Nondihydropyridine calcium channel blockers for rate control of atrial fibrillation

If beta blockers are contraindicated, not tolerated or do not control ventricular rate in patients with atrial fibrillation, diltiazem or verapamil (nondihydropyridine calcium channel blockers) can be used to attain and maintain long-term rate control. Avoid diltiazem or verapamil in patients with a left ventricular ejection fraction of 40% or less because these drugs have negative inotropic effects.

If diltiazem or verapamil are considered appropriate, useHindricks, 2021:

1diltiazem immediate-release 60 mg orally, 2 or 3 times daily; titrate to response and tolerability1. Maximum dose 360 mg daily in divided doses diltiazem diltiazem diltiazem

OR

1verapamil immediate-release 40 mg orally, twice daily, increasing if required up to 80 mg orally, 2 or 3 times daily; titrate to response and tolerability. Maximum dose 480 mg daily in divided doses. verapamil verapamil verapamil

The immediate-release formulations allow for rapid dose titration and for short duration of effect.

Once the appropriate dose has been established, consider switching to the modified-release formulation of diltiazem or verapamil. If the risk of adverse effects is low (eg younger patients) consider using the modified-release formulation as initial therapy for rate control. UseHindricks, 2021:

1diltiazem modified-release 180 mg orally, daily, increasing if required up to 360 mg daily1 diltiazem diltiazem diltiazem

OR

1verapamil modified-release 180 mg orally, daily, increasing if required up to 480 mg daily. verapamil verapamil verapamil

1 At the time of writing, diltiazem is not approved by the Australian Therapeutic Goods Administration (TGA) for rate control in atrial fibrillation. See the TGA website for current information.Return