Associated with Discontinuation of Treatment
In 3-week clinical trials in adults and elderly patients (>65 years), 3.5% (7/201) patients receiving AMBIEN CR 6.25 or 12.5 mg discontinued treatment due to an adverse reaction as compared to 0.9% (2/216) of patients on placebo. The reaction most commonly associated with discontinuation in patients treated with AMBIEN CR was somnolence (1%).
In a 6-month study in adult patients (18–64 years of age), 8.5% (57/669) of patients receiving AMBIEN CR 12.5 mg as compared to 4.6% on placebo (16/349) discontinued treatment due to an adverse reaction. Reactions most commonly associated with discontinuation of AMBIEN CR included anxiety (anxiety, restlessness or agitation) reported in 1.5% (10/669) of patients as compared to 0.3% (1/349) of patients on placebo, and depression (depression, major depression or depressed mood) reported in 1.5% (10/669) of patients as compared to 0.3% (1/349) of patients on placebo.
Data from a clinical study in which selective serotonin reuptake inhibitor (SSRI)-treated patients were given zolpidem revealed that four of the seven discontinuations during double-blind treatment with zolpidem (n=95) were associated with impaired concentration, continuing or aggravated depression, and manic reaction; one patient treated with placebo (n=97) was discontinued after an attempted suicide.
Most Commonly Observed Adverse Reactions in Controlled Trials
During treatment with AMBIEN CR in adults and elderly at daily doses of 12.5 mg and 6.25 mg, respectively, each for three weeks, the most commonly observed adverse reactions associated with the use of AMBIEN CR were headache, next-day somnolence, and dizziness.
In the 6-month trial evaluating AMBIEN CR 12.5 mg, the adverse reaction profile was consistent with that reported in short-term trials, except for a higher incidence of anxiety (6.3% for AMBIEN CR versus 2.6% for placebo).
Adverse Reactions Observed at an Incidence of ≥1% in Controlled Trials
The following tables enumerate treatment-emergent adverse reactions frequencies that were observed at an incidence equal to 1% or greater among patients with insomnia who received AMBIEN CR in placebo-controlled trials. Events reported by investigators were classified utilizing the MedDRA dictionary for the purpose of establishing event frequencies. The prescriber should be aware that these figures cannot be used to predict the incidence of side effects in the course of usual medical practice, in which patient characteristics and other factors differ from those that prevailed in these clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigators involving related drug products and uses, since each group of drug trials is conducted under a different set of conditions. However, the cited figures provide the physician with a basis for estimating the relative contribution of drug and nondrug factors to the incidence of side effects in the population studied.
The following tables were derived from results of two placebo-controlled efficacy trials involving AMBIEN CR. These trials involved patients with primary insomnia who were treated for 3 weeks with AMBIEN CR at doses of 12.5 mg (Table 1) or 6.25 mg (Table 2), respectively. The tables include only adverse reactions occurring at an incidence of at least 1% for AMBIEN CR patients and with an incidence greater than that seen in the placebo patients.
