Tedisamil (Solvay)

Tedisamil, a potassium channel blocker (class III anti-arrhythmic agent)from Solvay, is in phase II trials for the potential treatment of atrial fibrillation [342434]. The drug had completed phase III trials for angina pectoris [342434], [177648], and although an NDA dossier for angina pectoris in refractory patients was ready for filing with the US FDA, Solvay has decided to pursue the broader indication of atrial fibrillation instead [342434]. Tedisamil is bradycardic without producing a negative inotropic effect. In a canine model of exercise-induced angina, myocardial function was maintained. In rat, rabbit, canine and simian hearts, there was a marked prolongation of action potential, due to tedisamil's modulating effects on potassium channels. Diastolic arterial pressure was not influenced [276934]. Tedisamil also rapidly terminated sustained atrial fibrillation and prevented its reinitiation in a canine model of the condition [315378]. The class III antiarrhythmic effect of tedisamil is related predominantly to the strong blocking effect of the drug on the rapid component of the delayed rectifier potassium current [334806].