The findings from a large analysis of clinical trial data suggest that the use of blood pressure (BP)-lowering medications can prevent a significant number of headaches. Agents from different classes of BP medicines can have this effect. Yet, according to Malcolm Law, FRCP, of London Queen Mary's School of Medicine and Dentistry, these findings have not supported a link between high BP and headaches.
The study, reported in Circulation (October 11, 2005), involved data from 94 trials that looked at the 4 main BP-lowering drug classesthiazides, beta-blockers, angiotensin II receptor antagonists, and angiotensin-converting enzyme inhibitors. A total of 17,641 patients received one of these agents, and 6603 received a placebo. Overall, 12.4% of those taking the placebo reported an incidence of headaches, compared with 8% of those taking an agent.
The study authors estimated that ~1 in 30 patients taking a BP-lowering agent benefited by having a headache prevented. All 4 drug classes appeared to provide a substantial reduction in headache prevalence. It is still a mystery whether high BP actually causes headaches, however, Dr. Law said.