Metronidazole in the treatment of rosacea: do formulation, dosing, and concentration matter?

Topical metronidazole is commonly used in the management of rosacea. No consensus on the optimal formulation, concentration, or dosing regimen exists.

To assess the relative efficacy of metronidazole cream, gel, and lotion at concentrations of 0.75% and 1%, in dosing regimens of once and twice daily.

A meta-analysis of published metronidazole efficacy rates was performed.

In non-weighted analysis, the mean efficacy was 28.2% (95% confidence interval [CI], 22.0%-34.4%) for the cream, 38.4% (95% CI, 18.4%-58.4%) for the gel, and 35% for the lotion. Confidence intervals for QD versus BID dosing and 0.75% versus 1% concentrations also overlapped. In weighted analysis, the mean reduction was 31.3% for the cream, 22.1% for the gel, and 35% for the lotion.

Metronidazole cream, gel, and lotion vehicles have similar efficacies. There were no substantial differences between concentrations of 0.75% and 1%, or between once daily and twice daily regimens.