Table 1: Incidences of Treatment-Emergent Adverse Reactions in a 3-Week Placebo-Controlled Clinical Trial in Adults (percentage of patients reporting)Body System
Adverse Reaction
Reactions reported by at least 1% of patients treated with AMBIEN CR and at greater frequency than in the placebo group. | AMBIEN CR
12.5 mg
| Placebo |
|---|
| (N=102) | (N=110) |
|---|
| Infections and infestations | |
| Influenza | 3 | 0 |
| Gastroenteritis | 1 | 0 |
| Labyrinthitis | 1 | 0 |
| Metabolism and nutrition disorders | |
| Appetite disorder | 1 | 0 |
| Psychiatric disorders | |
| Hallucinations
Hallucinations included hallucinations NOS as well as visual and hypnagogic hallucinations. | 4 | 0 |
| Disorientation | 3 | 2 |
| Anxiety | 2 | 0 |
| Depression | 2 | 0 |
| Psychomotor retardation | 2 | 0 |
| Binge eating | 1 | 0 |
| Depersonalization | 1 | 0 |
| Disinhibition | 1 | 0 |
| Euphoric mood | 1 | 0 |
| Mood swings | 1 | 0 |
| Stress symptoms | 1 | 0 |
| Nervous system disorders | |
| Headache | 19 | 16 |
| Somnolence | 15 | 2 |
| Dizziness | 12 | 5 |
| Memory disorders
Memory disorders include: memory impairment, amnesia, anterograde amnesia. | 3 | 0 |
| Balance disorder | 2 | 0 |
| Disturbance in attention | 2 | 0 |
| Hypoesthesia | 2 | 1 |
| Ataxia | 1 | 0 |
| Paresthesia | 1 | 0 |
| Eye disorders | |
| Visual disturbance | 3 | 0 |
| Eye redness | 2 | 0 |
| Vision blurred | 2 | 1 |
| Altered visual depth perception | 1 | 0 |
| Asthenopia | 1 | 0 |
| Ear and labyrinth disorders | |
| Vertigo | 2 | 0 |
| Tinnitus | 1 | 0 |
| Respiratory, thoracic and mediastinal disorders | | |
| Throat irritation | 1 | 0 |
| Gastrointestinal disorders | | |
| Nausea | 7 | 4 |
| Constipation | 2 | 0 |
| Abdominal discomfort | 1 | 0 |
| Abdominal tenderness | 1 | 0 |
| Frequent bowel movements | 1 | 0 |
| Gastroesophageal reflux disease | 1 | 0 |
| Vomiting | 1 | 0 |
| Skin and subcutaneous tissue disorders | | |
| Rash | 1 | 0 |
| Skin wrinkling | 1 | 0 |
| Urticaria | 1 | 0 |
| Musculoskeletal and connective tissue disorders | | |
| Back pain | 4 | 3 |
| Myalgia | 4 | 0 |
| Neck pain | 1 | 0 |
| Reproductive system and breast disorders | | |
| Menorrhagia | 1 | 0 |
| General disorders and administration site conditions | | |
| Fatigue | 3 | 2 |
| Asthenia | 1 | 0 |
| Chest discomfort | 1 | 0 |
| Investigations | | |
| Blood pressure increased | 1 | 0 |
| Body temperature increased | 1 | 0 |
| Injury, poisoning and procedural complications | | |
| Contusion | 1 | 0 |
| Social circumstances | | |
| Exposure to poisonous plant | 1 | 0 |
Table 2: Incidences of Treatment-Emergent Adverse Reactions in a 3-Week Placebo-Controlled Clinical Trial in Elderly (percentage of patients reporting)Body System
Adverse Reaction
Reactions reported by at least 1% of patients treated with AMBIEN CR and at greater frequency than in the placebo group. | AMBIEN CR
6.25 mg
| Placebo |
|---|
| (N=99) | (N=106) |
|---|
| Infections and infestations |
| Nasopharyngitis | 6 | 4 |
| Lower respiratory tract infection | 1 | 0 |
| Otitis externa | 1 | 0 |
| Upper respiratory tract infection | 1 | 0 |
| Psychiatric disorders | |
| Anxiety | 3 | 2 |
| Psychomotor retardation | 2 | 0 |
| Apathy | 1 | 0 |
| Depressed mood | 1 | 0 |
| Nervous system disorders | |
| Headache | 14 | 11 |
| Dizziness | 8 | 3 |
| Somnolence | 6 | 5 |
| Burning sensation | 1 | 0 |
| Dizziness postural | 1 | 0 |
| Memory disorders
Memory disorders include: memory impairment, amnesia, anterograde amnesia. | 1 | 0 |
| Muscle contractions involuntary | 1 | 0 |
| Paresthesia | 1 | 0 |
| Tremor | 1 | 0 |
| Cardiac disorders | |
| Palpitations | 2 | 0 |
| Respiratory, thoracic and mediastinal disorders | |
| Dry throat | 1 | 0 |
| Gastrointestinal disorders | |
| Flatulence | 1 | 0 |
| Vomiting | 1 | 0 |
| Skin and subcutaneous tissue disorders | |
| Rash | 1 | 0 |
| Urticaria | 1 | 0 |
| Musculoskeletal and connective tissue disorders | | |
| Arthralgia | 2 | 0 |
| Muscle cramp | 2 | 1 |
| Neck pain | 2 | 0 |
| Renal and urinary disorders | | |
| Dysuria | 1 | 0 |
| Reproductive system and breast disorders | | |
| Vulvovaginal dryness | 1 | 0 |
| General disorders and administration site conditions | | |
| Influenza like illness | 1 | 0 |
| Pyrexia | 1 | 0 |
| Injury, poisoning and procedural complications | | |
| Neck injury | 1 | 0 |
Dose Relationship for Adverse Reactions
There is evidence from dose comparison trials suggesting a dose relationship for many of the adverse reactions associated with zolpidem use, particularly for certain CNS and gastrointestinal adverse events.
