Can Bupropion Cause Urinary Retention?
Bupropion is not typically associated with urinary retention and lacks the anticholinergic properties that commonly cause this adverse effect. In fact, one case report documented the opposite problem—diurnal enuresis (urinary incontinence)—rather than retention during bupropion treatment. 1
Mechanism and Pharmacology
Bupropion operates primarily through norepinephrine-dopamine reuptake inhibition with no appreciable anticholinergic activity. 2 This distinguishes it from many other antidepressants that do carry urinary retention risk through muscarinic receptor blockade.
Drugs that commonly cause urinary retention include those with anticholinergic activity (antipsychotics, tricyclic antidepressants, anticholinergic respiratory agents), opioids, alpha-adrenoceptor agonists, and benzodiazepines—but bupropion does not fall into these categories. 3
Clinical Evidence
A comprehensive review of drug-induced urinary retention identified anticholinergic antidepressants as culprits, but bupropion was not mentioned among the causative agents. 3
The most common adverse effects of bupropion include dry mouth, insomnia, headache, agitation, tremor, nausea, constipation, and vomiting—but urinary retention is not listed among typical side effects. 4, 2
One published case report documented diurnal enuresis (daytime urinary incontinence) in a 61-year-old man taking bupropion sustained-release, representing the opposite of retention. 1 This suggests bupropion may actually reduce urinary sphincter tone in rare cases rather than increase it.
Common Pitfalls
Do not confuse bupropion with tricyclic antidepressants or other anticholinergic agents that do cause urinary retention. The noradrenergic and dopaminergic mechanisms of bupropion do not impair bladder emptying through anticholinergic pathways. 2
Elderly patients taking multiple medications remain at higher risk for urinary retention from other concomitant drugs (alpha-blockers, anticholinergics, opioids), but bupropion itself is unlikely to be the causative agent. 3
Monitoring Recommendations
If urinary symptoms develop in a patient on bupropion, evaluate for other causative medications with known anticholinergic or alpha-adrenergic effects before attributing the problem to bupropion. 3
Monitor blood pressure and heart rate periodically (especially during the first 12 weeks), as these are the primary cardiovascular concerns with bupropion—not urinary retention. 4, 5
Screen for constipation, which is a documented common side effect of bupropion and may be confused with lower urinary tract symptoms. 4, 6