Interactions between your selected drugs
bupropion ↔ oxycodone
Applies to: Wellbutrin (bupropion), oxycodone
MONITOR CLOSELY: The use of bupropion is associated with a dose-related risk of seizures. The estimated incidence of seizures is approximately 0.1% at dosages up to 300 mg/day and 0.4% at dosages between 300 to 450 mg/day, but increases almost tenfold between 450 mg and 600 mg/day. The risk may also be increased during coadministration with selective serotonin reuptake inhibitors (SSRI antidepressants or anorectics), monoamine oxidase inhibitors, neuroleptic agents, central nervous system stimulants, opioids, tricyclic antidepressants, other tricyclic compounds (e.g., cyclobenzaprine, phenothiazines), systemic steroids, and/or any substance that can reduce the seizure threshold (e.g., carbapenems, cholinergic agents, fluoroquinolones, interferons, chloroquine, mefloquine, lindane, theophylline). These agents are often individually epileptogenic and may have additive effects when combined.
MANAGEMENT: Extreme caution is advised if bupropion is administered with any substance that can reduce the seizure threshold, particularly in the elderly and in patients with a history of seizures or other risk factors for seizures (e.g., head trauma; brain tumor; severe hepatic cirrhosis; metabolic disorders; CNS infections; excessive use of alcohol or sedatives; addiction to opiates, cocaine, or stimulants; diabetes treated with oral hypoglycemic agents or insulin). Bupropion as well as concomitant medications should be initiated at the lower end of the dose range and titrated gradually if feasible. The total dose of bupropion should generally not exceed 450 mg/day (or 150 mg every other day in patients with severe hepatic cirrhosis). Bupropion should be discontinued and not restarted in patients who experience a seizure during treatment.
nortriptyline ↔ bupropion
Applies to: nortriptyline, Wellbutrin (bupropion)
MONITOR CLOSELY: The concomitant use of bupropion and tricyclic antidepressants (TCAs) may potentiate the risk of seizures. These agents are individually epileptogenic and may have additive effects on the seizure threshold. Additionally, bupropion can increase the plasma concentrations of some TCAs due to inhibition of CYP450 2D6. In one case report, plasma levels of imipramine and its metabolite, desipramine, increased approximately fourfold in a 64-year-old woman following the addition of bupropion 225 mg/day. Plasma levels of desipramine were increased twofold more than the imipramine levels, which is consistent with the fact that desipramine is primarily metabolized by CYP450 2D6 while imipramine is also metabolized by other CYP450 isoenzymes. Similarly, a 62-year-old woman with no history of seizures developed a generalized tonic-clonic seizure in association with toxic trimipramine plasma levels following the addition of bupropion. No further seizures occurred following dosage reductions of both drugs. In a study of 15 male volunteers who were extensive metabolizers of CYP450 2D6, pretreatment with bupropion (150 mg twice daily) increased the peak plasma concentration (Cmax), area under the concentration-time curve (AUC) and half-life of desipramine (50 mg single dose) by an average of 2-, 5-, and 2-fold, respectively. The effect was present for at least 7 days after the last dose of bupropion.
MANAGEMENT: The manufacturer advises extreme caution if bupropion is coadministered with TCAs. Low initial TCA dosages with gradual titration are recommended. In patients who are already stabilized on TCA therapy, plasma TCA levels and pharmacologic response should be monitored more closely whenever bupropion is added to or withdrawn from therapy, and the TCA dosage adjusted as necessary. Patients should be advised to notify their physician if they experience seizures or increased TCA adverse effects such as somnolence, dry mouth, urinary retention, orthostasis, tachycardia, or irregular heartbeats.
nortriptyline ↔ oxycodone
Applies to: nortriptyline, oxycodone
MONITOR: Central nervous system- and/or respiratory-depressant effects may be additively or synergistically increased in patients taking multiple drugs that cause these effects, especially in elderly or debilitated patients.
MANAGEMENT: During concomitant use of these drugs, patients should be monitored for potentially excessive or prolonged CNS and respiratory depression. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.