Headache management: pharmacological approaches

Background

Headache is listed among the WHO's major causes of disability with a global prevalence of 47% (symptoms occurring at least once in the past year). It is the commonest neurological syndrome presenting to primary care with 3% of adults consulting a general practitioner for headache each year. 1 Women are disproportionately affected (3:1) and its higher prevalence among those of working age adds to the socioeconomic burden with loss of productivity, estimated at £2.25 billion per year in the UK. 2

In neurological practice, headache accounts for 25% of new referrals and yet a large proportion of these patients feel dissatisfied even if they make it to the neurology clinic, partly due to a reported lack of interest in the disorder by the reviewing neurologist. 2 Most patients with headache have migraine, and when this diagnosis is made it is usually correct (98%). 3 However, a quarter of patients with migraine have as their diagnosis missed. Furthermore, of those identified as a non-migrainous primary headache, 82% actually have migraine or probable migraine. 3

Neurologists consequently see a lot of patients with headache and the condition is very disabling for individuals. A diagnosis, empathy and effective treatment make a huge difference to the patient and can be very rewarding for the clinician. The purpose of this article, the first of two linked articles, is to provide an up-to-date overview of the pharmacological management of common headache disorders (as well as a limited number of non-pharmaceutical strategies).

The common primary headache disorders

In European populations, the annual sex-adjusted prevalence for tension-type headache is 35%, for migraine is 38%, but for cluster headache is only 0.15%. 4 5 These three together comprise the most prevalent primary headache disorders. The remaining primary headache diagnoses-all relatively rare-include paroxysmal hemicrania, hemicrania continua, short-lasting unilateral neuralgiform headache attacks, hypnic headache and new daily persistent headache. Table 1 outlines the features that help to distinguish these disorders.

Table 1

Headache	Tension-type headache	Migraine	Trigeminal autonomic cephalalgias	Trigeminal neuralgia
Cluster headache	Paroxysmal hemicrania	Hemicrania continua	SUNCT/SUNA
Sex (M:F)	4:5	3:1	5:1	1:1	1:2	3:2	2:3
Duration	30 min to 7 days (episodic)	4-72 h	15-180 min	2-30 min	Continuous headache	1-600 s	1-120 s
Frequency	Episodic or chronic (variable from rare to daily)