Pharmacology Notes

Verapamil and diltiazem are class IV antiarrhythmic drugs. Verapamil is more commonly used as an antiarrhythmic than diltiazem. It reduces the slow calcium-dependent action potential, particularly important in the atrioventricular node, and is capable of reducing ventricular response rates to supraventricular arrhythmias as well as interrupting atrioventricular nodal re-entry circuits. It can also potentially cause various degrees of heart block.