Other Adverse Reactions Observed during the Premarketing Evaluation of AMBIEN CR
Other treatment-emergent adverse reactions associated with participation in AMBIEN CR studies (those reported at frequencies of <1%) were not different in nature or frequency to those seen in studies with immediate-release zolpidem tartrate, which are listed below.
Adverse Events Observed during the Premarketing Evaluation of Immediate-Release Zolpidem Tartrate
Immediate-release zolpidem tartrate was administered to 3,660 subjects in clinical trials throughout the U.S., Canada, and Europe. Treatment-emergent adverse events associated with clinical trial participation were recorded by clinical investigators using terminology of their own choosing. To provide a meaningful estimate of the proportion of individuals experiencing treatment-emergent adverse events, similar types of untoward events were grouped into a smaller number of standardized event categories and classified utilizing a modified World Health Organization (WHO) dictionary of preferred terms.
The frequencies presented, therefore, represent the proportions of the 3,660 individuals exposed to zolpidem, at all doses, who experienced an event of the type cited on at least one occasion while receiving zolpidem. All reported treatment-emergent adverse events are included, except those already listed in the table above of adverse events in placebo-controlled studies, those coding terms that are so general as to be uninformative, and those events where a drug cause was remote. It is important to emphasize that, although the events reported did occur during treatment with Ambien, they were not necessarily caused by it.
Adverse events are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent adverse events are defined as those occurring in greater than 1/100 subjects; infrequent adverse events are those occurring in 1/100 to 1/1,000 patients; rare events are those occurring in less than 1/1,000 patients.
Autonomic nervous system:Frequent: dry mouth. Infrequent: increased sweating, pallor, postural hypotension, syncope. Rare: abnormal accommodation, altered saliva, flushing, glaucoma, hypotension, impotence, increased saliva, tenesmus.
Body as a whole:Frequent: asthenia. Infrequent: chest pain, edema, falling, fever, malaise, trauma. Rare: allergic reaction, allergy aggravated, anaphylactic shock, face edema, hot flashes, increased ESR, pain, restless legs, rigors, tolerance increased, weight decrease.
Cardiovascular system:Infrequent: cerebrovascular disorder, hypertension, tachycardia. Rare: angina pectoris, arrhythmia, arteritis, circulatory failure, extrasystoles, hypertension aggravated, myocardial infarction, phlebitis, pulmonary embolism, pulmonary edema, varicose veins, ventricular tachycardia.
Central and peripheral nervous system:Frequent: ataxia, confusion, drowsiness, drugged feeling, euphoria, insomnia, lethargy, lightheadedness, vertigo. Infrequent: agitation, decreased cognition, detached, difficulty concentrating, dysarthria, emotional lability, hallucination, hypoesthesia, illusion, leg cramps, migraine, nervousness, paresthesia, sleeping (after daytime dosing), speech disorder, stupor, tremor. Rare: abnormal gait, abnormal thinking, aggressive reaction, apathy, appetite increased, decreased libido, delusion, dementia, depersonalization, dysphasia, feeling strange, hypokinesia, hypotonia, hysteria, intoxicated feeling, manic reaction, neuralgia, neuritis, neuropathy, neurosis, panic attacks, paresis, personality disorder, somnambulism, suicide attempts, tetany, yawning.
