Toxicology and applied pharmacology
December 1, 2013
Xaver Koenig, Michael Kovar, Lena Rubi et al.
46 citations
Ibogaine, a plant alkaloid used to treat drug addiction despite not being licensed, inhibits hERG potassium channels at low micromolar concentrations, which could disturb heart rhythm. At higher concentrations, it also reduces sodium and calcium currents. Its congener 18-MC blocks these ion channels with less potency. Unexpectedly, ibogaine did not prolong action potentials in guinea pig cardiomyocytes at low concentrations, and higher concentrations shortened them, likely because calcium channel inhibition counteracts hERG blockade effects. However, computer modeling of human ventricular cells suggested ibogaine does prolong the action potential in humans. The authors conclude therapeutic concentrations may prolong the QT interval, potentially leading to cardiac arrhythmias.
The International Journal of Neuropsychopharmacology
December 3, 2021
Benjamin Hackl, Hannes Todt, Helmut Kubista et al.
11 citations
Psilocybin, the hallucinogen in magic mushrooms, is being studied for psychiatric disorders, but safety concerns arose after reports of cardiac events and QT interval prolongation linked to its metabolite psilocin. Clinical concentrations of psilocin do not significantly inhibit the hERG potassium channel, a key risk factor for adverse cardiac effects. Therefore, hERG channel blockage by psilocin is not responsible for psilocybin-associated cardiotoxicity.
BMC Pharmacology
September 5, 2011
Michael Kovar, Xaver Koenig, Ágnes K. Mike et al.
5 citations
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.
BMC Pharmacology and Toxicology
September 1, 2012
Xaver Koenig, Michael Kovar, Lena Rubi et al.
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.