Last reviewed 2026-04-20 · How we verify

bupropion immediate release (IR) (bupropion-immediate-release-ir)

Bupropion immediate release IR is a marketed drug by Pfizer Inc. It is used for Major Depressive Disorder MDD, Seasonal Affective Disorder SAD, and Smoking Cessation. The exact mechanism of action is not fully understood, but it is believed to affect neurotransmitter levels in the brain. Bupropion IR has a unique profile compared to other antidepressants, with a faster onset of action and a lower risk of weight gain. This makes it a valuable option for patients who have not responded to other treatments. However, its use is not without controversy, and more research is needed to fully understand its effects. Overall, bupropion IR is a significant player in the market for antidepressants and smoking cessation.

At a glance

Approved indications

• Major Depressive Disorder (MDD)
• Seasonal Affective Disorder (SAD)
• Smoking Cessation

Common side effects

No common side effects on file.

Drug interactions

• Alcohol
• Cimetidine
• Citalopram
• Clonopin
• Diazepam
• Doxepin
• Fluoxetine
• Haloperidol
• Hydrocodone
• Imipramine
• Ketamine
• Levodopa

Key clinical trials

• Pharmacokinetic Drug-drug Interaction Study of Encorafenib and Binimetinib on Probe Drugs in Patients With BRAF V600-mutant Melanoma or Other Advanced Solid Tumors (PHASE1)
• Pharmacokinetic Study of Bupropion Hydrochloride Products With Different Release Patterns (PHASE4)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• bupropion immediate release (IR) CI brief — competitive landscape report
• bupropion immediate release (IR) updates RSS · CI watch RSS
• Pfizer portfolio CI