Gastrointestinal system:Frequent: diarrhea, dyspepsia, hiccup. Infrequent: anorexia, constipation, dysphagia, flatulence, gastroenteritis. Rare: enteritis, eructation, esophagospasm, gastritis, hemorrhoids, intestinal obstruction, rectal hemorrhage, tooth caries.
Hematologic and lymphatic system:Rare: anemia, hyperhemoglobinemia, leukopenia, lymphadenopathy, macrocytic anemia, purpura, thrombosis.
Immunologic system:Infrequent: infection. Rare: abscess herpes simplex herpes zoster, otitis externa, otitis media.
Liver and biliary system:Infrequent: abnormal hepatic function, increased SGPT. Rare: bilirubinemia, increased SGOT.
Metabolic and nutritional:Infrequent: hyperglycemia, thirst. Rare: gout, hypercholesteremia, hyperlipidemia, increased alkaline phosphatase, increased BUN, periorbital edema.
Musculoskeletal system:Infrequent: arthritis. Rare: arthrosis, muscle weakness, sciatica, tendinitis.
Reproductive system:Infrequent: menstrual disorder, vaginitis. Rare: breast fibroadenosis, breast neoplasm, breast pain.
Respiratory system:Frequent: sinusitis. Infrequent: bronchitis, coughing, dyspnea. Rare: bronchospasm, respiratory depression, epistaxis, hypoxia, laryngitis, pneumonia.
Skin and appendages:Infrequent: pruritus. Rare: acne, bullous eruption, dermatitis, furunculosis, injection-site inflammation, photosensitivity reaction, urticaria.
Special senses:Frequent: diplopia, vision abnormal. Infrequent: eye irritation, eye pain, scleritis, taste perversion, tinnitus. Rare: conjunctivitis, corneal ulceration, lacrimation abnormal, parosmia, photopsia.
Urogenital system:Frequent: urinary tract infection. Infrequent: cystitis, urinary incontinence. Rare: acute renal failure, dysuria, micturition frequency, nocturia, polyuria, pyelonephritis, renal pain, urinary retention.
CNS Depressants
Coadministration of zolpidem with other CNS depressants increases the risk of CNS depression. Concomitant use of zolpidem with these drugs may increase drowsiness and psychomotor impairment, including impaired driving ability
[see
Warnings and Precautions (5.1,
5.2)].
Zolpidem tartrate was evaluated in healthy volunteers in single-dose interaction studies for several CNS drugs.
Alcohol
An additive adverse effect on psychomotor performance between alcohol and oral zolpidem was demonstrated
[see
Warnings and Precautions (5.1,
5.2)]
.
Opioids
The concomitant use of AMBIEN CR with opioids may increase the risk of respiratory depression. Limit dosage and duration of concomitant use of AMBIEN and opioids
[see
Dosage and Administration (2.3),
Warnings and Precautions (5.7)]
.
Imipramine, Chlorpromazine
Imipramine in combination with zolpidem produced no pharmacokinetic interaction other than a 20% decrease in peak levels of imipramine, but there was an additive effect of decreased alertness. Similarly, chlorpromazine in combination with zolpidem produced no pharmacokinetic interaction, but there was an additive effect of decreased alertness and psychomotor performance
[see
Clinical Pharmacology (12.3)]
.
Sertraline
Concomitant administration of zolpidem and sertraline increases exposure to zolpidem
[see
Clinical Pharmacology (12.3)]
.
Fluoxetine
After multiple doses of zolpidem tartrate and fluoxetine an increase in the zolpidem half-life (17%) was observed. There was no evidence of an additive effect in psychomotor performance
[see
Clinical Pharmacology (12.3)]
.
Haloperidol
A study involving haloperidol and zolpidem revealed no effect of haloperidol on the pharmacokinetics or pharmacodynamics of zolpidem. The lack of a drug interaction following single-dose administration does not predict the absence of an effect following chronic administration
[see
Clinical Pharmacology (12.3)]
.
