[Vasodilators for sudden sensorineural hearing loss: a systematic review of randomized controlled trials].

OBJECTIVE: To assess the effects and safety of vasodilators on sudden sensorineural hearing loss(SSHL).

SEARCH STRATEGY: Electronic databases: MEDLINE from 1966, EMBASE from 1974, the Cochrane Controlled Trails Register, Chinese Bio-medicine Database from 1989. Hand search: Five kinds of Chinese otolaryngology journals were selected. Literature references were checked intensively.

SELECTION CRITERIA: Randomized controlled trials comparing vasodilators with placebo or other drugs in patients with SSHL.

DATA COLLECTION AND ANALYSIS: Three reviewers independently accessed the quality of trials and extracted the data.

RESULTS: Thirteen trials with 1,155 patients were eligible and covered in the systematic review. Ten of the trials were conducted in developed countries, and three in China. None of the four trials showed the effects of vasodilators on SSHL were better than that of placebo. None of the seven trials comparing different drugs showed the effects of one kind of vasodilators were better than that of the other vasodilators. Two trials showed that some other drugs, such as batroxobin and hypaque were probably better than the vasodilators (dextran, papaverine, 654-2, danshen). Eight trials showed side effects of vasodilators, such as pruritus, allergy, etc.

CONCLUSIONS: Based on the systematic review of current eligible randomized controlled clinical trials, there is no evidence to prove that vasodilator therapy is more effective than placebo or other therapies for SSHL, or the effects of one kind of vasodilators to be better than that of the other vasodilators. So far we can't draw a reliable conclusion about the effects of vasodilators for SSHL. In addition, we must pay attention to their potential adverse reactions.