprazole and sodium bicarbonate for oral suspension is contraindicated in patients with known hypersensitivity to any components of the formulation. Hypersensitivity reactions may include anaphylaxis, anaphylactic shock, angioedema, bronchospasm, interstitial nephritis, and urticaria.

5.1 Concomitant Gastric Malignancy

Symptomatic response to therapy with omeprazole does not preclude the presence of gastric malignancy.

5.2 Atrophic Gastritis

Atrophic gastritis has been noted occasionally in gastric corpus biopsies from patients treated long-term with omeprazole.

5.3 Buffer Content

Each packet of omeprazole and sodium bicarbonate for oral suspension contains 1680 mg (20 mEq) of sodium bicarbonate (equivalent to 460 mg of Na+).

The sodium content of omeprazole and sodium bicarbonate products should be taken into consideration when administering to patients on a sodium restricted diet.

Because omeprazole products contain sodium bicarbonate, they should be used with caution in patients with Bartter’s syndrome, hypokalemia, hypocalcemia, and problems with acid-base balance. Long-term administration of bicarbonate with calcium or milk can cause milk-alkali syndrome.

Chronic use of sodium bicarbonate may lead to systemic alkalosis and increased sodium intake can produce edema and weight increase.

5.4 Clostridium Difficile Associated Diarrhea

Published observational studies suggest that PPI therapy like omeprazole and sodium bicarbonate for oral suspension may be associated with an increased risk of Clostridium difficile associated diarrhea, especially in hospitalized patients. This diagnosis should be considered for diarrhea that does not improve. [see Adverse Reactions (6.2)]

Patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated.

5.5 Interaction With Clopidogrel

Avoid concomitant use of omeprazole and sodium bicarbonate for oral suspension with clopidogrel. Clopidogrel is a prodrug. Inhibition of platelet aggregation by clopidogrel is entirely due to an active metabolite. The metabolism of clopidogrel to its active metabolite can be impaired by use with concomitant medications, such as omeprazole, that interfere with CYP2C19 activity. Concomitant use of clopidogrel with 80 mg omeprazole reduces the pharmacological activity of clopidogrel, even when administered 12 hours apart. When using omeprazole and sodium bicarbonate for oral suspension, consider alternative anti-platelet therapy [see Drug Interactions (7.5) and Pharmacokinetics (12.3)].

5.6 Bone Fracture

Several published observational studies suggest that proton pump inhibitor (PPI) therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist, or spine. The risk of fracture was increased in patients who received high-dose, defined as multiple daily doses, and long-term PPI therapy (a year or longer). Patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated. Patients at risk for osteoporosis-related fractures should be managed according to the established treatment guidelines. [See Dosage and Administration ( 2) and Adverse Reactions (6.2)]

5.7 Hypomagnesemia

Hypomagnesemia, symptomatic and asymptomatic, has been reported rarely in patients treated with PPIs for at least three months, in most cases after a year of therapy. Serious adverse events include tetany, arrhythmias, and seizures. In most patients, treatment of hypomagnesemia required magnesium replacement and discontinuation of the PPI.

For patients expected to be on prolonged treatment or who take PPIs with medications such as digoxin or drugs that may cause hypomagnesemia (e.g., diuretics), health care professionals may consider monitoring magnesium levels prior to initiation of PPI treatment and periodically. (See Adverse Reactions ( 6.2)]

5.8 Concomitant Use Of Omeprazole And Sodium Bicarbonate For Oral Suspension With St. John's Wort Or Rifampin

Drugs which induce CYP2C19 OR CYP34A (such as St. John’s Wort or rifampin) can substantially decrease omeprazole concentrations. [see Drug Interactions (7.2)]. Avoid concomitant use of omeprazole and sodium bicarbonate for oral suspension with St. John’s Wort or rifampin.

5.9 Interactions With Investigations For Neuroendocrine Tumors

Serum chromogranin A (CgA) levels increase secondary to drug-induced decreases in gastric acidity. The increased CgA level may cause false positive results in diagnostic investigations for neuroendocrine tumors. Providers should temporarily stop omeprazole treatment before assessing CgA levels and consider repeating the test if initial CgA levels are high. If serial tests are performed (e.g. for monitoring), the same commercial laboratory should be used for testing, as reference ranges between tests may vary. [see Pharmacodynamics (12.2)]

5.10 Concomitant Use Of Omeprazole And Sodium Bicarbonate For Oral Suspension With Methotrexate

Literature suggests that concomitant use of PPIs with methotrexate (primarily at high dose; see methotrexate prescribing information) may elevate and prolong serum levels of methotrexate and/or its metabolite, possibly leading to methotrexate toxicities. In high-dose methotrexate administration, a temporary withdrawal of the PPI may be considered in some patients. (See Adverse Drug Interactions ( 7.7)

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

In the U.S. clinical trial population of 465 patients, the adverse reactions summarized in Table 2 were reported to occur in 1% or more of patients on therapy with omeprazole. Numbers in parentheses indicate percentages of the adverse reactions considered by investigators as possibly, probably or definitely related to the drug.

Table 3 summarizes the adverse reactions that occurred in 1% or more of omeprazole-treated patients from international double-blind, and open-label clinical trials in which 2,631 patients and subjects received omeprazole.

A controlled clinical trial was conducted in 359 critically ill patients, comparing omeprazole and sodium bicarbonate 40 mg/1680 mg suspension once daily to I.V. cimetidine 1200 mg/day for up to 14 days. The incidence and total number of AEs experienced by ≥ 3% of patients in either group are presented in Table 13 by body system and preferred term.

6.2 Postmarketing Experience

The following adverse reactions have been identified during post-approval use of omeprazole. Because these reactions are voluntarily reported from a population of uncertain size, it is not always possible to reliably estimate their actual frequency or establish a causal relationship to drug exposure.

Body as a Whole

Hypersensitivity reactions, including anaphylaxis, anaphylactic shock, angioedema, bronchospasm, interstitial nephritis, urticaria (see also Skin below), fever, pain, fatigue, malaise

Cardiovascular

Chest pain or angina, tachycardia, bradycardia, palpitation, elevated blood pressure, and peripheral edema.

Gastrointestinal

Pancreatitis (some fatal), anorexia, irritable colon, flatulence, fecal discoloration, esophageal candidiasis, mucosal atrophy of the tongue, dry mouth, stomatitis and abdominal swelling. During treatment with omeprazole, gastric fundic gland polyps have been noted rarely. These polyps are benign and appear to be reversible when treatment is discontinued. Gastroduodenal carcinoids have been reported in patients with Zollinger-Ellison syndrome on long-term treatment with omperazole. This finding is believed to be associated with such tumors.

Hepatic

Mild and, rarely, marked elevations of liver function tests (ALT (SGPT), AST (SGOT), y-glutamyl transpeptidase, alkaline phosphatase, and bilirubin (jaundice)]. In rare instances, overt liver disease has occurred, including hepatocellular, cholestatic, or mixed hepatitis, liver necrosis (some fatal), hepatic failure (some fatal), and hepatic encephalopathy

Infections and Infestations: Clostridium difficile associated diarrhea.

Metabolic and Nutritional Disorders

Hyponatremia, hypoglycemia, hypomagnesemia, and weight gain.

