Despite the considerable limitations of an open, non-masked trial, particularly in Menire's disease (MD), a higher dosage of betahistine-dihydrochloride and a long-term treatment seems to be more effective than a low dosage and short-term treatment. Objective.
To evaluate the prophylactic effects of a low versus high dosage long-term treatment with betahistine-dihydrochloride on the number of attacks in MD. Patients and methods.
We performed an open, non-masked trial, in which patients with MD received either a low dosage of betahistine-dihydrochloride (16 or 24 mg tid) or a higher dosage of 48 mg tid for at least 12 months. The outcome measure was the number of attacks per month during a 3-month period.
Non-parametric tests and a random effects model were used for statistical analysis. Results.
A total of 112 patients were included in the analysis: 50 received betahistine-dihydrochloride in a low dosage (16 mg tid, n=21, 24 mg, n=29) and 62 received 48 mg tid. Follow-up examination every 3 months showed that the number of attacks per month decreased in both groups over time.
For instance, after 12 months the mean (median) number of attacks dropped from 7.6 (4.5) to 4.4 (2.0) (p < 0.0001) in the low-dosage group, and from 8.8 (5.5) to 1.0 (0.0) (p < 0.0001) in the high dosage group. The number of attacks after 12 months was significantly lower in the high dosage group than in the low dosage group (p(12M)=0.0002).
The treatment was well tolerated in both groups.