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Non-Dihydropyridine Calcium Channel Blocker

Verapamil

Brand names: Securon, Univer

Used in: Atrial Fibrillation

Verapamil is a rate-limiting (non-dihydropyridine) calcium-channel blocker used for angina, hypertension and certain supraventricular arrhythmias.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION The dose of verapamil must be individualized by titration. The usefulness and safety of dosages exceeding 480 mg/day have not been established; therefore, this daily dosage should not be exceeded. Since the half-life of verapamil increases during chronic dosing, maximum response may be delayed. Angina: Clinical trials show that the usual dose is 80 mg to 120 mg three times a day. However, 40 mg three times a day may be warranted in patients who may have an increased response to verapamil (e.g., decreased hepatic function, elderly, etc.). Upward titration should be based on therapeutic efficacy and safety evaluated approximately eight hours after dosing. Dosage may …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-05-22. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Clinical monograph

How it works

It blocks L-type calcium channels, slowing conduction through the atrioventricular node, reducing heart rate and contractility, and causing vasodilatation.

Prescribing in practice

  • Do not combine with a beta-blocker because of the risk of severe bradycardia, heart block and asystole.
  • It is contraindicated in significant left ventricular dysfunction and heart failure as it is strongly negatively inotropic.
  • It raises plasma digoxin levels and commonly causes constipation.

Monitoring

Monitor heart rate, blood pressure and for signs of heart failure; review concurrent digoxin and other rate-limiting drugs.

Counselling the patient

  • Report a slow pulse, dizziness, fainting or breathlessness.
  • Constipation is common — maintain fluids and fibre, and seek advice if troublesome.

Evidence & guidelines

A long-established treatment for angina, hypertension and rate control in supraventricular arrhythmias in UK practice.

Reference: ESC AF Guidelines 2020; ACC/AHA Guideline on Atrial Fibrillation; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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