Musculoskeletal

Muscle cramps, myalgia, muscle weakness, joint pain, bone fracture, and leg pain.

Nervous System/Psychiatric

Psychic disturbances including depression, agitation, aggression, hallucinations, confusion, insomnia, nervousness, tremors, apathy, somnolence, anxiety, dream abnormalities; vertigo; paresthesia; and hemifacial dysesthesia.

Respiratory

Epistaxis, pharyngeal pain.

Skin

Severe generalized skin reactions including toxic epidermal necrolysis (TEN; some fatal), Stevens-Johnson syndrome, and erythema multiforme (some severe); purpura and/or petechiae (some with rechallenge); skin inflammation, urticaria, angioedema, pruritus, photosensitivity, alopecia, dry skin, and hyperhidrosis.

Special Senses

Tinnitus, taste perversion.

Ocular

Blurred vision, ocular irritation, dry eye syndrome, optic atrophy, anterior ischemic optic neuropathy, optic neuritis and double vision.

Urogenital

Interstitial nephritis (some with positive rechallenge), urinary tract infection, microscopic pyuria, urinary frequency, elevated serum creatinine, proteinuria, hematuria, glycosuria, testicular pain, and gynecomastia.

Hematologic

Rare instances of pancytopenia, agrunulocytosis (some fatal), thrombocytopenia, neutropenia, leucopenia, anemia, leucocytosis, and hemolytic anemia have been reported.

The instance of clinical adverse experiences in patients greater than 65 years of age was similar to that in patients 65 years of age or less.

Additional adverse reactions that could be caused by sodium bicarbonate include metabolic alkalosis, seizures, and tetany.

7.1 Drugs For Which Gastric Ph Can Affect Bioavailability

Because of its inhibition of gastric acid secretion, it is theoretically possible that omeprazole may interfere with absorption of drugs where gastric pH is an important determinant of their bioavailability (e.g., ketoconazole, ampicillin esters, and iron salts). In the clinical efficacy trials, antacids were used concomitantly with the administration of omeprazole.

7.2 Drugs Metabolized By Cytrochrom P450 (Cyp)

Omeprazole can prolong the elimination of diazepam, warfarin and phenytoin, drugs that are metabolized by oxidation in the liver. There have been reports of increased INR and prothrombin time in patients receiving proton pump inhibitors, including omeprazole, and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death. Patients treated with proton pump inhibitors and warfarin may need to be monitored for increases in INR and prothrombin time.

Although in normal subjects no interaction with theophylline or propranolol was found, there have been clinical reports of interaction with other drugs metabolized via the cytochrome P-450 system (eg, cyclosporine, disulfiram, benzodiazepines). Patients should be monitored to determine if it is necessary to adjust the dosage of these drugs when taken concomitantly with omeprazole and sodium bicarbonate.

Concomitant administration of omeprazole and voriconazole (a combined inhibitor of CYP2C19 and CYP3A4) resulted in more than doubling of the omeprazole exposure. Dose adjustment of omeprazole is nto normally required. When voriconazole (400 mg every 12 hours for one day, then 200 mg for 6 days) was given with omeprazole (40 mg once daily for 7 days) to healthy subjects, it significantly increased the steady-state Cmax of AUC0-24 of omeprazole, an average of 2 times (90% CI: 1.8, 2.6) and 4 times (90% CI: 3.3, 4.4) respectively as compared to when omeprazole was given without voriconazole.

Drugs known to induce CYP2C19 or CYP3A4 (such as rifampin) may lead to decreased omperazole serum levels. In a cross-over study in 12 healthy male subjects, St, John's wort (300 mg three times daily for 14 days), an inducer of CYP3A4, decreased the systemic exposure of omeprazole in CYP2C19 poor metabolisers (Cmax and AUC decreased by 49.6% and 43.9%, respectively). Avoid concomitant use of St. John's Wort or rifampin with omeprazole.

7.3 Antiretroviral Agents

Concomitant administration of atazanavir and proton pump inhibitors is not recommended. Co-administration of atazanavir with proton pump inhibitors is expected to substantially decrease atazanavir plasma concentrations and thereby reduce its therapeutic effect.

Omeprazole has been reported to interact with some antiretroviral drugs. The clinical importance and the mechanisms behind these interactions are not always known. Increased gastric pH during omeprazole treatment may change the absorption of the antiretroviral drug. Other possible interaction mechanisms are via CYP2C19. For some antiretroviral drugs, such as atazanavir and nelfinavir, decreased serum levels have been reported when given together with omeprazole. Following multiple doses of nelfinavir (1250 mg, twice daily), and omeprazole (40 mg, daily), AUC was decreased by 36% and 92%, C max by 37% and 89% and Cmin by 39% and 75% respectively for nelfinavir and M8. Following multiple doses of atazanavir (400 mg, daily) and omeprazole (40 mg, daily, 2 hours before atazanavir), AUC was decreased by 94%, Cmax by 96%, and Cmin by 95%. Concomitant administration with omeprazole and drugs such as atazanavir and nelfinavir is therefore not recommended.

Increased concentration of saquinavir

For other antiretroviral drugs, such as saquinavir, elevated serum levels have been reported with an increase in AUC by 82%, in Cmax by 75% and in Cmin by 106% following multiple dosing of saquinavir/ritonavir (1000/100 mg) twice daily for 15 days with omeprazole 40 mg daily co-administered days 11 to 15. Dose reduction of saquinavir should be considered from the safety perspective for individual patients. There are also some antiretroviral drugs of which unchanged serum levels have been reported when given with omeprazole.

7.4 Combination Therapy With Clarithromycin

Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions due to drug interaction [see Warnings and Precautions in prescribing information for clarithromycin]. Because of these drug interactions, clarithromycin is contraindicated for co-administration with certain drugs [see Contraindication in prescribing information for clarithromycin].

7.5 Clopidogrel

Omeprazole is an inhibitor of CYP2C19 enzyme. Clopidogrel is metabolized to its active metabolite in part by CYP2C19. Concomitant use of omeprazole 80 mg results in reduced plasma concentrations of the active metabolite of clopidogrel and a reduction in platelet inhibition Avoid concomitant administration of omeprazole and sodium bicarbonate for oral suspension with clopidogrel. When using omeprazole and sodium bicarbonate for oral suspension consider use of alternative anti-platelet therapy [see Pharmacokinetics (12.3)].

7.6 Tacrolimus

Concomitant administration of omeprazole and tacrolimus may increase the serum levels of tacrolimus.

7.7 Interactions With Investigations Of Neuroendocrine Tumors

Drug-induced decrease in gastric acidity results in enterochromaffin-like cell hyperplasia and increased Chromogranin A levels which may interfere with investigations for neuroendocrine tumors. [see Clinical Pharmacology (12)].

7.8 Methotrexate

Case reports, published population pharmacokinetic studies, and retrospective analyses suggest that concomitant administration of PPIs and methotrexate (primarily at high dose, see methotrexate prescribing information) may elevate and prolong serum levels of methotrexate and/or its metabolite hydroxymethotrexate. However, no formal drug interaction studies of methotrexate with PPIs have been conducted. (See Warnings and Precautions ( 5.7).

