Treatment
Verapamil for cluster headache prevention in New Zealand
Verapamil is the recommended first-line preventive treatment for cluster headache in New Zealand. It does not stop individual attacks - it reduces the frequency of attacks during a cluster period or, in chronic cases, helps suppress ongoing attacks. It is funded by PHARMAC.
What verapamil does
Verapamil is a calcium channel blocker, primarily used to treat high blood pressure and heart rhythm disorders. In cluster headache, it reduces the frequency, severity and duration of attacks when taken daily throughout a cluster period. For chronic cluster headache patients, it is taken continuously as an ongoing preventive.
Verapamil does not work immediately. It typically takes one to two weeks at an adequate dose to take effect. This is why it is always used alongside acute treatments (oxygen and sumatriptan) - verapamil gives the preventive background, acute treatments handle individual attacks while the verapamil builds up.
PHARMAC funding in New Zealand
Verapamil is funded by PHARMAC for cluster headache prevention.
As of the time of writing, verapamil tablets are funded by PHARMAC. You pay only the standard prescription co-payment. There is no prior approval required for cluster headache - your GP can prescribe it directly.
Dosing and titration
The typical starting dose of verapamil for cluster headache is 80mg three times daily (240mg per day). This is lower than the doses used in clinical trials and in specialist practice, but is a common starting point in primary care. The dose is then titrated upward based on response and tolerability.
In neurologist-led care, higher doses are used - commonly up to 480–720 mg/day, and occasionally higher under specialist supervision - for adequate control. Higher doses are more likely to be managed by a neurologist than a GP.
Titration in practice
- Start at 80mg three times daily (240mg/day)
- Increase by 80mg at a pace your clinician sets if attacks continue - this can range from every few days to every couple of weeks depending on how closely you can be monitored
- ECG monitoring is required, on a schedule your clinician sets (see below)
- Continue at the effective dose throughout the cluster period
- For episodic cluster headache: reduce the dose slowly at the end of the cluster period - medicines that are increased gradually should usually be reduced gradually
- For chronic cluster headache: continue indefinitely at the effective dose, with regular review
ECG monitoring - why it matters
Important: verapamil can be associated with changes in heart rhythm. ECG monitoring is recommended.
Verapamil can slow the heartbeat or affect the way the electrical signal travels through the heart. This can happen at any dose, and it can also appear after you have been on the same dose for a while.
For that reason ECG monitoring is required - before you start, and from time to time while you are taking it. How often is a decision for your clinician, not something to self-adjust.
If your GP has not mentioned ECG monitoring, raise it with them. It is an important part of using this medicine safely.
Common side effects
Verapamil is generally well tolerated at lower doses. Common side effects include:
- Constipation - the most common side effect. Increase dietary fibre and fluid intake.
- Fatigue or tiredness
- Dizziness, particularly on standing (postural hypotension)
- Ankle swelling
- Slow heart rate (bradycardia)
- Nausea
Most side effects are dose-related and improve if the dose is reduced. If you experience chest pain, significant shortness of breath, or a very slow or irregular pulse, seek medical attention promptly.
Who should not take verapamil
Verapamil is not appropriate for everyone. Tell your GP if you have:
- Existing heart block or sick sinus syndrome
- Severe heart failure
- Very low blood pressure
- Wolff-Parkinson-White syndrome
Verapamil interacts with a number of other medications including beta-blockers, digoxin, statins and some antibiotics. Provide your GP with a full list of your current medications before starting verapamil.
What to expect in the first few weeks
When you start verapamil, you will still have attacks - verapamil takes time to work. This is normal and expected. Do not stop taking verapamil because you are still getting attacks in the first week or two. Continue using your acute treatments (oxygen and sumatriptan) for each attack while the verapamil takes effect.
If your attacks have not reduced after two to three weeks at an adequate dose, the dose may need to be increased. Discuss this with your GP and consider asking for a neurologist referral if you are not getting adequate relief.
Verapamil is straightforward to start at the GP level, but dose titration above 360mg per day, managing side effects and evaluating whether additional preventive treatment is needed is best done with neurologist input. If your attacks are not controlled on standard doses, ask your GP for a referral. You should not have to keep suffering while waiting for the medication to "work" at a dose that may be too low. See our page on other preventive treatments for options when verapamil is not sufficient.