Background: Acute otitis media (AOM) is a spontaneously remitting disease for which pain is the most distressing symptom. Antibiotics are now known to have less benefit than previously assumed.
Objectives: To assess the effectiveness of topical analgesia for AOM.
Search strategy: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2006), MEDLINE (1966 to May Week 3 2006), EMBASE (1990 to December 2005) and LILACS (1982 to September 2005) without language restriction, and the reference lists of articles. We also contacted manufacturers and authors.
Selection criteria: Double-blind randomised or quasi-randomised controlled trials comparing an otic preparation with an analgesic effect (excluding antibiotics) versus placebo or an otic preparation with an analgesic effect (excluding antibiotics) versus any other otic preparation with an analgesic effect, in adults or children presenting at primary care settings with AOM without perforation.
Data collection and analysis: Potential studies were screened independently and trial quality was assessed by three authors, and differences were resolved by discussion. Data was then independently extracted from the trials selected by two authors. We contacted the authors of three trials to acquire additional information not available in published articles.
Main results: Our searches yielded 356 records; four trials met our criteria. One trial with 54 participants compared treatment with anaesthetic ear drops versus an olive oil placebo immediately at diagnosis. All patients were also given paracetamol. There was a statistically significant pain reduction of 25% in those receiving anaesthetic drops 30 minutes after instillation. Three trials (with one common co-author) compared anaesthetic ear drops with naturopathic herbal ear drops in 274 patients. One of these trials also used antibiotics in both groups. There were statistically significant differences at instillation of drops, or 15 or 30 minutes after the instillation (or both) on one to three days after diagnosis, always favouring the naturopathic group in each trial.
Authors' conclusions: The evidence from these four randomised controlled trials, only one of which addresses the most relevant question of primary effectiveness, is insufficient to know whether ear drops are effective or not.