Pregnancy Category C

There are no adequate and well-controlled studies on the use of omeprazole in pregnant women. The vast majority of reported experience with omeprazole during human pregnancy is first trimester exposure and the duration of use is rarely specified, eg, intermittent vs. chronic. An expert review of published data on experiences with omeprazole use during pregnancy by TERIS – the Teratogen Information System – concluded that therapeutic doses during pregnancy are unlikely to pose a substantial teratogenic risk (the quantity and quality of data were assessed as fair). ¹

Three epidemiological studies compared the frequency of congenital abnormalities among infants born to women who used omeprazole during pregnancy to the frequency of abnormalities among infants of women exposed to H2-receptor antagonists or other controls. A population-based prospective cohort epidemiological study from the Swedish Medical Birth Registry, covering approximately 99% of pregnancies, reported on 955 infants (824 exposed during the first trimester with 39 of these exposed beyond first trimester, and 131 exposed after the first trimester) whose mothers used omeprazole during pregnancy. ² In utero exposure to omeprazole was not associated with increased risk of any malformation (odds ratio 0.82, 95% CI 0.50-1.34), low birth weight or low Apgar score. The number of infants born with ventricular septal defects and the number of stillborn infants was slightly higher in the omeprazole exposed infants than the expected number in the normal population. The author concluded that both effects may be random.

A retrospective cohort study reported on 689 pregnant women exposed to either H2-blockers or omeprazole in the first trimester (134 exposed to omeprazole) ^.3 The overall malformation rate was 4.4% (95% CI 3.6-5.3) and the malformation rate for first trimester exposure to omeprazole was 3.6% (95% CI 1.5-8.1). The relative risk of malformations associated with first trimester exposure to omeprazole compared with nonexposed women was 0.9 (95% CI 0.3-2.2). The study could effectively rule out a relative risk greater than 2.5 for all malformations. Rates of preterm delivery or growth retardation did not differ between the groups.

A controlled prospective observational study followed 113 women exposed to omeprazole during pregnancy (89% first trimester exposures) ⁴. The reported rates of major congenital malformations was 4% for the omeprazole group, 2% for controls exposed to nonteratogens, and 2.8% in disease-paired controls (background incidence of major malformations 1-5%). Rates of spontaneous and elective abortions, preterm deliveries, gestational age at delivery, and mean birth weight did not differ between the groups. The sample size in this study has 80% power to detect a 5-fold increase in the rate of major malformation.

Several studies have reported no apparent adverse short term effects on the infant when single dose oral or intravenous omeprazole was administered to over 200 pregnant women as premedication for cesarean section under general anesthesia.

Reproduction studies conducted with omeprazole in rats at oral doses up to 28 times the human dose of 40 mg/day (based on body surface area) and in rabbits at doses up to 28 times the human dose (based on body surface area) did not show any evidence of terogenicity. In pregnant rabbits, omeprazole at doses about 2.8 to 28 times the human dose of 40mg/day, (based on body surface area) produced dose-related increases in embryo-lethality, fetal resorptions, and pregnancy loss. In rats treated with omeprazole at doses about 2.8 to 28 times the human dose (based on body surface area), dose-related embryo/fetal toxicity and postnatal developmental toxicity occurred in offspring. [See Animal Toxicology and/or Pharmacology ( 13.2)].

There are no adequate and well-controlled studies in pregnant women. Because animal studies and studies in humans cannot rule out the possibility of harm, omeprazole and sodium bicarbonate should be used during pregnancy only if the potential benefit to pregnant women justifies the potential risk to the fetus.

8.3 Nursing Mothers

Omeprazole concentrations have been measured in breast milk of a woman following oral administration of 20 mg. The peak concentration of omeprazole in breast milk was less than 7% of the peak serum concentration. The concentration will correspond to 0.004 mg of omeprazole in 200 mL of milk. Because omeprazole is excreted in human milk, because of the potential for serious adverse reactions in nursing infants from omeprazole, and because of the potential for tumorigenicity shown for omeprazole in rat carcinogenicity studies, a decision should be taken to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. In addition, sodium bicarbonate should be used with caution in nursing mothers.

8.4 Pediatric Use

Safety and effectiveness of omeprazole and sodium bicarbonate have not been established in pediatric patients less than 18 years of age.

8.5 Geriatric Use

Omeprazole was administered to over 2000 elderly individuals (≥ 65 years of age) in clinical trials in the U.S. and Europe. There were no differences in safety and effectiveness between the elderly and younger subjects. Other reported clinical experience has not identified differences in response between the elderly and younger subjects, but greater sensitivity of some older individuals cannot be ruled out.

Pharmacokinetic studies with buffered omeprazole have shown the elimination rate was somewhat decreased in the elderly and bioavailability was increased. The plasma clearance of omeprazole was 250 mL/min (about half that of young subjects). The plasma half-life averaged one hour, about the same as that in nonelderly, healthy subjects taking omeprazole and sodium bicarbonate. However, no dosage adjustment is necessary in the elderly. (See CLINICAL PHARMACOLOGY ( 12.3)]

8.6 Hepatic Impairment

Consider dose reduction, particularly for maintenance of healing erosive esophagitis. [See Clinical Pharmacology ( 12.3)]

8.7 Renal Impairment

No dose reduction is necessary. [See Clinical Pharmacology ( 12.3)]

8.8 Asian Population

Recommended dose reduction, particularly for maintenance of healing of erosive esophagitis. [See Clinical Pharmacology ( 12.3)]

10 Overdosage

Reports have been received of overdosage with omeprazole in humans. Doses ranged up to 2400 mg (120 times the usual recommended clinical dose). Manifestations were variable, but included confusion, drowsiness, blurred vision, tachycardia, nausea, vomiting, diaphoresis, flushing, headache, dry mouth, and other adverse reactions similar to those seen in normal clinical experience. (See ADVERSE REACTIONS.( 6)]. Symptoms were transient, and no serious clinical outcome has been reported when omeprazole was taken alone. No specific antidote for omeprazole overdosage is known. Omeprazole is extensively protein bound and is, therefore, not readily dialyzable. In the event of overdosage, treatment should be symptomatic and supportive.

As with the management of any overdose, the possibility of multiple drug ingestion should be considered. For current information on treatment of any drug overdose, a certified Regional Poison Control Center should be contacted. Telephone numbers are listed in the Physicians’ Desk Reference (PDR) or local telephone book.

Single oral doses of omeprazole at 1350, 1339, and 1200 mg/kg were lethal to mice, rats, and dogs, respectively. Animals given these doses showed sedation, ptosis, tremors, convulsions, and decreased activity, body temperature, and respiratory rate and increased depth of respiration.

In addition, a sodium bicarbonate overdose may cause hypocalcemia, hypokalemia, hypernatremia, and seizures.

11 Description

Omeprazole and sodium bicarbonate for oral suspension is a combination of omeprazole, a proton-pump inhibitor, and sodium bicarbonate, an antacid. Omeprazole is a substituted benzimidazole, 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2‑pyridinyl)methyl]sulfinyl]-1 H-benzimidazole, a racemic mixture of two enantiomers that inhibits gastric acid secretion. Its structural formula is C₁₇H₁₉N₃O₃S, with a molecular weight of 345.42. The structural formula is:

This is the structured formula - omeprazole and sodium bicarbonate for oral suspens 1

Omeprazole is a white to off-white crystalline powder which melts with decomposition at about 155°C. It is a weak base, freely soluble in ethanol and methanol, and slightly soluble in acetone and isopropanol and very slightly soluble in water. The stability of omeprazole is a function of pH; it is rapidly degraded in acid media, but has acceptable stability under alkaline conditions.

