No evidence of clinical efficacy of oxomemazine in cough, according to a systematic review.

Purpose: Cough is a prevalent symptom driving patients to seek medical attention in general practice. Despite its widespread use, the clinical efficacy of oxomemazine, the second most reimbursed molecule in France for symptomatic cough treatment, remains uncertain. This study aims to systematically evaluate the clinical efficacy of oxomemazine in cough.

Methods: A systematic literature review with meta-analysis of randomized controlled trials (RCTs) was conducted according to the Rebuild the Evidence Base (REB) protocol. Clinical trials comparing the efficacy of oxomemazine versus placebo or active comparator in cough were searched for. Trials with insufficient data were excluded. Searches were conducted across major databases (Medline, Cochrane Central Register of Controlled Trials, and Embase) and trial registries (World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov). RCTs comparing oxomemazine versus placebo or active comparators in cough were sought. Risk of bias was assessed using the Cochrane Collaboration's RoB2 tool. The protocol was preregistered on PROSPERO under the number CRD42022345496 (15). This study received no funding.

Results: No RCTs were at low risk of bias. Therefore, no meta-analysis was conducted, in accordance to the pre-specified protocol.

Conclusions: This systematic review highlights the lack of evidence regarding the efficacy of oxomemazine in cough treatment and underscores the need for further well-designed clinical trials to inform its clinical utility in primary care settings.