Ibogaine, an alkaloid from the African shrub Tabernanthe iboga, has psychoactive properties and is being studied as a potential treatment for opioid, stimulant, alcohol, and nicotine addiction. However, its complex interactions with many cellular targets raise significant safety concerns. Beyond neurotoxic effects, ibogaine may harm the heart: several sudden deaths after use have been reported, possibly due to cardiac arrhythmias. In one case, a woman experienced a severely prolonged QT interval and ventricular tachyarrhythmias after taking ibogaine.
Ibogaine, a plant alkaloid used in alternative medicine for addiction despite not being a licensed therapeutic, can disturb heart rhythm. At therapeutic concentrations it inhibits hERG potassium channels, which can cause life-threatening arrhythmias. This study examined ibogaine and its analog 18-methoxycoronaridine (18-MC) on cardiac ion channels using patch clamp techniques and computer simulations. Ibogaine reduced hERG currents at low micromolar concentrations (IC50, 4 µM) and, at higher concentrations, also inhibited sodium channels. 18-MC was less potent. In guinea-pig cardiomyocytes, ibogaine did not prolong the action potential at low concentrations; higher concentrations shortened it. Computer modeling suggested calcium channel blockade counteracts hERG inhibition's prolonging effect. Ibogaine is potentially proarrhythmic but may also have antiarrhythmic properties.