Major
Bupropion × citalopram
Other antidepressants (NDRI)×SSRI (selective serotonin reuptake inhibitor)
Mechanism
Additive seizure threshold reduction (both drugs do this). Weak additional serotonergic risk (bupropion has minimal serotonergic activity). Citalopram itself prolongs QT.
Symptoms
Seizures (especially with prior epilepsy or eating disorders), QT prolongation on ECG, dizziness. Serotonin syndrome when other serotonergics are added.
Management
The combination is used for antidepressant augmentation (bupropion added to SSRI). Cap citalopram at 20 mg, bupropion at 300 mg/day. Avoid in prior epilepsy or eating disorders.