verapamil

verapamil is evaluated for the following indications with varying evidence strength: Non-valvular atrial fibrillation (evidence tier A), Vasospastic (Prinzmetal) angina (evidence tier A), Migraine prophylaxis (evidence tier B). See the full indication matrix with dosing and citations above on this page.

Common side effects of verapamil (≥ 1 in 100): Constipation (most frequent adverse event, up to 25 percent of patients), Bradycardia, PR-interval prolongation, Dizziness, Peripheral edema, Facial flushing, headache. See the Safety section for uncommon and serious reactions.

FDA category C. FDA category C. Used in pregnancy for supraventricular arrhythmias and hypertrophic cardiomyopathy when benefit outweighs risk. Symptomatic bradycardia and hypotension in the fetus and newborn are possible. Decision is shared with the obstetrician and cardiologist.

Verapamil passes into breast milk at concentrations near 60 percent of maternal plasma. LactMed lists it as compatible with breastfeeding with infant monitoring: lethargy, poor feeding, or symptomatic bradycardia warrant evaluation.

verapamil is contraindicated in: Systolic heart failure (LVEF below 40 percent); Second- and third-degree AV block without a pacemaker; Sick sinus syndrome without a pacemaker; WPW syndrome with atrial fibrillation; Cardiogenic shock. Full list in the Safety section.

the combination is forbidden in cardiology – additive sinus and AV node suppression can produce complete block and asystole.

splitting destroys the release matrix and delivers the full dose at once with severe bradycardia risk. Adjust dose by switching to a different strength, not by splitting.

verapamil causes peripheral edema less often than amlodipine, but in 5–10 percent of patients it appears, driven by precapillary vasodilation rather than fluid retention.