Omeprazole and sodium bicarbonate is supplied as unit dose packets for oral suspension. Packets for oral suspension contain 40 mg or 20 mg of omeprazole and 1680 mg of sodium bicarbonate with the following excipients: xylitol, xanthan gum, sucralose powder, sodium bicarbonate, peach powder, sucrose and peppermint flavor.

12 Clinical Pharmacology

Omeprazole is acid labile and thus rapidly degraded by gastric acid. Omeprazole/sodium bicarbonate for oral suspension is an immediate-release formulation that contains sodium bicarbonate which raises the gastric pH and thus protects omeprazole from acid degradation.

12.1 Mechanism Of Action Section

Omeprazole belongs to a class of antisecretory compounds, the substituted benzimidazoles, that do not exhibit anticholinergic or H2 histamine antagonistic properties, but that suppress gastric acid secretion by specific inhibition of the H+/K+ ATPase enzyme system at the secretory surface of the gastric parietal cell. Because this enzyme system is regarded as the acid (proton) pump within the gastric mucosa, omeprazole has been characterized as a gastric acid-pump inhibitor, in that it blocks the final step of acid production. This effect is dose related and leads to inhibition of both basal and stimulated acid secretion irrespective of the stimulus. Animal studies indicate that after rapid disappearance from plasma, omeprazole can be found within the gastric muscosa for a day or more.

Omeprazole is acid labile and thus rapidly degraded by gastric acid. Omeprazole and sodium bicarbonate for oral suspension is immediate-release formulation that contains sodium bicarbonate which raises the gastric pH and thus protects from acid degradation.

12.2 Pharmacodynamics

Antisecretory Activity

Results from a PJ/PD study of the antisecretory effect of repeated once-daily dosing of 40 mg and 20 mg of omeprazole and sodium bicarbonate for oral suspension in healthy subjects are shown in Table 6 below.

Note: Values represent medians. All parameters were measured over a 24-hour period.*p<0.05 20 mg vs. 40 mg

Results from a separate PK/PD study of antisecretory effect on repeated once-daily dosing of 40 mg/1100 mg and 20 mg/1100 mg of omeprazole and sodium bicarbonate capsules in healthy subjects show similar effects in general on the above three PD parameters as those for omeprazole and sodium bicarbonate 40 mg/1680 mg and 20 mg/1680 mg powder for oral suspension, respectively.

The antisecretory effect lasts longer than would be expected from the very short (1 hour) plasma half-life, apparently due to irreversible binding to the parietal H+/K+ ATPase enzyme.

Enterochromaffin-like (ECL) Cell Effects

In 24-month carcinogenicity studies in rats, a dose-related significant increase in gastric carcinoid tumors and ECL cell hyperplasia was observed in both male and female animals. [See Nonclinical Toxicology (13.1)]. Carcinoid tumors have also been observed in rats subjected to fundectomy or long-term treatment with other proton pump inhibitors or high doses of H2-receptor antagonists. Human gastric biopsy specimens have been obtained from more than 3000 patients treated with omeprazole in long-term clinical trials. The incidence of ECL cell carcinoids, dysplasia, or neoplasia has been found in these patients. These studies are of insufficient duration and size to rule out the possible influence of long-term administration of omeprazole on the development of any premalignant or malignant conditions.

Serum Gastrin Effects

In studies involving more than 200 patients, serum gastrin levels increased during the first 1 to 2 weeks of once-daily dosing administration of therapeutic doses of omeprazole in parallel with inhibition of acid secretion. No further increase in serum gastrin occurred with continued treatment. In comparison with histamine H2-receptor antagonists, the median increases produced by 20 mg doses of omeprazole were higher (1.3 to 3.6 fold vs. 1.1 to 1.8 fold increase). Gastrin values returned to pretreatment levels, usually within 1 to 2 weeks after discontinuation of therapy.

Increased gastrin causes enterchromaffin-like cell hyperplasia and increased serum Chromogranin-like cell hyperplasia and increased serum Chromogranin A (CgA) levels. The increased CgA levels may cause false positive results in diagnostic investigations for neuroendocrine tumors.

Other Effects

Systemic effects of omeprazole in the CNS, cardiovascular and respiratory systems have not been found to date. Omeprazole, given in oral doses of 30 or 40 mg for 2 to 4 weeks, had no effect on thyroid function, carbohydrate metabolism, or circulating levels of parathyroid hormone, cortisol, estradiol, testosterone, prolactin, cholecystokinin or secretin.

No effect on gastric emptying of the solid and liquid components of a test meal was demonstrated after a single dose of omeprazole 90 mg. In healthy subjects, a single I.V. dose of omeprazole (0.35 mg/kg) had no effect on intrinsic factor secretion. No systematic dose-dependent effect has been observed on basal or stimulated pepsin output in humans. However, when intragastric pH is maintained at 4.0 or above, basal pepsin output is low, and pepsin activity is decreased.

As do other agents that elevate intragastric pH, omeprazole administered for 14 days in healthy subjects produced a significant increase in the intragastric concentrations of viable bacteria. The pattern of the bacterial species was unchanged from that commonly found in saliva. All changes resolved within three days of stopping treatment.

The course of Barrett’s esophagus in 106 patients was evaluated in a U.S. double-blind controlled study of omeprazole 40 mg b.i.d. for 12 months followed by 20 mg b.i.d. for 12 months or ranitidine 300 mg b.i.d. for 24 months. No clinically significant impact on Barrett’s, mucosa by antisecretory therapy was observed. Although neosquamous epithelium developed during antisecretory therapy, complete elimination of Barrett’s mucosa was not achieved. No significant difference was observed between treatment groups in development of dysplasia in Barrett’s mucosa and no patient developed esophageal carcinoma during treatment. No significant differences between treatment groups were observed in development of ECL cell hyperplasia, corpus atrophic gastritis, corpus intestinal metaplasia, or colon polyps exceeding 3 mm in diameter.

Absorption

In separate in vivo bioavailability studies, when omeprazole and sodium bicarbonate for oral suspension is administered on an empty stomach 1 hour prior to a meal, the absorption of omeprazole is rapid, with mean peak plasma levels (% CV) of omeprazole being 1954 ng/mL (33%) and 1526 ng/mL (49%), respectively, and time to peak of approximately 30 minutes (range 10-90 min) after a single-dose or repeated-dose administration. Absolute bioavailability of omeprazole and sodium bicarbonate for oral suspension (compared to I.V. administration) is about 30-40% at doses of 20 – 40 mg, due in large part to presystemic metabolism.

When omeprazole and sodium bicarbonate for oral suspension 40 mg/1680 mg was administered in a two-dose loading regimen, the omeprazole AUC(0-inf) (ng.hr/mL) was 1665 after Dose 1 and 3356 after Dose 2, while T _max was approximately 30 minutes for both Dose 1 and Dose 2.

