A double-blind crossover study comparing betahistine and cinnarizine in the treatment of recurrent vertigo in patients in general practice.

A double-blind crossover study was carried out in general practice in 88 patients with peripheral vertigo of unknown origin to compare the efficacy and tolerance of 12 mg betahistine dihydrochloride and 15 mg cinnarizine. Patients were allocated at random to receive 2 tablets 3-times daily of one or other drug for 3 consecutive months before being crossed over to the alternative medication for a further 3 months. Severity of symptoms was assessed at 4-week intervals using the Clinical Global Impression scale and patients kept a record in a daily diary of the frequency and duration of attacks. Details were also recorded of any side-effects reported. The results were analyzed for 46 patients who completed the 6-month study period. Both drugs were shown to be equally effective in reducing the duration and severity of symptoms. Significantly fewer attacks of vertigo, however, occurred during betahistine therapy. Side-effects were the most common reason for dropping out whilst on cinnarizine (9 patients) and were complained of by 38 patients during the study (16 only when on betahistine, 19 only on cinnarizine, 3 whilst on both drugs). The most frequently reported were drowsiness or lethargy affecting 16 patients on cinnarizine and 7 on betahistine.