Hematologic safety of dapsone gel, 5%, for topical treatment of acne vulgaris.

OBJECTIVE To evaluate the risk of hemolysis in subjects with glucose-6-phosphate dehydrogenase (G6PD) deficiency who were treated for acne vulgaris with either dapsone gel, 5% (dapsone gel), or vehicle gel. DESIGN Double-blind, randomized, vehicle-controlled, crossover study. SETTING Referral centers and private practice. PARTICIPANTS Sixty-four subjects 12 years or older with G6PD deficiency and acne vulgaris. Intervention Subjects were equally randomized to 1 of 2 sequences of 12-week treatment periods (vehicle followed by dapsone gel or dapsone gel followed by vehicle). The washout period was 2 weeks. Treatments were applied twice daily to the face and to other acne-affected areas of the neck, upper chest, upper back, and shoulders as required. MAIN OUTCOME MEASURES Results of clinical chemical analysis and hematology values; plasma dapsone and N-acetyl dapsone concentrations; spontaneous reports of adverse events. RESULTS A 0.32-g/dL decrease in hemoglobin concentration occurred from baseline to 2 weeks during dapsone gel treatment. This was not accompanied by changes in other laboratory parameters, including reticulocytes, haptoglobin, bilirubin, and lactate dehydrogenase levels, and was not apparent at 12 weeks as treatment continued. The number of subjects with a 1-g/dL drop in hemoglobin concentration was similar between treatment groups at both week 2 and week 12. The largest drops in hemoglobin concentration were 1.7 g/dL in the vehicle gel treatment group and 1.5 g/dL in the dapsone gel treatment group. No clinical signs or symptoms of hemolytic anemia were noted. CONCLUSIONS After treatment with dapsone gel, 5%, no clinical or laboratory evidence of drug-induced hemolytic anemia was noted in G6PD-deficient subjects with acne vulgaris. Trial Registration clinicaltrials.gov Identifier: NCT00243542.