Safety and Efficacy Comparison of Minocycline Microgranules vs Lymecycline in the Treatment of Mild to Moderate Acne: Randomized, Evaluator-Blinded, Parallel, and Prospective Clinical Trial for 8 Weeks

Background: Minocycline and lymecycline are used in the treatment of acne, but there is not enough evidence to support superior efficacy of one of them. Methods: 170 participants from 14 to 34 years old with mild to moderate facial acne vulgaris were recruited. 84 had 100 mg of minocycline in a single daily dose for 8 weeks and 86 had 300 mg of lymecycline in a single daily dose for 8 weeks. Participants were evaluated at baseline, week 4 and week 8. Results: 65 minocycline and 60 lymecycline patients were evaluable. The last observation carried forward for the count of non-inflammatory lesions changed from 375 +/- 178 to 37.7 +/- 178 in the minocycline group and from 36.9 +/- 15.5 to 33.4 +/- 19.3 in the lymecycline group (no significant changes); corresponding changes in inflammatory lesions were from 19.4 +/- 12.4 to 12.2 +/- 10.0 in the minocycline group and from 20.1 +/- 11.3 to 12.6 +/- 8.4 in lymecycline group (P<0.05 comparing baseline vs. final in both groups). Porphyrin counts varied from 899.5 +/- 613.9 to 233.5 +/- 219.5 in the minocycline group and from 956.9 +/- 661.8 to 411.8 +/- 411.5 in the lymecycline group (P<0.05 between the groups at study end). 36 (42.9%) patients receiving minocycline suffered 55 adverse events (22 of them gastrointestinal), while 28 (33.3%) lymecycline patients had 37 adverse events (15 of them gastrointestinal). One patient in the lymecycline group withdrew the study due to gastritis, and one more patient in the same group experienced eosinophilia. Conclusions: There were no differences between the groups in non-inflammatory and inflammatory lesion counts, and in the safety profile. Treatment with minocycline induced statistically significant decrease in facial porphyrin counts compared to the group treated with lymecycline (ClinicalTrials.gov number, NCT00988026).