Bupropion-Associated QRS Prolongation Unresponsive to Sodium Bicarbonate Therapy

Abstract

We describe a case of bupropion-associated QRS prolongation that was unresponsive to intravenous bolus therapy of sodium bicarbonate. Bupropion may cause seizures and conduction delays similar to tricyclic antidepressants in the overdose setting by an unknown mechanism.

QRS widening and QT prolongation under bupropion: a unique cardiac electrophysiological profile

“…In the present study, we have shown that bupropion is a weak I Kr blocker, with an estimated IC 50 on HERG tail currents of ∼34 μ m , a concentration well above the therapeutic range (0.05–0.1 mg/L:0.18–0.36 μ m ) [1], but nonetheless reachable in cases of overdosage (20 mg/L:72 μ m ) [21]. This is consistent with the fact that most cases of bupropion‐related QT interval prolongation have been reported in a context of drug overdosage [1,5,6,8–13,18]. We have also shown small and nonsignificant block of I Ks by bupropion 10 μ m , suggesting that bupropion‐related QT prolongation is, as for nearly all other QT‐prolonging drugs [32], mostly attributed to I Kr block.…”

“…Indeed, sinus tachycardia is the most common cardiovascular side effect associated with bupropion, mostly during overdosage [1–17]. Nonetheless, a number of bupropion‐related QTc interval prolongation have been reported [1,5,6,8–13,18]. Again, most of these occurred during overdosage, and there has been no report of bupropion‐induced torsades de pointes.…”

Lipid Emulsion as Rescue Therapy in Lamotrigine Overdose

“…QRS prolongation unresponsive to bicarbonate therapy has been previously reported with bupropion, another sodium channel blocker (10,11). In our report, as left bundle branch block was observed with a sinus rhythm of 88, it cannot be attributed to tachycardia-induced myocardial ischemia.…”

A Literature Review of the Use of Sodium Bicarbonate for the Treatment of QRS Widening

“…Interestingly, the QRS prolongation associated with bupropion does not appear to be responsive to sodium bicarbonate therapy as described in several case reports [72][73][74]. With regards to a possible mechanism for this finding, Caillier et al used patch clamp techniques to determine that bupropion did not significantly change sodium current amplitude or steady-state activation/inactivation.…”

“…Case report [71] In vitro data (references) Bupropion Case reports [72][73][74] Guinea pig hearts, rat neonatal myocytes, rat atria, canine ventricular tissue, crayfish axons [75,76] Human embryonic kidney cells [75] Propranolol Canine study [77] …”