In January 2012, we searched for randomized controlled trials of COCs and
acne in the computerized databases of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, POPLINE, and LILACS. We also searched for clinical trials in ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) (Aug 2011). For the initial review, we wrote to researchers to seek any unpublished or published trials that we might have missed.
SELECTION CRITERIA: We extracted data on facial lesion counts, both total and specific (i.e., open or closed comedones, papules, pustules and nodules);
acne severity grades; global assessments by the clinician or the participant, and discontinuation due to adverse events. Data were entered and analyzed in RevMan. For continuous data, we calculated the mean difference (MD) and 95% confidence interval (CI). For dichotomous data, we calculated the Peto odds ratio (OR) and 95% CI.
MAIN RESULTS: The review includes 31 trials with 12,579 participants. Of 24 comparisons made, 6 compared a COC to placebo, 17 different COCs, and 1 compared a COC to an
antibiotic. Of nine placebo-controlled trials with data for analysis, all showed COCs reduced
acne lesion counts, severity grades and self-assessed
acne compared to placebo. A
levonorgestrel-COC group had fewer total lesion counts (MD -9.98; 95% CI -16.51 to -3.45), inflammatory and non-inflammatory lesion counts, and were more likely to have a clinician assessment of clear or almost clear lesions and participant self-assessment of improved
acne lesions. A
norethindrone acetate COC had better results for clinician global assessment of no
acne to mild
acne (OR 1.86; 95% CI 1.32 to 2.62). In two combined trials, a
norgestimate COC showed reduced total lesion counts (MD-9.32; 95% CI -14.19 to -4.45), reduced inflammatory lesion and comedones counts, and more with clinician assessment of improved
acne. For two combined trials of a
drospirenone COC, the investigators' assessment of clear or almost clear skin favored the
drospirenone group (OR 3.02; 95% CI 1.99 to 4.59). In one trial, the
drospirenone-COC group showed greater (more positive) percent changes for total lesion count (MD 29.08; 95% CI 3.13 to 55.03), inflammatory and non-inflammatory lesion counts, and papule and closed comedone counts. A
dienogest-COC group had greater percentage decreases in total lesion count (MD -15.30; 95% CI -19.98 to -10.62) and inflammatory lesion count, and more women assessed with overall improvement of facial
acne. A CMA-COC group had more 'responders,' those with 50% or greater decrease in facial papules and pustules (OR 2.31; 95% CI 1.50 to 3.55)Differences in the comparative effectiveness of COCs containing varying
progestin types and dosages were less clear, and data were limited for any particular comparison. COCs that contained
chlormadinone acetate or
cyproterone acetate improved
acne better than
levonorgestrel. A COC with
cyproterone acetate showed better
acne outcomes than one with
desogestrel, but the studies produced conflicting results. Likewise,
levonorgestrel showed a slight improvement over
desogestrel in
acne outcomes, but results were not consistent. A
drospirenone COC appeared to be more effective than
norgestimate or
nomegestrol acetate plus 17β-estradiol but less effective than
cyproterone acetate.
AUTHORS' CONCLUSIONS: This update yielded six new trials but no change in conclusions. The six COCs evaluated in placebo-controlled trials are effective in reducing inflammatory and non-inflammatory facial
acne lesions. Few important and consistent differences were found between COC types in their effectiveness for treating
acne. How COCs compare to alternative
acne treatments is unknown since only one trial addressed this issue. The use of standardized methods for assessing
acne severity would help in synthesizing results across trials as well as aid in interpretation.