CYP3A4 Inducers
Rifampin
Rifampin, a CYP3A4 inducer, significantly reduced the exposure to and the pharmacodynamic effects of zolpidem. Use of Rifampin in combination with zolpidem may decrease the efficacy of zolpidem and is not recommended
[see
Clinical Pharmacology (12.3)]
.
St. John's wort
Use of St. John's wort, a CYP3A4 inducer, in combination with zolpidem may decrease blood levels of zolpidem and is not recommended.
CYP3A4 Inhibitors
Ketoconazole
Ketoconazole, a potent CYP3A4 inhibitor, increased the exposure to and pharmacodynamic effects of zolpidem. Consideration should be given to using a lower dose of zolpidem when a potent CYP3A4 inhibitor and zolpidem are given together
[see
Clinical Pharmacology (12.3)]
.
Risk Summary
Neonates born to mothers using zolpidem late in the third trimester of pregnancy have been reported to experience symptoms of respiratory depression and sedation
[see
Clinical Considerationsand
Data]
. Published data on the use of zolpidem during pregnancy have not reported a clear association with zolpidem and major birth defects
[see
Data]
. Oral administration of zolpidem to pregnant rats and rabbits did not indicate a risk for adverse effects on fetal development at clinically relevant doses
[see
Data]
.
The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2%–4% and 15%–20%, respectively.
Clinical Considerations
Fetal/neonatal adverse reactions
Zolpidem crosses the placenta and may produce respiratory depression and sedation in neonates. Monitor neonates exposed to AMBIEN CR during pregnancy and labor for signs of excess sedation, hypotonia, and respiratory depression and manage accordingly.
Data
Human data
Published data from observational studies, birth registries, and case reports on the use of zolpidem during pregnancy do not report a clear association with zolpidem and major birth defects.
There are limited postmarketing reports of severe to moderate cases of respiratory depression that occurred after birth in neonates whose mothers had taken zolpidem during pregnancy. These cases required artificial ventilation or intratracheal intubation. The majority of neonates recovered within hours to a few weeks after birth once treated.
Zolpidem has been shown to cross the placenta.
Animal data
Oral administration of zolpidem to pregnant rats during the period of organogenesis at 4, 20, and 100 mg base/kg/day, which are approximately 4, 20, and 100 times the maximum recommended human dose (MRHD) of 12.5 mg/day (10 mg zolpidem base) based on mg/m
2body surface area, caused delayed fetal development (incomplete fetal skeletal ossification) at maternally toxic (ataxia) doses 20 and 100 times the MRHD based on mg/m
2body surface area.
Oral administration of zolpidem to pregnant rabbits during the period of organogenesis at 1, 4, and 16 mg base/kg/day, which are approximately 2, 8, and 30 times the MRHD of 12.5 mg/day (10 mg zolpidem base) based on mg/m
2body surface area caused embryo-fetal death and delayed fetal development (incomplete fetal skeletal ossification) at a maternally toxic (decreased body weight gain) dose 30 times the MRHD based on mg/m
2body surface area.
Oral administration of zolpidem to pregnant rats from day 15 of gestation through lactation at 4, 20, and 100 mg base/kg/day, which are approximately 4, 20, and 100 times the MRHD of 12.5 mg/day (10 mg zolpidem base) based on a mg/m
2body surface area, delayed offspring growth and decreased survival at doses 20 and 100 times, respectively, the MRHD based on mg/m
2body surface area.
Risk Summary
Limited data from published literature report the presence of zolpidem in human milk. There are reports of excess sedation in infants exposed to zolpidem through breastmilk
[see
Clinical Considerations].
There is no information on the effects of zolpidem on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for AMBIEN CR and any potential adverse effects on the breastfed infant from AMBIEN CR or from the underlying maternal condition.
Clinical Considerations
Infants exposed to AMBIEN CR through breastmilk should be monitored for excess sedation, hypotonia, and respiratory depression. A lactating woman may consider interrupting breastfeeding and pumping and discarding breast milk during treatment and for 23 hours (approximately 5 elimination half-lives) after AMBIEN CR administration in order to minimize drug exposure to a breast fed infant.
