Objectives: To evaluate the efficacy and safety of metformin as an adjunct to oral doxycycline and tretinoin 0.025% cream in the treatment of moderate to severe acne vulgaris. Methods: This is a double blind randomized controlled trial with 17 patients per group, and a study period of 12 weeks. Both groups (Dt group and DtM group) received doxycycline for the first 6 weeks and tretinoin for 12 weeks, while only the DtM group received metformin 1500mg/day for the entire treatment period. Follow up visits were done every 2 weeks from baseline. Non-inflammatory, inflammatory and total acne lesion count, and the modified global severity, subjective patient assessment, and Dermatology Life Quality Index scores, scores of cutaneous adverse events, and incidence and frequency of systemic adverse events were the outcome measures. Results: The DM group showed significant statistical benefit for the treatment of noninflamma-tory lesions (comedones) in the 4th, 6th, 8th and 12th week. Outcome measures of global severity, subjective patient assessment, and DLQI scores, mean reduction rate of inflammatory and total lesion counts, and mean pain, erythema, dryness and scaling counts between groups were comparable. The incidence and frequency of reported systemic adverse events such as diarrhea, nausea and headache, were higher in the DtM group. Conclusion The addition of metformin to standard treatment is beneficial in reducing non-inflammatory lesion counts. It offers comparable benefit for inflammatory and total lesion counts. Cutaneous and systemic adverse events in both groups were mild and self-limited, and did not warrant discontinuation of treatment.
Metformin ; Tretinoin ; Doxycycline ; Therapeutics ; Acne Vulgaris