Table 1 includes clinically significant drug interactions with Oxycodone Hydrochloride Oral Solution.
Inhibitors of CYP3A4 and CYP2D6 |
Clinical Impact: | The concomitant use of Oxycodone Hydrochloride Oral Solution and CYP3A4 inhibitors can increase the plasma concentration of oxycodone, resulting in increased or prolonged opioid effects. These effects could be more pronounced with concomitant use of Oxycodone Hydrochloride Oral Solution and CYP2D6 and CYP3A4 inhibitors, particularly when an inhibitor is added after a stable dose of Oxycodone Hydrochloride Oral Solution is achieved [see Warnings and Precautions ( 5.6) ]. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the oxycodone plasma concentration will decrease [see Clinical Pharmacology ( 12.3) ], resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to oxycodone. |
Intervention: | If concomitant use is necessary, consider dosage reduction of Oxycodone Hydrochloride Oral Solution until stable drug effects are achieved Monitor patients for respiratory depression and sedation at frequent intervals. If a CYP3A4 inhibitor is discontinued, consider increasing the Oxycodone Hydrochloride Oral Solution dosage until stable drug effects are achieved [see Dosage and Administration (2.2)]. Monitor for signs of opioid withdrawal. |
Examples | Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), protease inhibitors (e.g., ritonavir) |
CYP3A4 Inducers |
Clinical Impact: | The concomitant use of Oxycodone Hydrochloride Oral Solution and CYP3A4 inducers can decrease the plasma concentration of oxycodone [see Clinical Pharmacology ( 12.3) ], resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to oxycodone [see Warnings and Precautions ( 5.6) ]. After stopping a CYP3A4 inducer, as the effects of the inducer decline, the oxycodone plasma concentration will increase [see Clinical Pharmacology ( 12.3) ], which could increase or prolong both the therapeutic effects and adverse reactions, and may cause serious respiratory depression. |
Intervention: | If concomitant use is necessary, consider increasing the Oxycodone Hydrochloride Oral Solution dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. If a CYP3A4 inducer is discontinued, consider Oxycodone Hydrochloride Oral Solution dosage reduction and monitor for signs of respiratory depression. |
Examples | Rifampin, carbamazepine, phenytoin |
Benzodiazepines and other Central Nervous System (CNS) Depressants |
Clinical Impact: | Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants including alcohol, increases the risk of respiratory depression, profound sedation, coma, and death. |
Intervention: | Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Follow patients closely for signs of respiratory depression and sedation [see Warnings and Precautions ( 5.7) ] . |
Examples: | Benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, other opioids, alcohol. |
Serotonergic Drugs |
Clinical Impact: | The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome [see Warnings and Precautions ( 5.9)]. |
Intervention: | If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue Oxycodone Hydrochloride Oral Solution if serotonin syndrome is suspected. |
Examples: | Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue). |
Monoamine Oxidase Inhibitors (MAOIs) |
Clinical Impact: | MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (e.g., respiratory depression, coma) [see Warnings and Precautions ( 5.4) ] . |
Intervention: | The use of Oxycodone Hydrochloride Oral Solution is not recommended for patients taking MAOIs or within 14 days of stopping such treatment. If urgent use of an opioid is necessary, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. |
Examples | phenelzine, tranylcypromine, linezolid |
Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics |
Clinical Impact: | May reduce the analgesic effect of Oxycodone Hydrochloride Oral Solution and/or precipitate withdrawal symptoms. |
Intervention: | Avoid concomitant use. |
Examples: | butorphanol, nalbuphine, pentazocine, buprenorphine |
Muscle Relaxants |
Clinical Impact: | Oxycodone may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. |
Intervention: | Monitor patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of Oxycodone Hydrochloride Oral Solution and/or the muscle relaxant as necessary. |
Diuretics |
Clinical Impact: | Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. |
Intervention: | Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. |
Anticholinergic Drugs |
Clinical Impact: | The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. |
Intervention: | Monitor patients for signs of urinary retention or reduced gastric motility when Oxycodone Hydrochloride Oral Solution is used concomitantly with anticholinergic drugs. |
Clinical Presentation
Acute overdose with Oxycodone Hydrochloride Oral Solution can be manifested by respiratory depression, somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, constricted pupils, and, in some cases, pulmonary edema, bradycardia, hypotension, partial or complete airway obstruction, atypical snoring, and death. Marked mydriasis rather than miosis may be seen with hypoxia in overdose situations [see Clinical Pharmacology ( 12.2) ].
Treatment of Overdose
In case of overdose, priorities are the reestablishment of a patent and protected airway and institution of assisted or controlled ventilation, if needed. Employ other supportive measures (including oxygen and vasopressors) in the management of circulatory shock and pulmonary edema as indicated. Cardiac arrest or arrhythmias will require advanced life-support techniques.
The opioid antagonists, naloxone or nalmefene, are specific antidotes to respiratory depression resulting from opioid overdose. For clinically significant respiratory or circulatory depression secondary to oxycodone overdose, administer an opioid antagonist. Opioid antagonists should not be administered in the absence of clinically significant respiratory or circulatory depression secondary to oxycodone overdose.
Because the duration of opioid reversal is expected to be less than the duration of action of oxycodone in Oxycodone Hydrochloride Oral Solution, carefully monitor the patient until spontaneous respiration is reliably re-established. If the response to an opioid antagonist is suboptimal or only brief in nature, administer additional antagonist as directed by the product’s prescribing information.
