class IV antiarrhythmics

Last reviewed 01/2018

Class IV of the antiarrhythmics comprise the calcium channel blockers - verapamil but not the nifedipine group.

Verapamil should not be used for tachyarhythmias where the QRS complex is wide. Also it should not be used if there is atrial fibrillation with pre-excitation e.g. Wolff-Parkinson-White syndrome.