Pascual J., Mateos V., Gracia M. & Láinez J.M.
Services of Neurology, University Hospitals of Salamanca, Oviedo, Zaragoza and Valencia, Spain

Medication overuse headache in Spain

The aim of this study is to better define MOH epidemiology, using a personal interview and one month diary methodology. A total of 4855 unselected subjects were interviewed; prevalence of MOH was 1.4%. Overuse was more frequent in migraineurs (0.9%) than in subjects fulfilling criteria for chronic tension-type headache (0.4%) or new daily persistent headache (0.1%). These data concur with those of other epidemiological studies and show that MOH is a common disorder in the general population and a serious problem. Quality of life was also assessed: in the general population, MOH induces a remarkable decrease in all quality of life aspects studied by the Short Form-36 Health Survey (SF-36) questionnaire, with body pain and role physical being the most affected items. In neurological clinics in Spain headache is the most common reason for consultation (24–32% of new neurological visits), while migraine is the most frequent diagnosis in the clinics, accounting for around half of consultations due to headache. A clear female predominance has been the rule in all studies carried out in Spain: 89.9% in the general population and 94.6% in this study. The mean age of these subjects in the general population fulfilling MOH criteria was 56 years. The mean (subjective) age at onset of MOH was 38 years, whereas the mean age at onset of the primary episodic headache was 22 years. The distribution of overuse in this epidemiological study in Spain was as follows: 1.34.7% of patients overused simple analgesics; 2.22.2% of patients overused ergotamine-containing medications; 3.12.5% of patients overused opioids; 4.2.7% of patients overused triptans. The remaining 27.8% were overusing different combinations of these pharmacological groups. Patients suffering from MOH are difficult to treat. In 2006, the Headache Group of the Spanish Society of Neurology published the local guidelines for the treatment of these headache patients, including a combination of general measures and specific pharmacological treatments: I)promoting good communication between patient and physician; II)reassurance, excluding secondary headaches; III)identifying comorbid medical/psychiatric conditions; IV)recognizing the subtype of MOH (i.e. coming from migraine or tension-type headaches); V)concomitant behavioural intervention. When possible, pharmacological management should be planned on an out-patient basis. The general protocol should include:I)abrupt discontinuation of the offending symptomatic medications; II)specific treatment of detoxification; III)daily NSAIDs for about 15–30 days; IV)triptans only for moderate–severe headache only if they are not the overused drug and up to 2 days (two doses per day) per week; preventive treatment. Using this treatment protocol outlined above, about 50–60% of MOH patients move from a daily/almost-daily headache to an episodic one. Age, sex or socio-economic status did not influence prognosis. Patients who followed these recommendations had a significantly better prognosis. In-patient management is advised when the out-patient protocol has failed, in the presence of high depression scores, if the patient takes significant doses of tranquillizers, opioids of barbiturates.Even though combined analgesics (usually containing caffeine, ergotics or barbiturates) and opioids seem to be involved in the development of MOH, it is a general view that many patients with primary headache seem to be biologically predisposed to develop CDH regardless of analgesic overuse, which can be a consequence and not the reason for daily headache. There are many arguments supporting this contention, for example: the fact that CDH exists in children and adolescents, with no time for overuse to develop; the finding that almost three-quarters of those with daily/near-daily headache in the general population does not overuse analgesics; the experience that at least 40% of patients who are detoxified do not improve; the recent demonstration that preventatives work even in the presence of overuse. To conclude, the study also favours an active detection and treatment approach to these patients, whose condition can highly improve long-term in more than half of cases if managed adequately. (summary of the original article by H. Duyver)

Cephalalgia, 2008, 28, 1234-1236 (© Blackwell Publishing Ltd).