In an individual physically dependent on opioids, administration of the recommended usual dosage of the antagonist will precipitate an acute withdrawal syndrome. The severity of the withdrawal symptoms experienced will depend on the degree of physical dependence and the dose of the antagonist administered. If a decision is made to treat serious respiratory depression in the physically dependent patient, administration of the antagonist should be initiated with care and by titration with smaller than usual doses of the antagonist.
Effects on the Cardiovascular System
Oxycodone produces peripheral vasodilation which may result in orthostatic hypotension or syncope. Manifestations of histamine release and/or peripheral vasodilation may include pruritus, flushing, red eyes and sweating and/or orthostatic hypotension.
Effects on the Endocrine System
Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and luteinizing hormone (LH) in humans [see Adverse Reactions ( 6) ]. They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon.
Chronic use of opioids may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date [see Adverse Reactions ( 6) ].
Effects on the Immune System
Opioids have been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive.
Concentration–Efficacy Relationships
The minimum effective analgesic concentration will vary widely among patients, especially among patients who have been previously treated with potent agonist opioids. The minimum effective analgesic concentration of oxycodone for any individual patient may increase over time due to an increase in pain, the development of a new pain syndrome and/or the development of analgesic tolerance [see Dosage and Administration ( 2.1, 2.2) ].
Concentration–Adverse Reaction Relationships
There is a relationship between increasing oxycodone plasma concentration and increasing frequency of dose-related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid-tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions [see Dosage and Administration ( 2.1, 2.2, 2.3) ].
Absorption
The oral bioavailability of oxycodone is 60 - 87%. This high oral bioavailability (compared to other oral opioids) is due to lower pre-systemic and/or first-pass metabolism of oxycodone.
Food Effect
Presence of food may slightly delay the rate (Cmax and Tmax) and enhance the extent of absorption (AUC) of oxycodone from Oxycodone Hydrochloride Oral Solution. Overall, food is not expected to have a clinically significant impact on the absorption of Oxycodone Hydrochloride Oral Solution.
Distribution
Following intravenous administration, the volume of distribution (Vss) for oxycodone was 2.6 L/kg. Plasma protein binding of oxycodone at 37°C and a pH of 7.4 was about 45%. Oxycodone has been found in breast milk [seeUse in Specific Populations ( 8.2) ].
Elimination
Metabolism
Oxycodone hydrochloride is extensively metabolized to noroxycodone, oxymorphone, noroxymorphone, which are subsequently glucuronidated. CYP3A4 mediated N-demethylation to noroxycodone is the primary metabolic pathway of oxycodone with a less contribution from CYP2D6 mediated O-demethylation to oxymorphone. Therefore, the formation of these and related metabolites can, in theory, be affected by other drugs. The major circulating metabolite is noroxycodone with an AUC ratio of 0.6 relative to that of oxycodone. Noroxycodone is reported to be a considerably weaker analgesic than oxycodone. Oxymorphone, although possessing analgesic activity, is present in the plasma only in low concentrations. The correlation between oxymorphone concentrations and opioid effects was much less than that seen with oxycodone plasma concentrations. The analgesic activity profile of other metabolites is not known.
Excretion
Oxycodone and its metabolites are excreted primarily via the kidney. The amounts measured in the urine have been reported as follows: free oxycodone up to 19%; conjugated oxycodone up to 50%; free oxymorphone 0%; conjugated oxymorphone ≤ 14%; both free and conjugated noroxycodone have been found in the urine but not quantified. The total plasma clearance was 0.8 L/min for adults. Apparent elimination half-life of oxycodone following the administration of Oxycodone Hydrochloride Oral Solution was approximately 3.5 hours.
Special Populations
Age: Geriatric Population
Information obtained from oxycodone tablets indicate that the plasma concentrations of oxycodone did not appear to be increased in patients over of the age of 65.
Hepatic Impairment
Because oxycodone is extensively metabolized in the liver, its clearance may decrease in hepatic-impaired patients. A dose adjustment is recommended in these patients [see Use in Special Populations ( 8.6) ] .
Renal Impairment
Because this drug is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function, a dose reduction is recommended for renal impaired patients. [see Use in Special Populations ( 8.7) ] .
Drug Interactions Studies
CYP3A4 Inhibitors
CYP3A4 is the major enzyme involved in noroxycodone formation. A published study showed that the co-administration of voriconazole, a CYP3A4 inhibitor, increased oxycodone AUC and C max by 3.6 and 1.7 fold, respectively.
CYP3A4 Inducers
A published study showed that the co-administration of rifampin, a drug metabolizing enzyme inducer, decreased oxycodone AUC and C max values by 86% and 63%, respectively.
CYP2D6 Inhibitors
Oxycodone is metabolized in part to oxymorphone via the cytochrome p450 isoenzyme CYP2D6. While this pathway may be blocked by a variety of drugs (e.g., certain cardiovascular drugs and antidepressants), such blockade has not yet been shown to be of clinical significance with this agent.
Oxycodone Hydrochloride Oral Solution, USP, 5 mg per 5 mL (1 mg/mL) is available as follows:
NDC# 0904-6678-40: 500 mL bottle packaged with calibrated measuring cup
NDC# 0904-6828-94: Case contains 40 unit dose cups of 5 mL, packaged in 4 trays of 10 unit dose cups each
NDC# 0904-6828-92: Case contains 50 unit dose cups of 5 mL, packaged in 5 trays of 10 unit dose cups each
Dispense in a tight, light-resistant container as defined in the USP/NF.
Store at controlled room temperature 20°-25°C (68°- 77°F); excursions are permitted to 15° - 30°C (59° - 86°F). [See USP Controlled Room Temperature]
Store Oxycodone Hydrochloride Oral Solution securely and dispose of properly [see Patient Counseling Information (17)].