Amiodarone Fails to Improve Survival in Amitriptyline-Poisoned Mice

Objective. Amiodarone, a class III antidysrhythmic agent, blocks Na+, Ca2 +, and K+ channels as well as the β-adrenergic receptor. Despite increased use of amiodarone for wide-complex tachycardia, its efficacy in the treatment of dysrhythmias induced by tricyclic antidepressants has not been tested. We investigated the effect of amiodarone and amitriptyline in a mouse lethality model. Methods. The LD50 of amitriptyline obtained from reference sources was confirmed by giving 100 mg/kg to 40 mice by intraperitoneal (IP) injection. The safety of the treatment dose of amiodarone was confirmed by giving 50 mg/kg by IP injection to 10 mice. One hundred and nine mice were randomized to receive pretreatment with 50 mg/kg amiodarone (n = 55) or an equal volume of saline or water as a volume control (n = 54). Thirty minutes after pretreatment or control injection, the mice received amitriptyline, 100 mg/kg. Outcome was defined as death or survival 3 h after amitriptyline injection. Results. In our confirmation of t...