Following single or repeated once daily dosing, peak plasma concentrations of omeprazole from omeprazole and sodium bicarbonate are approximately proportional from 20 to 40 mg doses, but a greater than linear mean AUC (three-fold increase) is observed when doubling the dose to 40 mg. The bioavailability of omeprazole from omeprazole and sodium bicarbonate increases upon repeated administration.

When omeprazole and sodium bicarbonate is administered 1 hour after a meal, the omeprazole AUC is reduced by approximately 24% relative to administration 1 hour prior to a meal.

Distribution

Omeprazole is bound to plasma proteins. Protein binding is approximately 95%.

Metabolism

Following single-dose oral administration of omeprazole, the majority of the dose (about 77%) is eliminated in urine as at least six metabolites. Two metabolites have been identified as hydroxyomeprazole and the corresponding carboxylic acid. The remainder of the dose was recoverable in feces. This implies a significant biliary excretion of the metabolites of omeprazole. Three metabolites have been identified in plasma – the sulfide and sulfone derivatives of omeprazole, and hydroxyomeprazole. These metabolites have very little or no antisecretory activity.

Excretion

Following single-dose oral administration of omeprazole, little if any, unchanged drug is excreted in urine. The mean plasma omeprazole half-life in healthy subjects is approximately 1 hour (range 0.4 to 3.2 hours) and the total body clearance is 500-600 mL/min.

Concomitant Use with Clopidogrel

In a crossover clinical study, 72 healthy subjects were administered clopidogrel (300 mg loading dose followed by 75 mg per day) alone with omeprazole (80 mg at the same time as clopidogrel) for 5 days. The exposure to the active metabolite of clopidogrel was decreased by 46% (Day 1) and 42% (Day 5) when clopidogrel and omeprazole were administered together.

Results from another crossover study in healthy subjects showed a similar pharmacokinetic interaction between clopidogrel (300 mg loading dose/75 mg daily maintenance dose) and omeprazole 80 mg daily when coadministered for 30 days. Exposure to the active metabolite of clopidogrel was reduced by 41% to 46% over this time period.

In another study, 72 healthy subjects were given the same dose of clopidogrel and 80 mg omeprazole but the drugs were administered 12 hours apart; the results were similar, indicating that administering clopidogrel at omeprazole at different times does not prevent their interaction.

Special Populations

Geriatric

The elimination rate of omeprazole was somewhat decreased in the elderly, and bioavailability was increased. Omeprazole was 76% bioavailable when a single 40-mg oral dose of omeprazole (buffered solution) was administered to healthy elderly subjects, versus 58% in young subjects given the same dose. Nearly 70% of the dose was recovered in urine as metabolites of omeprazole and no unchanged drug was detected. The plasma clearance of omeprazole was 250 mL/min (about half that of young subjects) and its plasma half-life averaged one hour, similar to that of young healthy subjects.

Pediatric

The pharmacokinetics of omeprazole and sodium bicarbonate have not been studied in patients <18 years of age.

Gender

There are no known differences in the absorption or excretion of omeprazole between males and females.

Hepatic Insufficiency

In patients with chronic hepatic disease, the bioavailability of omeprazole from a buffered solution increased to approximately 100% compared to an I.V. dose, reflecting decreased first-pass effect, and the mean plasma half-life of the drug increased to nearly 3 hours compared to the mean half-life of 1 hour in normal subjects. Plasma clearance averaged 70 mL/min, compared to a value of 500-600 mL/min in normal subjects.

Renal Insufficiency

In patients with chronic renal impairment, whose creatinine clearance ranged between 10 and 62 mL/min/1.73 m 2, the disposition of omeprazole from a buffered solution was very similar to that in healthy subjects, although there was a slight increase in bioavailability. Because urinary excretion is a primary route of excretion of omeprazole metabolites, their elimination slowed in proportion to the decreased creatinine clearance.

Asian Population

In pharmacokinetic studies of single 20 mg omeprazole doses, an increase in AUC of approximately four-fold was noted in Asian subjects compared to Caucasians. Dose adjustment, particularly where maintenance of healing of erosive esophagitis is indicated, for Asian subjects should be considered.

13.1 Carcinogenesis And Mutagenesis And Impairment Of Fertility

In two 24-month carcinogenicity studies in rats, omeprazole at daily doses of 1.7, 3.4, 13.8, 44.0 and 140.8 mg/kg/day (approximately 0.5 to 28.5 times the human dose of 40 mg/day, based on body surface area) produced gastric ECL cell carcinoids in a dose-related manner in both male and female rats; the incidence of this effect was markedly higher in female rats, which had higher blood levels of omeprazole. Gastric carcinoids seldom occur in the untreated rat. In addition, ECL cell hyperplasia was present in all treated groups of both sexes. In one of these studies, female rats were treated with 13.8 mg omeprazole/kg/day (approximately 2.8 times the human dose of 40 mg/day, based on body surface area) for one year, then followed for an additional year without the drug. No carcinoids were seen in these rats. An increased incidence of treatment-related ECL cell hyperplasia was observed at the end of one year (94% treated vs 10% controls). By the second year the difference between treated and control rats was much smaller (46% vs 26%) but still showed more hyperplasia in the treated group. Gastric adenocarcinoma was seen in one rat (2%). No similar tumor was seen in male or female rats treated for two years. For this strain of rat no similar tumor has been noted historically, but a finding involving only one tumor is difficult to interpret. In a 52-week toxicity study in Sprague-Dawley rats, brain astrocytomas were found in a small number of males that received omeprazole at dose levels of 0.4, 2, and 16 mg/kg/day (about 0.1 to 3.3 times the human dose of 40 mg/day, based on body surface area). No astrocytomas were observed in female rats in this study. In a 2-year carcinogenicity study in Sprague-Dawley rats, no astrocytomas were found in males and females at the high dose of 140.8 mg/kg/day (about 28.5 times the human dose of 40 mg/day, based on body surface area). A 78-week mouse carcinogenicity study of omeprazole did not show increased tumor occurrence, but the study was not conclusive. A 26-week p53 (+/-) transgenic mouse carcinogenicity study was not positive.

Omeprazole was positive for clastogenic effects in an in vitro human lymphocyte chromosomal aberration assay, in one of two in vivo mouse micronucleus tests, and in an in vivo bone marrow cell chromosomal aberration assay. Omeprazole was negative in the in vitro Ames Test, an in vitro mouse lymphoma cell forward mutation assay and an in vivo rat liver DNA damage assay.

In 24-month carcinogenicity studies in rats, a dose-related significant increase in gastric carcinoid tumors and ECL cell hyperplasia was observed in both male and female animals [See Warnings and Precautions (5)]. Carcinoid tumors have also been observed in rats subjected to fundectomy or long-term treatment with other proton pump inhibitors or high doses of H ₂-receptor antagonists.

Omeprazole at oral doses up to 138 mg/kg/day (about 28 times the human dose of 40 mg/day, based on body surface area) was found to have no effect on the fertility and general reproductive performance in rats.

13.2 Animal Pharmacology And/Or Toxicology Section

Reproductive Toxicology Studies

Reproduction studies conducted in pregnant rats at omeprazole doses up to 138 mg/kg/day (about 28 times the human dose of 40 mg/day, based on body surface area) and in pregnant rabbits at doses up to 69 mg/kg/day (about 28 times the human dose of 40 mg/day, based on body surface area) did not disclose any evidence for a teratogenic potential of omeprazole.

