Treatment of vertigo due to acute unilateral vestibular loss with a fixed combination of cinnarizine and dimenhydrinate: a double-blind, randomized, parallel-group clinical study.

BACKGROUND: Acute unilateral vestibular loss is a balance disorder that is accompanied by vertigo symptoms and concomitant vegetative symptoms, including nausea and vomiting. Patients are frequently confined to bed rest but may continue to experience vertigo symptoms. A well-established antivertiginous therapy consisting of cinnarizine and dimenhydrinate at low doses may offer rapid relief of acute vertigo symptoms due to acute vestibular loss, without inhibiting physiological compensation processes.

OBJECTIVE: The purpose of this study was to compare the clinical efficacy and tolerability of a fixed combination of cinnarizine 20 mg and dimenhydrinate 40 mg versus monotherapy with its respective components in the treatment of acute vertigo symptoms due to acute unilateral vestibular loss.

METHODS: In this prospective, single-center, randomized, double-blind, parallel-group clinical study, 50 patients with acute vestibular vertigo were randomly assigned to receive 4 weeks of treatment (1 tablet 3 times daily) with a fixed combination of 20 mg cinnarizine and 40 mg dimenhydrinate, 20 mg cinnarizine alone, or 40 mg dimenhydrinate alone. All patients received a 15% mannitol infusion as standard therapy during the first 6 days of treatment. Efficacy was determined by the patients' assessments of vertigo symptoms after 1 and 4 weeks of treatment using a verbal rating scale (vertigo score) and by vestibulo-ocular and vestibulospinal tests. The primary efficacy criterion was defined as the relief of vertigo symptoms after 1 week of treatment.

RESULTS: After 1 week of treatment, the fixed combination was significantly more effective than 20 mg cinnarizine (P < 0.001) and 40 mg dimenhydrinate (P < 0.01). After 4 weeks, the fixed combination was still significantly more effective than cinnarizine in reducing vertigo symptoms (P < 0.01) and significantly more effective than dimenhydrinate in improving the patients' balance while standing (P < 0.05). The tolerability of the fixed combination was rated good or very good by 100% of the patients (cinnarizine alone, 82.4%; dimenhydrinate alone, 94.4%). No serious adverse events occurred. Four patients in the fixed combination and the cinnarizine groups, and 6 patients in the dimenhydrinate group reported nonserious adverse events.

CONCLUSIONS: The results of this study suggest a distinct benefit in using a fixed combination of cinnarizine 20 mg and dimenhydrinate 40 mg versus the respective monotherapies in this population of patients with acute vestibular vertigo.