Absorption
Following administration of AMBIEN CR, administered as a single 12.5 mg dose in healthy male adult subjects, the mean peak concentration (C
max) of zolpidem was 134 ng/mL (range: 68.9 to 197 ng/ml) occurring at a median time (T
max) of 1.5 hours. The mean AUC of zolpidem was 740 ng∙hr/mL (range: 295 to 1359 ng∙hr/mL).
A food-effect study in 45 healthy subjects compared the pharmacokinetics of AMBIEN CR 12.5 mg when administered while fasting or within 30 minutes after a meal. Results demonstrated that with food, mean AUC and C
maxwere decreased by 23% and 30%, respectively, while median T
maxwas increased from 2 hours to 4 hours. The half-life was not changed. These results suggest that, for faster sleep onset, AMBIEN CR should not be administered with or immediately after a meal.
Distribution
Total protein binding was found to be 92.5 ± 0.1% and remained constant, independent of concentration between 40 and 790 ng/mL.
Metabolism
Zolpidem is converted to inactive metabolites that are eliminated primarily by renal excretion.
Elimination
When AMBIEN CR was administered as a single 12.5 mg dose in healthy male adult subjects, the mean zolpidem elimination half-life was 2.8 hours (range: 1.62 to 4.05 hr).
Elderly
In 24 elderly (≥65 years) healthy subjects administered a single 6.25 mg dose of AMBIEN CR, the mean peak concentration (C
max) of zolpidem was 70.6 (range: 35.0 to 161) ng/mL occurring at a median time (T
max) of 2.0 hours. The mean AUC of zolpidem was 413 ng∙hr/mL (range: 124 to 1190 ng∙hr/mL) and the mean elimination half-life was 2.9 hours (range: 1.59 to 5.50 hours).
Hepatic impairment
AMBIEN CR was not studied in patients with hepatic impairment. The pharmacokinetics of an immediate-release formulation of zolpidem tartrate in eight patients with chronic hepatic insufficiency was compared to results in healthy subjects. Following a single 20 mg oral zolpidem tartrate dose, mean C
maxand AUC were found to be two times (250 vs 499 ng/mL) and five times (788 vs 4,203 ng∙hr/mL) higher, respectively, in hepatically compromised patients. T
maxdid not change. The mean half-life in cirrhotic patients of 9.9 hr (range: 4.1 to 25.8 hr) was greater than that observed in normal subjects of 2.2 hr (range: 1.6 to 2.4 hr)
[see
Dosage and Administration (2.2),
Warnings and Precautions (5.8),
Use in Specific Populations (8.7)]
.
Renal impairment
AMBIEN CR was not studied in patients with renal impairment. The pharmacokinetics of an immediate-release formulation of zolpidem tartrate were studied in 11 patients with end-stage renal failure (mean Cl
Cr= 6.5 ± 1.5 mL/min) undergoing hemodialysis three times a week, who were dosed with zolpidem tartrate 10 mg orally each day for 14 or 21 days. No statistically significant differences were observed for C
max, T
max, half-life, and AUC between the first and last day of drug administration when baseline concentration adjustments were made. Zolpidem was not hemodialyzable. No accumulation of unchanged drug appeared after 14 or 21 days. Zolpidem pharmacokinetics was not significantly different in renally impaired patients. No dosage adjustment is necessary in patients with compromised renal function.
Special Populations
CNS depressants
Coadministration of zolpidem with other CNS depressants increases the risk of CNS depression
[see
Warnings and Precautions (5.2)].
Zolpidem tartrate was evaluated in healthy volunteers in single-dose interaction studies for several CNS drugs. Imipramine in combination with zolpidem produced no pharmacokinetic interaction other than a 20% decrease in peak levels of imipramine, but there was an additive effect of decreased alertness. Similarly, chlorpromazine in combination with zolpidem produced no pharmacokinetic interaction, but there was an additive effect of decreased alertness and psychomotor performance.
A study involving haloperidol and zolpidem revealed no effect of haloperidol on the pharmacokinetics or pharmacodynamics of zolpidem. The lack of a drug interaction following single-dose administration does not predict the absence of an effect following chronic administration.