In rabbits, omeprazole in a dose range of 6.9 to 69 mg/kg/day (about 2.8 to 28 times the human dose of 40 mg/day, based on body surface area) produced dose-related increases in embryo-lethality, fetal resorptions and pregnancy disruptions. In rats, dose-related embryo/fetal toxicity and postnatal developmental toxicity were observed in offspring resulting from parents treated with omeprazole at 13.8 to 138.0 mg/kg/day (about 2.8 to 28 times the human dose of 40 mg/day, based on body surface area).

14.1 Duodenal Ulcer Disease

Active Duodenal Ulcer – In a multicenter, double-blind, placebo controlled study of 147 patients with endoscopically documented duodenal ulcer, the percentage of patients healed (per protocol) at 2 and 4 weeks was significantly higher with omeprazole 20 mg once a day than with placebo (p ≤ 0.01). (See Table 7.)

Complete daytime and nighttime pain relief occurred significantly faster (p ≤ 0.01) in patients treated with omeprazole 20 mg than in patients treated with placebo. At the end of the study, significantly more patients who had received omeprazole had complete relief of daytime pain (p ≤ 0.05) and nighttime pain (p ≤ 0.01).

In a multicenter, double-blind study of 293 patients with endoscopically documented duodenal ulcer, the percentage of patients healed (per protocol) at 4 weeks was significantly higher with omeprazole 20 mg once a day than with ranitidine 150 mg b.i.d. (p < 0.01). (See Table 7)

Healing occurred significantly faster in patients treated with omeprazole than in those treated with ranitidine 150 mg b.i.d. (p < 0.01).

In a foreign multinational randomized, double-blind study of 105 patients with endoscopically documented duodenal ulcer, 40 mg and 20 mg of omeprazole were compared to 150 mg b.i.d. of ranitidine at 2, 4 and 8 weeks.

At 2 and 4 weeks both doses of omeprazole were statistically superior (per protocol) to ranitidine, but 40 mg was not superior to 20 mg of omeprazole, and at 8 weeks there was no significant difference between any of the active drugs. (See Table 8)

14.2 Gastric Ulcer

In a U.S. multicenter, double-blind study of omeprazole 40 mg once a day, 20 mg once a day, and placebo in 520 patients with endoscopically diagnosed gastric ulcer, the following results were obtained. (See Table 9)

Table 9: Treatment of Gastric Ulcer % of Patients Healed (All Patients Treated)

For the stratified groups of patients with ulcer size less than or equal to 1 cm, no difference in healing rates between 40 mg and 20 mg was detected at either 4 or 8 weeks. For patients with ulcer size greater than 1 cm, 40 mg was significantly more effective than 20 mg at 8 weeks.

In a foreign, multinational, double-blind study of 602 patients with endoscopically diagnosed gastric ulcer, omeprazole 40 mg once a day, 20 mg once a day, and ranitidine 150 mg twice a day were evaluated. (See Table 10.)

14.4 Long Term Maintenance Treatment Of Erosive Esophagitis

In a U.S. double-blind, randomized, multicenter, placebo controlled study, two dose regimens of omeprazole were studied in patients with endoscopically confirmed healed esophagitis. Results to determine maintenance of healing of erosive esophagitis are shown in Table 13.

In an international multicenter double-blind study, omeprazole 20 mg daily and 10 mg daily were compared to ranitidine 150 mg twice daily in patients with endoscopically confirmed healed esophagitis. Table 15 provides the results of this study for maintenance of healing of erosive esophagitis.

In patients who initially had grades 3 or 4 erosive esophagitis, for maintenance after healing 20 mg daily of omeprazole was effective, while 10 mg did not demonstrate effectiveness.

14.5 Reduction Of Risk Of Upper Gastrointestinal Bleeding In Critically Ill Patients

A double-blind, multicenter, randomized, non-inferiority clinical trial was conducted to compare Omeprazole and sodium bicarbonate for oral suspension 40 mg/1680 mg and I.V. cimetidine for the reduction of risk of upper gastrointestinal (GI) bleeding in critically ill patients (mean APACHE II score = 23.7). The primary endpoint was significant upper GI bleeding defined as bright red blood which did not clear after adjustment of the nasogastric tube and a 5 to 10 minute lavage, or persistent Gastroccult® positive coffee grounds for 8 consecutive hours which did not clear with 100 cc lavage. Omeprazole/sodium bicarbonate oral suspension 40 mg/1680 mg (two doses administered 6 to 8 hours apart on the first day via orogastric or nasogastric tube, followed by 40 mg q.d. thereafter) was compared to continuous I.V. cimetidine (300 mg bolus, and 50 to 100 mg/hr continuously thereafter) for up to 14 days (mean = 6.8 days). A total of 359 patients were studied, age range 16 to 91 (mean = 56 yrs), 58.5% were males, and 64% were Caucasians. The results of the study showed that Omeprazole and sodium bicarbonate was non-inferior to I.V. cimetidine, 10/181(5.5%) patients in the cimetidine group vs. 7/178 (3.9%) patients in the Omeprazole and sodium bicarbonate group experienced clinically significant upper GI bleeding.

15 References

• 1.Friedman JM and Polifka JE. Omeprazole. In: Teratogenic Effects of Drugs. A Resource for Clinicians (TERIS). 2nd ed. Baltimore, MD: The Johns Hopkins University Press 2000; p. 516.
• 2.Kallen BAJ. Use of omeprazole during pregnancy – no hazard demonstrated in 955 infants exposed during pregnancy. Eur Obstet Gynecol Reprod Biol 2001; 96(1):63-8.
• 3.Ruigomez A, Rodriguez LUG, Cattaruzzi C, et al. Use of cimetidine, omeprazole, and ranitidine in pregnant women and pregnancy outcomes. Am J Epidemiol 1999; 150:476-81.
• 4.Lalkin A, Loebstein, Addis A, et al. The safety of omeprazole during pregnancy: a multicenter prospective controlled study. Am J Obstet Gynecol 1998; 179:727-30.

16 How Supplied/Storage And Handling

Omeprazole and sodium bicarbonate for oral suspension is a white to off white, granular powder packaged in individual dose packets. Each packet contains either 20 mg or 40 mg omeprazole and 1680 mg sodium bicarbonate.

NDC 49884-268-11 Cartons of 30: 20 mg/1680 mg unit dose packets

NDC 49884-269-11Cartons of 30: 40 mg/1680 mg unit dose packets

Store at 25°C (77°F); excursions permitted to 15 - 30°C (59 - 86°F). [See USP Controlled Room Temperature].

Keep this medication out of the hands of children. Keep container tightly closed. Protect from light and moisture.

17 Patient Counseling Information

See FDA-Approved Medication Guide.

Instruct patients that omeprazole and sodium bicarbonate should be taken on an empty stomach at least one hour prior to a meal. [See Dosage and Administration ( 2)]

Instruct patients in Directions for Use as follows:

For Oral Suspension: Empty packet contents into a small cup containing 1-2 tablespoons of water. DO NOT USE OTHER LIQUIDS OR FOODS. Stir well and drink immediately. Refill cup with water and drink.

