Study objective: To determine the frequency of adverse effects, clinical outcomes, and possible dose-response relationships associated with inadvertent extra doses of bupropion.
Design: Retrospective review.
Data source: Toxic Exposure Surveillance System of the American Association of Poison Control Centers.
Subjects: Four hundred seventy-six patients who inadvertently took extra doses of bupropion.
Measurements and main results: Cases in the surveillance database were evaluated based on documented doses, treatment sites, symptoms, and clinical outcomes by using standard data-field definitions. Over a 4-year period from 2000-2003, more women than men unintentionally took extra doses of bupropion (354 [74.4%] vs 122 [25.6%]). Ingested doses ranged from 75-1500 mg with a median and mode of 300 mg. Of the 476 patients, only 127 (26.7%) had to be evaluated in an emergency department. Seizures were reported in four patients (0.8%), and one developed status epilepticus. Other prominent adverse effects were agitation (39 patients [8.2%]), dizziness (35 [7.4%]), tremor (34 [7.1%]), nausea and/or vomiting (32 [6.7%]), drowsiness (29 [6.1%]), tachycardia (26 [5.5%]), and hallucination (2 [0.4%]). Clinical outcomes were no effect (293 patients [61.6%]), minor effect (132 [27.7%]), moderate effect (49 [10.3%]), or major effect (2 [0.4%]). Overall, 183 patients (38.4%) had at least one adverse effect. Doses were higher in patients with adverse effects than in those with no effect (p = 0.045). Doses were slightly higher in those with moderate or major outcomes than in others, but the difference was not significant (p = 0.083).
Conclusion: Adverse effects were common with extra doses of bupropion, and clinically significant effects occurred in approximately 10% of patients. Seizures were present twice as often as reported with therapeutic dosing. Extra doses of bupropion appear to increase the risk of adverse effects. Patients should be educated about these risks to minimize them.