Incidence of seizures during treatment with tricyclic antidepressant drugs and bupropion.

The incidence of convulsions in patients receiving tricyclic antidepressants or bupropion was reviewed. For both types of drug, the risk of a seizure was dose-dependent and was higher in patients with predisposing factors, e.g., a history of seizures. Patients without a predisposing factor had a convulsion incidence of approximately 0.6%-0.9% (6-9/1,000 patients) when receiving imipramine at doses of greater than 200 mg/day or bupropion at doses greater than 450 mg/day. At lower doses, the frequency of seizures dropped to about 1/1,000 (or less) for imipramine and bupropion. Thus, the risk of a seizure in patients receiving equally therapeutic doses of imipramine and bupropion appears to be comparable.