Omeprazole and sodium bicarbonate is available either as 40 mg or 20 mg single-dose packets for oral suspension with 1680 mg sodium bicarbonate.

Patients should be instructed not to substitute omeprazole and sodium bicarbonate for oral suspension for other omeprazole and sodium bicarbonate dosage forms because different dosage forms contain different amounts of sodium bicarbonate and magnesium hydroxide. [See Dosage and Administration ( 2)]

Patients should be advised that since both the 20 mg and 40 mg oral suspension packets contain the same amount of sodium bicarbonate (1680 mg), two packets of 20 mg are not equivalent to one packet of omeprazole and sodium bicarbonate 40 mg; therefore, two 20 mg packets of omeprazole and sodium bicarbonate should not be substituted for one packet of omeprazole and sodium bicarbonate 40 mg. Conversely ½ of a 40 mg packet should not be substituted for one 20 mg packet. [See Dosage and Administration (2)]

Patients should be advised that this drug is not approved for patients less than 18 years of age. [See Pediatric Use ( 8.4)]

Patients on a sodium restricted diet or patients at risk of developing congestive heart failure (CHF) should be informed of the sodium content of omeprazole and sodium bicarbonate for oral suspension (460 mg per packet). Patients should be informed that chronic use of sodium bicarbonate may cause problems and increased sodium intake can cause swelling and weight gain. If this occurs, they should contact their healthcare provider. [See Warnings and Precautions ( 5.3]

Patients should be informed that the most frequent adverse reactions associated with omeprazole and sodium bicarbonate include headache, abdominal pain, nausea, diarrhea, vomiting and flatulence. [See Adverse Reactions ( 6)]

Pregnant women should be advised that a harmful effect of omeprazole and sodium bicarbonate on the fetus can not be ruled out and that the drug should be used with caution during pregnancy. [See Pregnancy ( 8.1)]

Patients should be advised to use this drug with caution if they are regularly taking calcium supplements. [See Warnings and Precautions ( 5.4)]

Advise patients to immediately report and seek care for diarrhea that does not improve. This may be a sign of Clostridium difficile associated diarrhea (see Warnings and Precautions (5.4)].

Advise patients to immediately report and seek care for any cardiovascular or neurological symptoms including palpitations, dizziness, seizures and tetany as these may be signs of hypomagnesemia. (see WARNINGS AND PRECAUTIONS (5.7)].

Manufactured by:

PAR PHARMACEUTICAL

Chestnut Ridge, NY 10977

Revised: 06/2016

Fda-Approved Medication Guide

Omeprazole and Sodium Bicarbonate for Oral Suspension

Read this Medication Guide before you start taking omeprazole and sodium bicarbonate and each time you get a refill. There may be new information. This leaflet does not take the place of talking to your doctor about your medical condition or treatment.

What is the most important information I should know about Omeprazole and Sodium Bicarbonate for Oral Suspension?

Omeprazole and Sodium Bicarbonate for Oral Suspension may help with your acid-related symptoms, but you could still have serious stomach problems. Talk with your doctor.

Omeprazole and Sodium Bicarbonate for Oral Suspension can cause serious side effects, including:

• Omeprazole and Sodium Bicarbontate for oral suspension contains sodium bicarbonate. Tell your doctor if you are on a sodium restricted diet or if you have Bartter’s Syndrome (a rare kidney disorder).

Tell your doctor right away if you have confusion, shaking hands, dizziness, muscle twitching, nausea, vomiting, and numbness or tingling in the face, arms, or legs.

• Diarrhea. Omeprazole and sodium bicarbonate for oral suspension may increase your risk of getting severe diarrhea. This diarrhea may be caused by an infection (Clostridium difficile) in your intestines.

Call your doctor right away if you have watery stool, stomach pain, and fever that does not go away.

• Bone fractures. People who take multiple daily doses of Proton pump inhibitor medicines for a long period of time (a year or longer) may have an increased risk of fractures of the hip, wrist or spine. You should take omeprazole and sodium bicarbonate for oral suspension exactly as prescribed, at the lowest dose possible for your treatment and for the shortest time needed. Talk to your doctor about your risk of bone fracture if you take omeprazole and sodium bicarbonate for oral suspension..

Omeprazole and sodium bicarbonate for oral suspension can have other serious side effects. See “What are the possible side effects of Omeprazole and Sodium Bicarbonate for Oral Suspension?”

What is Omeprazole and Sodium Bicarbonate for Oral Suspension?

Omeprazole and sodium bicarbonate for oral suspension is a prescription medicine called a proton pump inhibitor (PPI). Omeprazole and sodium bicarbonate for oral suspension reduces the amount of acid in your stomach.

Omeprazole and sodium bicarbonate for oral suspension is used in adults for:

• for 4 weeks to heal ulcers in the first part of the small bowel (duodenal ulcers). Your doctor may prescribe another 4 weeks of omeprazole and sodium bicarbonate for oral suspension..

• for up to 8 weeks for healing stomach ulcers

• for up to 4 weeks to treat heartburn and other symptoms that happen with gastroesophageal reflux disease (GERD).

GERD happens when acid from the stomach backs up into the tube (esophagus) that connects your mouth to your stomach. This may cause a burning feeling in your chest or throat, sour taste, or burping.

• for up to 8 weeks to heal acid-related damage to the lining of the esophagus (called erosive esophagitis or EE)

• to maintain healing of the esophagus. It is not known if omeprazole and sodium bicarbonate for oral suspension is safe and effective if used longer than 12 months (1 year).

• to lower the risk of stomach bleeding in critically ill people(40 mg Oral Suspension only)

It is not known if omeprazole and sodium bicarbonate for oral suspension is safe and effective in children less than 18 years of age.

Who should not take Omeprazole and Sodium Bicarbonate for Oral Suspension?

Do not take omeprazole and sodium bicarbonate for oral suspension if you:

• are allergic to omeprazole or any of the other ingredients in omeprazole and sodium bicarbonate for oral suspension. See the end of this Medication Guide for a complete list of ingredients in omeprazole and sodium bicarbonate for oral suspension.

• are allergic to any other proton pump inhibitor (PPI) medicine.

What should I tell my doctor before I take Omeprazole and Sodium Bicarbonate for Oral Suspension?

Before you take Omeprazole and Sodium Bicarbonate for Oral Suspension, tell your doctor if you:

• have been told that you have low magnesium, calcium, or potassium levels in your blood.

• have liver problems

• have heart failure

• have Bartter’s syndrome (a rare kidney disorder)

• have any allergies

• have any other medical conditions

• are pregnant or plan to become pregnant. It is not known if omeprazole and sodium bicarbonate for oral suspension can harm your unborn baby.

• are breastfeeding or plan to breastfeed. Omeprazole and sodium bicarbonate can pass into your breast milk and may harm your baby. You and your doctor should decide if you will take omeprazole and sodium bicarbonate for oral suspension or breastfeed. You should not do both. Talk with your doctor about the best way to feed your baby if you take omeprazole and sodium bicarbonate for oral suspension.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins and herbal supplements. Omeprazole and sodium bicarbonate for oral suspension may affect how other medicines work, and other medicines may affect how omeprazole and sodium bicarbonate for oral suspension works.

