Increased risk of hypertensive reactions w/ MAOIs. Increased bupropion exposure but decreased hydroxybupropion exposure w/ ticlopidine & clopidogrel (CYP2B6 inhibitors). Decreased exposure of bupropion & hydroxybupropion w/ ritonavir, lopinavir or efavirenz (CYP2B6 inducers). Decreased bupropion exposure w/ carbamazepine, phenobarb, phenytoin (CYP2B6 inducers). Increased exposure of CYP2D6 substrates [including certain antidepressants (eg, venlafaxine, nortriptyline, imipramine, desipramine, paroxetine, fluoxetine, sertraline), antipsychotics (eg, haloperidol, risperidone, thioridazine), β-blockers (eg, metoprolol), type 1C antiarrhythmics (eg, propafenone, flecainide)]. Potential reduced efficacy of drugs that require metabolic activation by CYP2D6 to be effective (eg, tamoxifen). Decreased plasma levels of digoxin. Use extreme caution when co-administering w/ other drugs that lower seizure threshold (eg, other bupropion products, antipsychotics, antidepressants, theophylline, systemic corticosteroids). CNS toxicity w/ levodopa or amantadine. Adverse neuropsychiatric events or reduced alcohol tolerance w/ drinking of alcohol.