Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Bepridil
See also Calcium channel blockers
General information
Bepridil is an antidysrhythmic drug with unusual pharmacological properties in that it belongs to both class I and class IV. In other words, it blocks both the fast inward sodium current and the slow outward calcium current in excitable cardiac cells [ , ]. It was withdrawn because of its serious prodysrhythmic effects.
Bepridil has been the subject of a brief general review [ ] and its pharmacokinetics have been specifically reviewed [ ]. Although it is highly protein-bound, bepridil does not take part in protein-binding displacement interactions [ ].
The main adverse effect of bepridil is torsade de pointes due to QT interval prolongation. After intravenous infusion bepridil can cause local reactions [ ] and phlebothrombosis [ ]. Other minor adverse effects that have been reported include urticaria [ ], gastrointestinal disturbances (especially diarrhea) [ , ], and dizziness [ ]. Hepatic enzymes can rise [ , ].
Drug studies
Comparative studies
In a randomized study in 61 patients with symptomatic paroxysmal atrial fibrillation, bepridil 200 mg/day (n = 23) was compared with flecainide 100–200 mg/day or pilsicainide 75–150 mg/day (n = 38) [ ]. Both bepridil and the class Ic drugs effectively prevented paroxysmal atrial fibrillation (15/23 versus 24/38). In those who took the class Ic drugs, the f-f interval on the surface electrocardiogram during atrial fibrillation before treatment was significantly longer in responders (114 ms) than in non-responders (68 ms). In contrast, in those who took bepridil the f-f interval was significantly shorter in responders (85 ms) than in non-responders (152 ms). In non-responders the class Ic drugs prolonged the f-f interval from 78 ms to 128 ms whereas bepridil had no significant effect (109 versus 135 ms). Although bepridil has been primarily classified as a drug with class I and class IV properties, the authors suggested that these results marked it as acting primarily by a class III mechanism in paroxysmal atrial fibrillation. This is consistent with reports that bepridil inhibits a slow component of the cardiac delayed rectifier potassium current IKs in HEK293 cells [ ].
You're Reading a Preview
Become a Clinical Tree membership for Full access and enjoy Unlimited articles
If you are a member. Log in here