Effectiveness and safety of subantimicrobial dose doxycycline compared to standard dose doxycycline in the treatment of patients with acne: systematic review and meta‐analysis

Aim To assess the effectiveness and safety of doxycycline at a subantimicrobial dose compared to doxycycline at an antimicrobial dose in people with acne. Data Sources We conducted a literature search of MEDLINE, Embase, Latin American and Caribbean Literature on Health Sciences (LILACS), Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar, OpenGrey database, ClinicalTrial.gov and thesis database sources from inception to March 2020. The bias analysis was performed according to the Cochrane Collaboration, using the RevMan 5.3 program, classifying the articles as high, indeterminate, and low risk of bias. Study selection From a total of 904 records identified, we selected two studies comparing the effectiveness and safety of subantimicrobial (40 mg daily) and antimicrobial (100 mg daily) doses of doxycycline in managing facial acne. Two researchers independently evaluated the articles and selected them for the final analysis according to the eligibility criteria. We performed a meta‐analysis using a random‐effects model. Results We included two randomised clinical trials with a total of 762 patients, each using a 40 mg dose of doxycycline. We did not find statistically significant differences in the decrease of inflammatory lesions in people with acne between the two comparison groups at 4 weeks (mean difference [MD] = 0.06, 95% confidence interval [CI] −0.38 to 0.49, I 2 = 75.3%), at 8 weeks (MD = 0.16, 95% CI −3.47 to 3.78, I 2 = 99.49%), and at 12 weeks (MD = 0.86, 95% CI −2.57 to 4.29, I 2 = 99.35%). Conclusion Based on initial data from two studies, subantimicrobial dose doxycycline appears to have a similar efficacy to the standard dose in treating inflammatory acne lesions and may be associated with fewer adverse events.