Bupropion interactions

Bupropion Hydrochloride Bupropion interacts with levodopa, nicotine, alcohol, and drugs that affect hepatic metabolic enzymes. It lowers the seizure threshold and potentiates the seizure threshold-lowering effect of other antidepressants.135... 

Marcucci C, Sandson NB, Dunlap JA. Linezolid-bupropion interaction as possible etiology of... 

Some of the clinical issues have been reviewed recently by Zanger and Klein [607]. The major issues are interindividual variations due to induction and genetic variation as well as some inhibitions. The effects of genetic variation have been reported for the drag efavirenz (used for HIV) [608-611]. Another drag in which genetic variations make an in vivo difference is bupropion, used in smoking cessation therapy [612, 613]. Efavirenz-bupropion interactions have also been reported [614]. 

Hesse LM, Venkatakrishnan K, Court MH, et al. CYP2B6 mediates the in vitro hydroxyla-tion of bupropion potential drug interactions with other antidepressants. Drug Metab Dispos... 

Case reports have suggested that adding stimulant medications or combining a SSRI and a TCA or bupropion may also be effective (APA, 2000), but these combinations need to be done with caution, given the possibility of drug interactions (e.g., SSRIs cytochrome inhibition leading to toxic TCA levels). Additionally, in adults, the combination of antidepressants and psychotherapy (CBT, IPT) for patients with severe or treatment-resistant depression has been found useful (APA, 2000 Keller et al., 2000). 

SSRIs reduce dopamine cell firing in the substantia nigra through their effects on serotonin input to this nucleus. The net result is that they can cause generally mild extrapyramidal side effects (EPS) (500). The most common are restlessness and tremors. The same mechanism is probably responsible for their interaction with other agents that affect central motor systems. Thus, the SSRIs can potentiate the tremor seen with lithium, as well as EPS caused by antipsychotics, bupropion, and psychostimulants (376, 500). 

Consistent with its most potent known mechanism of action, bupropion is an indirect dopamine agonist via its inhibition of the neuronal uptake pump for dopamine (503, 504). Hence, bupropion can potentiate the effects of other dopamine agonists. This interaction does not typically cause serious problems and may even be advantageous in specific instances such as patients with Parkinson s disease plus a depressive disorder. Because of its ability to inhibit NE uptake, bupropion would be prone to the same interactions as NSRIs such as desipramine and reboxetine. 

Three randomized clinical trials support the efficacy of bupropion in ADHD. The first used doses up to 6 mg/kg (98) the other two used doses of 100 to 300 mg per day in equally divided daily doses spaced at least 6 hours apart ( 99, 100). The concern with bupropion is its seizure risk, which requires that its daily dose stay below 450 mg per day in adults (i.e., approximately 6.5 mg/kg). Virtually no work has been done to determine the plasma concentrations of bupropion and its three active metabolites in children and adolescents. Hence, it is unknown whether a limit of 6.5 mg per kg is also appropriate for children. No data exist as to whether children are more or less sensitive to bupropion in terms of seizure risk at the same drug concentration. Also, little is known about pharmacokinetic drug-drug interactions that could reduce the clearance of bupropion. For these reasons, cautious dosing is advised when prescribing bupropion for children on other medications that can reduce oxidative drug metabolism (see Chapter 3 and Chapter 7 for more details). 

No information in product labeling, but low plausibility of grapefruit juice interaction bupropion, doxazosin, gabapentin, lisinopril, risperidone, sertraline, and sibutramine. 

Maprotiline (bupropion) NET > SERT inhibition (amoxapine, maprotiline) t increased release of norepinephrine, 5-HT (mirtazapine) but no effect on 5-HT (bupropion) amoxapine and maprotiline resemble TCAs (mirtazapine) amoxapine and maprotiline rarely used bupropion) sedation and weight gain (mirtazepine) Interactions CYP2D6 inhibitor (bupropion)... 

Newer antidepressants (eg, fluoxetine, paroxetine, citalopram, venlafaxine) are mostly SSRIs and are generally safer than the tricyclic antidepressants and monoamine oxidase inhibitors, although they can cause seizures. Bupropion (not an SSRI) has caused seizures even in therapeutic doses. Some antidepressants have been associated with QT prolongation and torsade de pointes arrhythmia. SSRIs may interact with each other or especially with monoamine oxidase inhibitors to cause the serotonin syndrome, characterized by agitation, muscle hyperactivity, and hyperthermia (see Chapter 16). 

The therapeutic action of bupropion is mediated in part via direct interactions with serotonergic neurotransmission. 

Figure 2 List of precipitants evaluated with the substrates bupropion and efavirenz and which have shown more than 20% effect in in vivo inhibition. Display from the Metabolism and Transport Drug Interaction Database (http //www.druginteractioninfo...

McCollum DL, Greene JL, McGuire DK. Severe sinus bradycardia after initiation of bupropion therapy a probable drug-drug interaction with metoprolol. Cardiovasc Drugs Ther 2004 18 329-30. 

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