An additive adverse effect on psychomotor performance between alcohol and oral zolpidem was demonstrated
[see
Warnings and Precautions (5.2)].
Following five consecutive nightly doses at bedtime of oral zolpidem tartrate 10 mg in the presence of sertraline 50 mg (17 consecutive daily doses, at 7:00 am, in healthy female volunteers), zolpidem C
maxwas significantly higher (43%) and T
maxwas significantly decreased (-53%). Pharmacokinetics of sertraline and N-desmethylsertraline were unaffected by zolpidem.
A single-dose interaction study with zolpidem tartrate 10 mg and fluoxetine 20 mg at steady-state levels in male volunteers did not demonstrate any clinically significant pharmacokinetic or pharmacodynamic interactions. When multiple doses of zolpidem and fluoxetine were given at steady state and the concentrations evaluated in healthy females, an increase in the zolpidem half-life (17%) was observed. There was no evidence of an additive effect in psychomotor performance.
Drugs that affect drug metabolism via cytochrome P450
Some compounds known to inhibit CYP3A may increase exposure to zolpidem. The effect of inhibitors of other P450 enzymes on the pharmacokinetics of zolpidem is unknown.
A single-dose interaction study with zolpidem tartrate 10 mg and itraconazole 200 mg at steady-state levels in male volunteers resulted in a 34% increase in AUC
0–∞of zolpidem tartrate. There were no pharmacodynamic effects of zolpidem detected on subjective drowsiness, postural sway, or psychomotor performance.
A single-dose interaction study with zolpidem tartrate 10 mg and rifampin 600 mg at steady-state levels in female subjects showed significant reductions of the AUC (-73%), C
max(-58%), and T
1/2(-36%) of zolpidem together with significant reductions in the pharmacodynamic effects of zolpidem tartrate. Rifampin, a CYP3A4 inducer, significantly reduced the exposure to and the pharmacodynamic effects of zolpidem
[see
Drug Interactions (7.2)]
.
Similarly, St. John's wort, a CYP3A4 inducer, may also decrease the blood levels of zolpidem.
A single-dose interaction study with zolpidem tartrate 5 mg and ketoconazole, a potent CYP3A4 inhibitor, given as 200 mg twice daily for 2 days increased C
maxof zolpidem (30%) and the total AUC of zolpidem (70%) compared to zolpidem alone and prolonged the elimination half-life (30%) along with an increase in the pharmacodynamic effects of zolpidem
[see
Drug Interactions (7.2)]
.
Additionally, fluvoxamine (a strong inhibitor of CYP1A2 and a weak inhibitor of CYP3A4 and CYP2C9) and ciprofloxacin (a strong inhibitor of CYP1A2 and a moderate inhibitor of CYP3A4) are also likely to inhibit zolpidem's metabolic pathways, potentially leading to an increase in zolpidem exposure.
Other drugs with no interactions with zolpidem
A study involving cimetidine/zolpidem tartrate and ranitidine/zolpidem tartrate combinations revealed no effect of either drug on the pharmacokinetics or pharmacodynamics of zolpidem.
Zolpidem tartrate had no effect on digoxin pharmacokinetics and did not affect prothrombin time when given with warfarin in healthy subjects.
Drug Interactions
Next-Day Residual Effects
In five clinical studies (three controlled studies in adults [18–64 years of age] administered AMBIEN CR 12.5 mg and two controlled studies in the elderly [≥65 years of age] administered AMBIEN CR 6.25 mg or 12.5 mg), the effect of AMBIEN CR on vigilance, memory, or motor function were assessed using neurocognitive tests. In these studies, no significant decrease in performance was observed eight hours after a nighttime dose. In addition, no evidence of next-day residual effects was detected with AMBIEN CR 12.5 mg and 6.25 mg using self-ratings of sedation.
During the 3-week studies, next-day somnolence was reported by 15% of the adult patients who received 12.5 mg AMBIEN CR versus 2% of the placebo group; next-day somnolence was reported by 6% of the elderly patients who received 6.25 mg AMBIEN CR versus 5% of the placebo group
[see
Adverse Reactions (6)]
. In a 6-month study, the overall incidence of next-day somnolence was 5.7% in the AMBIEN CR group as compared to 2% in the placebo group.