Especially tell your doctor if you take:

• diazepam (Valium®)

• warfarin (Coumadin® Jantoven)

• phenytoin (Dilantin®)

• cyclosporine (Gengraf, Neoral, Sandimmune)

• disulfiram (Antabuse®)

• a benzodiazepine medicine

• ketoconazole (Nizoral®)

• an antibiotic that contains ampicillin

• products that contain iron

• digoxin (Lanoxin®)

• voriconazole (Vfend®)

• atazanavir (Reyataz®)

• nelfinavir (Viracept®)

• tacrolimus (Prograf®)

• saquinavir (Fortovase®)

• clarithromycin (Biaxin®, Biaxin XL)

• clopidogrel (Plavix®)

• St. John’s Wort (Hypericum perforatum)

• rifampin (Rifater, Rifamate, Rimactane, Rifadin)

• methotrexate

Ask your doctor or pharmacist for a list of these medicines, if you are not sure.

Know the medicines that you take. Keep a list of them to show your doctor and pharmacist when you get a new medicine.

How should I take Omeprazole and Sodium Bicarbonate for Oral Suspension?

• Take omeprazole and sodium bicarbonate for oral suspension exactly as prescribed by your doctor.

• Do not change your dose or stop taking omeprazole and sodium bicarbonate for oral suspension without talking to your doctor. Take omeprazole and sodium bicarbonate for oral suspension on an empty stomach at least one hour before a meal.

• Empty the contents of a packet of omeprazole and sodium bicarbonate for oral suspension into a small cup containing 1 to 2 tablespoons of water. Do not use other liquids or foods. Stir well and drink immediately. Refill cup with water and drink.

• If you miss a dose of omeprazole and sodium bicarbonate for oral suspension, take it as soon as you remember. If it is almost time for your next dose, do not take the missed dose. Take the next dose at your regular time. Do not take two doses to make up for a missed dose.

• Do not substitute two 20 mg packets for one 40 mg packet of omeprazole and sodium bicarbonate for oral suspension because you will receive twice the amount of sodium bicarbonate. Talk to your doctor if you have questions.

• If you take too much omeprazole and sodium bicarbonate for oral suspension, call your doctor or Poison Control Center right away, or go to the nearest hospital emergency room.

• Your doctor may prescribe antibiotic medicines with omeprazole and sodium bicarbonate for oral suspension to help treat a stomach infection and heal stomach- area (duodenal) ulcers that are caused by bacteria called H. pylori. Make sure you read the patient information that comes with an antibiotic before you start taking it.

• See the “Instructions for Use” at the end of this Medication Guide for instructions on how to mix and give omeprazole and sodium bicarbonate for oral suspension through a nasogastric tube or orogastric tube.

What are the possible side effects of Omeprazole and Sodium Bicarbonate for Oral Suspension?

Omeprazole and Sodium Bicarbonate for Oral Suspension may cause serious side effects, including:

•  • See “What is the most important information I should know about Omeprazole and Sodium Bicarbonate for Oral Suspension?”

• Chronic (lasting a long time) inflammation of the stomach lining (Atrophic Gastritis). Taking omeprazole and sodium bicarbonate for oral suspension for a long period of time may increase the risk of inflammation to your stomach lining. You may or may not have symptoms. Tell your doctor if you have stomach pain, nausea, vomiting, or weight loss.

• Low magnesium levels in your body. This problem can be serious. Low magnesium can happen in some people who take a proton pump inhibitor medicine for at least 3 months. If low magnesium levels happen, it is usually after a year of treatment. You may or may not have symptoms of low magnesium.

Tell your doctor right away if you develop any of these symptoms:

• seizures

• dizziness

• abnormal or fast heartbeat

• jitteriness

• jerking movements or shaking (tremors)

• muscle weakness

• spasms of the hands and feet

• cramps or muscle aches

• spasm of the voice box

Your doctor may check the level of magnesium in your body before you start taking omeprazole and sodium bicarbonate for oral suspension, or during treatment, if you will be taking omeprazole and sodium bicarbonate for oral suspension for a long period of time.

The most common side effects with omeprazole and sodium bicarbonate for oral suspension include:

• headache

• abdominal pain

• nausea

• diarrhea

• vomiting

• gas

Other side effects:

• Serious allergic reactions. Tell your doctor if you get any of the following symptoms with omeprazole and sodium bicarbonate for oral suspension.

• rash

• face swelling

• throat tightness

• difficulty breathing

Your doctor may stop omeprazole and sodium bicarbonate for oral suspension if these symptoms happen.

Using omeprazole and sodium bicarbonate for oral suspension for a long time may cause problems such as swelling and weight gain. Tell your doctor if this happens.

If you are on a low-sodium diet or at risk of developing congestive heart failure (CHF), you and your doctor should decide if you will take omeprazole and sodium bicarbonate for oral suspension.

Tell your doctor if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of omeprazole and sodium bicarbonate for oral suspension. For more information, ask your doctor or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

How should I store Omeprazole and Sodium Bicarbonate for Oral Suspension?

• Store omeprazole and sodium, bicarbonate for oral suspension in a dry place at 25°C (77°F); excursions permitted to 15 -30°C (59 -86°F). [See USP Controlled Room Temperature].

• Keep omeprazole and sodium bicarbonate for oral suspension in a dry place and out of the light.

Keep Omeprazole and Sodium Bicarbonate for Oral Suspension and all medicines out of the reach of children.

General information about Omeprazole and Sodium Bicarbonate for Oral Suspension

Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Do not use omeprazole and sodium bicarbonate for oral suspension for any condition for which it was not prescribed by your doctor. Do not give omeprazole and sodium bicarbonate for oral suspension to other people, even if they have the same symptoms as you. It may harm them.

This Medication Guide summarizes the most important information about omeprazole and sodium bicarbonate for oral suspension. If you would like more information, talk to your doctor. You can also ask your doctor or pharmacist for information about omeprazole and sodium bicarbonate for oral suspension that is written for healthcare professionals.

For more information, go to www.parpharm.com or 1-800-828-9393.

What are the ingredients in Omeprazole and Sodium Bicarbonate for Oral Suspension?

Active ingredients: omeprazole and sodium bicarbonate

Inactive ingredients of omeprazole and sodium bicarbonate for oral suspension: xylitol, xanthan gum, sucralose powder, peach powder, sucrose and peppermint flavor.

Instructions for Use

For instructions on taking omeprazole and sodium bicarbonate for oral suspension by mouth, see “ How should I take Omeprazole and Sodium Bicarbonate for Oral Suspension?”

Giving Omeprazole and Sodium Bicarbonate for Oral Suspension through a nasogastric tube (NG tube) or gastric tube:

• Add 20 mL of water to a catheter tipped syringe and then add the contents of a packet as prescribed by your doctor. Use only a catheter tipped syringe to give omeprazole and sodium bicarbonate for oral suspension through a NG tube or orogastric tube.

• Shake the syringe to dissolve the powder.

• Give the medicine through the NG or orogastric tube into the stomach right away.

• Refill the syringe with an equal amount of water.

• Shake and flush any remaining contents from the NG tube or orogastric tube into the stomach.

This Medication Guide has been approved by the U.S. Food and Drug Administration.

For prescription only

Manufactured by:

PAR PHARMACEUTICAL

Chestnut Ridge, NY 10977

Revised: 06/2016