Factors associated with seizure development after bupropion overdose: a review of the toxicology investigators consortium.

Background: Bupropion is an aminoketone antidepressant. A major concern in bupropion toxicity is seizure activity, which can occur up to 24 h from ingestion. It is difficult to predict which patients will have seizures. The purpose of this study is to identify clinical features associate with seizure after bupropion overdose.
Methods: We searched the Toxicology Investigators Consortium registry for a cases of poisoning by bupropion between January 1, 2014 and January 1, 2017 in patients aged 13-65. Demographic variables and clinical features were compared between patients who did and did not experience a seizure and presented as unadjusted odds ratios (OR). Multivariable logistic regression was used to calculate adjusted odds ratios (aOR) between clinical features and seizures.
Results: There were 256 cases of bupropion overdose remaining after inclusion/exclusion criteria were applied. Clinical features associated with seizure were QTc >500 (OR = 3.4, 95% CI: 1.3-8.8, p  = 0.012), tachycardia ( p  > 140) (OR = 1.9, 95% CI: 1-3.561, p  = 0.05), and age 13-18 years (2.4, 95% CI: 1.3-4.3, p  = 0.005). The mean QTc value for patients experiencing a seizure was 482 ms ( N  = 95 IQR: 59 ms) versus 454 ms ( N  = 103, IQR: 43) in patients who did not experience seizure, however, it was not possible to identify a QTc cutoff with sensitivity or specificity to predict seizures.
Conclusion: Based on our analysis of data from the ToxIC registry, age (13-18), tachycardia ( p  > 140) and QTc >500 ms are associated with seizures in bupropion overdose; however, a specific QTc value may not be a useful predictor of seizures.