LONDON – The use of any form of acute antimigraine medication by patients with episodic migraine – be it single analgesics, combination analgesics, or triptans – exerted a protective effect against developing chronic migraine in a large, prospective, population-based study.
"This effect seems to be stronger for single analgesics and triptans than for combination analgesics," Dr. Zaza Katsarava observed in presenting findings from the German Headache Consortium Study at the European Headache and Migraine Trust International Congress.
Dr. Zaza Katsarava
He reported on 1,601 study participants with baseline episodic migraine – meaning migraine headaches on an average of not more than 14 days per month – who were prospectively followed for 2 years. None were on any form of prophylactic pain medication. The goal was to learn whether use of acute antimigraine medication to abort attacks predisposes patients over time to what has been termed "migraine chronification," or the conversion of episodic migraine into even more disabling and burdensome chronic headache, which in this study was defined as any type of headache occurring 15 or more days per month. There has been controversy regarding whether combination analgesics in particular might have such an unwanted effect.
"The purpose of our study is to learn whether general use of one of these classes of substances is associated with higher risk, in which case we would no longer advise their use in our patients," explained Dr. Katsarava, a neurologist at the University of Essen (Germany).
The answer proved reassuring. During 2 years of follow-up, 6.2% of patients with episodic migraine at baseline developed chronic headache. Compared with the 151 subjects who didn’t use any acute antimigraine medication, those who used single analgesics for that purpose had an adjusted 61% lower risk of progressing to chronic headache. Patients who used triptans had a 66% reduction in risk, and those who utilized combination analgesics had a 40% risk reduction, compared with no intake of acute antimigraine medication. This analysis was adjusted for age, sex, body mass index, education level, and baseline migraine frequency.
The protective effect was significantly greater with single analgesic medications as compared to combination analgesics, as reflected in a 35% lower associated relative risk of conversion to chronic headache.
Several audience members tried to argue that perhaps patients who take only single analgesics for acute antimigraine therapy have less severe migraine attacks than do those needing combination analgesics, and that it’s their lesser severity of migraine episodes rather than their use of single analgesics that renders them less likely to develop chronic headache. But Dr. Katsarava was having none of that.
"It’s the right thing to ask. It’s the argument that the pharmaceutical companies manufacturing combination analgesics make. But headache intensity has never been shown to be a risk factor for developing chronic headache; there is no scientific evidence for that. We know that what counts is the frequency of attacks, and we controlled for that," he countered.
Dr. Katsarava emphasized that this wasn’t a study focused on overuse of migraine abortive medications, which is already known to be an important contributor to headache chronification. Instead, the analysis included both normal users of acute antimigraine medications as prescribed and overusers.
The German Headache Consortium Study is funded by the German Federal Ministry of Education and Research. Dr. Katsarava reported serving as a consultant to Allergan and a paid speaker on behalf of that company as well as Merck Serono, Bayer Schering, Biogen, and St. Jude Medical.