Bell's palsy: a review of treatment using antiviral agents.

OBJECTIVE: To review the evidence evaluating the efficacy and safety of antiviral agents to reduce morbidity associated with Bell's palsy. DATA SOURCES: MEDLINE, EMBASE, and PubMed were searched (all up to April 2006) for English-language, prospective, randomized, controlled clinical trials that evaluated the use of antiviral agents in Bell's palsy. Search terms included Bell's palsy, acyclovir, valacyclovir, famciclovir, and randomized controlled trials. STUDY SELECTION AND DATA EXTRACTION: Prospective, randomized, controlled trials that evaluated efficacy and safety endpoints of antiviral agents in the treatment of Bell's palsy were included. Primary efficacy outcomes included facial paralysis recovery profile, facial paralysis recovery index, and the House-Brackmann facial nerve grading scale. Safety outcomes were also identified by each trial. DATA SYNTHESIS: Two prospective, randomized clinical trials were included in this review, both involving the use of acyclovir for treatment of Bell's palsy. Acyclovir monotherapy was shown to be inferior to prednisone monotherapy; however, the combination of acyclovir and prednisone was found to be superior to prednisone alone. There are limited data describing the safety of acyclovir in Bell's palsy. CONCLUSIONS: The use of acyclovir in the treatment of Bell's palsy remains controversial. Additional, adequately powered, randomized, placebo-controlled trials are needed to definitively support its use. For the time being, the evidence reviewed in this article would favor the combination of acyclovir and prednisone if commenced within the first 72 hours of symptom onset.