Treatment
Preventive treatments for cluster headache
Verapamil is the first choice preventive treatment for most New Zealand patients, but it is not the only option. This page covers the other preventive treatments available when verapamil is not sufficient or not tolerated.
Most of the treatments on this page are more complex to manage than verapamil and are typically prescribed and monitored by a neurologist rather than a GP alone. If your cluster headache is not controlled on verapamil, ask your GP for a referral to a neurologist with an interest in headache.
Why prevention matters
During a cluster period, most patients experience one to three attacks per day, every day, for weeks or months. Acute treatments (oxygen and sumatriptan) are essential, but they treat attacks after they start. Preventive treatment aims to reduce the number and severity of attacks so there are fewer attacks to treat, and to shorten the overall cluster period.
For chronic cluster headache patients, prevention is not about shortening a period - it is about making daily life manageable.
Verapamil (Isoptin, Isoptin SR) is the first-choice preventive for most patients and is funded by PHARMAC in New Zealand as a long-established generic medicine, available as immediate-release and slow-release tablets. See the dedicated verapamil page for dosing, ECG monitoring and titration. This page covers what to consider when verapamil is not sufficient or not tolerated.
Short-term bridging and transitional treatment
Short-term bridging therapy can provide rapid relief while a longer-term preventive like verapamil takes effect. This commonly involves oral corticosteroids such as prednisone or prednisolone, or a specialist-delivered greater occipital nerve block.
These treatments are not long-term preventives because repeated or prolonged steroid exposure carries significant risks. We cover this separately on the transitional bridging therapy page.
Second-line preventive options
Lithium
Lithium carbonate has been used for cluster headache prevention for decades, particularly for chronic cluster headache where it may have an advantage over verapamil. It requires regular blood tests to monitor lithium levels and kidney and thyroid function. Lithium has a narrow therapeutic window - the effective dose is close to the toxic dose - so careful monitoring is essential. It is typically managed by a neurologist or physician with experience in its use.
In New Zealand, lithium is available and funded by PHARMAC (verify current status with your prescriber).
Topiramate
Topiramate (an anticonvulsant also used for migraine prevention) has some evidence for cluster headache prevention. It is generally less effective than verapamil but may be useful when verapamil is contraindicated or not tolerated. Common side effects include cognitive slowing ("brain fog"), weight loss, tingling in extremities and kidney stones.
Topiramate can harm an unborn baby, and effective contraception is advised throughout treatment. If you could become pregnant, are pregnant, or are planning a pregnancy, talk to your doctor before starting or stopping it - do not stop a prescribed medicine on your own. See Medsafe's topiramate and pregnancy advice for full detail.
Melatonin
Melatonin 10mg at night has some evidence as an add-on preventive, possibly because cluster headache has a circadian component and melatonin helps regulate circadian rhythms. Evidence is modest but the safety profile is excellent and it is available without prescription in New Zealand.
Sodium valproate
Evidence for sodium valproate in cluster headache is limited and conflicting. An open-label trial (Hering & Kuritzky, Cephalalgia, 1989) suggested benefit, but the only double-blind, placebo-controlled trial - two weeks of treatment at 1000-2000 mg/day in 96 patients - found no significant difference from placebo (50% of the valproate group and 62% of the placebo group improved; the authors attributed the high placebo response to spontaneous remission of the cluster period) (El Amrani, Massiou & Bousser, Cephalalgia, 2002). The 2023 European Academy of Neurology guideline lists it as a consensus-based third-choice option once other preventives have failed, at a typical dose of 5-20 mg/kg/day (around 1200 mg/day in adults).
Valproate is highly teratogenic. Medsafe's New Zealand data sheet states it should not be used in female children or women of childbearing potential unless other treatments are ineffective or not tolerated, and sets out specific pregnancy-prevention requirements where it is used regardless - including assessing pregnancy potential, counselling on the risks, pregnancy testing before and during treatment, and ensuring effective contraception without interruption throughout treatment. If you could become pregnant, are pregnant, or are planning a pregnancy, talk to your doctor before starting or stopping it - do not stop a prescribed medicine on your own.
CGRP monoclonal antibodies
Galcanezumab (Emgality) is a CGRP (calcitonin gene-related peptide) monoclonal antibody that has demonstrated efficacy in episodic cluster headache in clinical trials, where it was studied as a 300 mg monthly injection - a higher dose than the one used for migraine. Its efficacy has been shown only in episodic cluster headache; the trial in chronic cluster headache was negative.
The 300 mg cluster headache dose is not available in New Zealand at all. Medsafe's New Zealand data sheet for Emgality lists only the 120 mg prefilled pen and prefilled syringe, dosed as a 240 mg loading dose followed by 120 mg monthly, and its approved indication here is migraine prophylaxis, not cluster headache. Even a private prescription cannot currently obtain the 300 mg dose used in the cluster headache trials. Galcanezumab is not funded by PHARMAC for cluster headache in New Zealand. This is an area we are monitoring and advocating on.
Funding decisions are made by PHARMAC and can change. Always verify current funding with your prescriber or check the PHARMAC funded medicines schedule.
Greater occipital nerve block
A greater occipital nerve (GON) block involves injecting a local anaesthetic with or without corticosteroid around the greater occipital nerve at the back of the head. It can provide rapid temporary relief from cluster periods and is sometimes used as a bridging treatment or to provide a break from attacks while other preventives take effect. GON blocks are performed by neurologists or pain specialists and are available at some New Zealand centres.
What if nothing is working?
A minority of patients have refractory cluster headache that does not respond adequately to standard preventive treatments. In these cases, specialist input from a tertiary headache service is important. Options being investigated or used in specialist centres internationally include sphenopalatine ganglion stimulation and deep brain stimulation. SPG stimulator insertions have largely stopped since before COVID after the original device company’s collapse, and these options are not widely available in New Zealand.
If you feel your treatment is inadequate, push for a neurologist referral. You are not expected to manage this condition without specialist input.
Return to the treatment overview for a full picture, or read about alternative and emerging treatments including the current state of evidence on psilocybin and other options being explored in the cluster headache community.