Rebound Effects
Rebound insomnia, defined as a dose-dependent worsening in sleep parameters (latency, sleep efficiency, and number of awakenings) compared with baseline following discontinuation of treatment, is observed with short- and intermediate-acting hypnotics. In the two 3-week placebo-controlled studies in patients with primary insomnia, a rebound effect was only observed on the first night after abrupt discontinuation of AMBIEN CR. On the second night, there was no worsening compared to baseline in the AMBIEN CR group.
In a 6-month placebo-controlled study in which AMBIEN CR was taken as needed (3 to 7 nights per week), within the first month a rebound effect was observed for Total Sleep Time (not for WASO) during the first night off medication. After this first month period, no further rebound insomnia was observed. After final treatment discontinuation no rebound was observed.
Complex Sleep Behaviors
Instruct patients and their families that AMBIEN CR may cause complex sleep behaviors, including sleep-walking, sleep-driving, preparing and eating food, making phone calls, or having sex while not being fully awake. Serious injuries and death have occurred during complex sleep behavior episodes. Tell patients to discontinue AMBIEN CR and notify their healthcare provider immediately if they develop any of these symptoms
[see
Boxed Warning,
Warnings and Precautions (5.1)]
.
CNS-Depressant Effects and Next-Day Impairment
Tell patients that AMBIEN CR can cause next-day impairment even when used as prescribed, and that this risk is increased if dosing instructions are not carefully followed. Caution patients against driving and other activities requiring complete mental alertness the day after use. Inform patients that impairment can be present despite feeling fully awake. Advise patients that increased drowsiness and decreased consciousness may increase the risk of falls in some patients
[see
Warnings and Precautions (5.2)]
.
Severe Anaphylactic and Anaphylactoid Reactions
Inform patients that severe anaphylactic and anaphylactoid reactions have occurred with zolpidem. Describe the signs/symptoms of these reactions and advise patients to seek medical attention immediately if any of them occur
[see
Warnings and Precautions (5.4)]
.
Suicide
Tell patients to immediately report any suicidal thoughts.
Alcohol and other Drugs
Ask patients about alcohol consumption, medicines they are taking, and drugs they may be taking without a prescription. Advise patients not to use AMBIEN CR if they drank alcohol that evening or before bed.
Concomitant Use with Opioids
Inform patients and caregivers that potentially serious additive effects may occur if AMBIEN CR is used with opioids and not to use such drugs concomitantly unless supervised by a healthcare provider
[Warnings and Precautions (5.2, 5.7), Drug Interactions (7.1)].
Tolerance, Abuse, and Dependence
Tell patients not to increase the dose of AMBIEN CR on their own, and to inform you if they believe the drug "does not work."
Administration Instructions
Patients should be counseled to take AMBIEN CR right before they get into bed and only when they are able to stay in bed a full night (7–8 hours) before being active again. AMBIEN CR tablets should not be taken with or immediately after a meal. Advise patients NOT to take AMBIEN CR if they drank alcohol that evening.
Pregnancy
Advise patients to notify their healthcare provider if they become pregnant or intend to become pregnant during treatment with AMBIEN CR. Advise patients that use of AMBIEN CR late in the third trimester may cause respiratory depression and sedation in neonates. Advise mothers who used AMBIEN CR during the late third trimester of pregnancy to monitor neonates for signs of sleepiness (more than usual), breathing difficulties, or limpness
[see
Use in Specific Populations (8.1)].
Lactation
Advise breastfeeding mothers using AMBIEN CR to monitor infants for increased sleepiness (more than usual), breathing difficulties, or limpness. Instruct breastfeeding mothers to seek immediate medical care if they notice these signs. A lactating woman may consider pumping and discarding breastmilk during treatment and for 23 hours after AMBIEN CR administration to minimize drug exposure to a breastfed infant
[see
Use in Specific Populations (8.2)]
.
Marketed by:
Cosette Pharmaceuticals, Inc.
South Plainfield, NJ 07080
8-AMBCRCP1