Treatment of idiopathic sudden sensorineural hearing loss with antiviral therapy: a prospective, randomized, double-blind clinical trial.

A subclinical viral labyrinthitis has been postulated in the literature to elicit idiopathic sudden sensorineural hearing loss (ISSHL). An etiologic role for the herpes family is assumed. Corticosteroids possess a limited beneficial effect on hearing recovery in ISSHL. In this study, we evaluated the therapeutic value of the antiherpetic drug acyclovir (Zovirax) on hearing recovery in 91 patients with ISSHL who received prednisolone in a prospective, randomized, double-blind, placebo-controlled, multicenter trial. The audiometric parameters included pure tone and speech audiometry. Subjective parameters studied included hearing recovery, a pressure sensation in the affected ear, vertigo, and tinnitus. A 1-year follow-up was obtained. Hearing recovery for the whole group averaged about 35 dB and was independent of the severity of the initial hearing loss or vestibular involvement. Speech audiometry improved from 49% to 75%. After 12 months, pressure sensation and vertigo decreased to 15.6% (acyclovir) and 10.3% (placebo) and 12.5% (acyclovir) and 10.7% (placebo), respectively. Tinnitus decreased slightly, to 46.9% (acyclovir) and 55.2% (placebo), in the same period (p > .05 for all parameters). We conclude that no beneficial effect from combining acyclovir with prednisolone can be established in patients with ISSHL.