Verapamil — Preventative Treatment Overview

Verapamil is a calcium-channel blocker commonly used for heart rhythm problems and high blood pressure.
In headache medicine, it is considered the first-line preventative treatment for cluster headache, and is the most commonly prescribed long-term preventative for both episodic (ECH) and chronic cluster headache (CCH).

It is often the starting point for most patients once a cycle begins or chronic symptoms develop.

Transitional therapy: short oral corticosteroid taper (e.g., prednisone) or greater occipital nerve block to suppress a bout while Verapamilk takes effect.


What Verapamil Is

  • Originally developed for cardiovascular conditions

  • Used safely for decades

  • Strong evidence for reducing cluster headache attack frequency

  • The most widely studied CH preventative in the world

Because verapamil influences nerve transmission, blood vessel stability, and certain hypothalamus-related rhythms, it has become the gold standard for managing cluster headaches.


How Verapamil Works

Verapamil blocks calcium channels in blood vessels and certain nerve tissues.
This leads to:

  • Stabilisation of nerve firing in the trigeminal system

  • Reduced release of neuropeptides involved in CH (e.g., CGRP)

  • Calming of pain-transmission circuits

  • Dampening of hypothalamic/autonomic activity that drives cluster attacks

Over time, this reduces the intensity and frequency of attacks.


Evidence for Use in Cluster Headache

Verapamil has the strongest evidence base of any preventative medication for cluster headache.

Clinical data and decades of neurology practice show:

  • Many patients respond within 1–2 weeks

  • Attack frequency may drop dramatically

  • Some patients achieve complete remission

  • Works for both episodic and chronic CH

  • Often used with a short prednisone taper at the beginning of treatment to achieve earlier control while verapamil builds up

Neurologists worldwide consider it the backbone of CH prevention.


Typical Dosing (Neurologist-guided only)

Cluster headache requires higher doses of verapamil than blood pressure treatment.

Typical CH approach:

  • Start at 80 mg 3x daily OR 120 mg extended-release once or twice daily

  • Increase every 7–14 days depending on response

  • Common effective range: 240–480 mg/day

  • Some chronic CH patients require up to 720–960 mg/day under specialist supervision

Because verapamil affects heart conduction, dose increases must be slow and monitored.


ECG Monitoring — Essential

Verapamil can slow electrical signals in the heart.
For this reason, regular ECGs (electrocardiograms) are required:

  • Before starting

  • At each dose increase

  • Periodically while on a stable high dose

This ensures safety and helps identify rare but important changes like heart block or prolonged PR interval.

This is one reason cluster headache specialists — not GPs — usually manage verapamil treatment.


Common Side Effects

Most side effects are dose-dependent and manageable.

Common effects include:

  • Constipation

  • Low blood pressure

  • Fatigue

  • Light-headedness

  • Swollen ankles

  • Slow pulse

These often improve with dose adjustments or by switching from extended-release to immediate-release formulations.

Less common but important risks include:

  • Heart conduction issues (usually detected by ECG)

  • Worsening of heart failure

  • Severe constipation

  • Interactions with other heart medications


Who Should Avoid Verapamil

Verapamil may not be suitable for people with:

  • Certain heart rhythm disorders

  • Heart failure

  • Very low blood pressure

  • Slow baseline heart rate

  • History of heart block

  • Interaction with other medications (e.g., beta blockers, digoxin)

A neurologist or cardiologist will determine suitability.


Verapamil in Episodic vs Chronic CH

Episodic CH:

  • Often very effective

  • Used during the active cycle, then tapered off when cycle ends

  • Usually combined initially with a short steroid taper

Chronic CH:

  • Often requires higher doses

  • Sometimes used in combination with lithium or topiramate

  • Long-term ECG monitoring is essential


Summary

Verapamil is the gold-standard preventative medication for cluster headache. It reduces nerve excitability, dampens trigeminal pain pathways, and stabilises the autonomic system involved in CH.
Most patients see meaningful improvement, and many require only verapamil for long-term control.

Best suited for:
Most cluster headache patients, especially those with episodic CH.

Key considerations:
Requires structured dose increases and ECG monitoring to ensure safe use at effective doses.