We conducted a randomized controlled trial in patients with
acne vulgaris with moderate to severe inflammatory lesions. The patients were assigned to the following three treatment groups: group A received monotherapy with 0.1% topical
adapalene gel for 4 weeks; group B received combination
therapy with 0.1% topical
adapalene gel and 600 mg oral
faropenem for 2 weeks followed by 0.1% topical
adapalene gel alone for 2 weeks; and group C received combination
therapy with 0.1% topical
adapalene gel and 600 mg oral
faropenem for 4 weeks. The result of the analysis indicated that the percentage reduction in inflammatory lesion counts after 2 weeks of treatment was significantly higher in groups B and C than in group A (P < 0.05). After 4 weeks of treatment, group C showed significantly higher percentage reduction in inflammatory lesion counts than in groups A and B (P < 0.05), whereas no significant difference was noted between the latter two groups. Adverse reactions included dryness and irritation at the
adapalene application sites that were observed in 10.1% of cases (16/158 patients) and
diarrhea and loose stool because of oral
faropenem that were observed in 7.5% of cases (8/106 patients). Taken together, our results suggest that combination
therapy with oral
antibiotics and
adapalene results in earlier improvement in patients with moderate to severe inflammatory
acne compared to the application of
adapalene alone, and that 4 weeks of the combination
therapy is preferable to 2 weeks of treatment.