Effects of subantimicrobial-dose doxycycline in the treatment of moderate acne.
OBJECTIVE
To determine if treatment with subantimicrobial-dose (SD) doxycycline hyclate (20-mg tablets taken twice daily) improved clinical outcome, had any detectable effect on skin flora, led to overgrowth or colonization of skin by opportunistic pathogens, or resulted in an increase in antibiotic resistance by the surface skin microflora in patients with moderate acne compared with placebo.


METHODS
Multicenter, double-blind, randomized, placebo-controlled, parallel-group trial.


METHODS
Two university-based clinics.


METHODS
Adults (N = 51) with moderate facial acne.


METHODS
Patients were randomized to receive SD doxycycline (Periostat; CollaGenex Pharmaceuticals Inc, Newtown, Pa) or placebo twice daily for 6 months. MAIN EFFICACY OUTCOMES: Primary: changes from baseline in numbers of inflammatory, noninflammatory, and total lesions. Secondary: changes from baseline of individual counts of papules, pustules, and nodules and global assessments of clinical improvement by patient and physician.


RESULTS
Forty patients completed 6 months of treatment. At 6 months, the SD doxycycline group had a significantly greater percent reduction in the number of comedones (P<.01), inflammatory and noninflammatory lesions combined (P<.01), and total inflammatory lesions (P<.05) than did the placebo group. They also had significantly greater improvement according to the clinician's global assessment (P =.03). There were no significant differences in microbial counts between groups and no evidence of change in antibiotic susceptibility or colonization by potential pathogens. The treatment was well tolerated.


CONCLUSIONS
Twice-daily SD doxycycline treatment significantly reduced the number of inflammatory and noninflammatory lesions in patients with moderate facial acne, was well tolerated, had no detectable antimicrobial effect on the skin flora, and did not result in any increase in the number or severity of resistant organisms.
Skidmore
Robert
R
Department of Medicine, Division of Dermatology, University of Florida, Gainesville, 32608, USA. skidmra@medicine.ufl.edu
Kovach
Rodney
R
Walker
Clay
C
Thomas
John
J
Bradshaw
Mark
M
Leyden
James
J
Powala
Christopher
C
Ashley
Robert
R
D000152:Acne Vulgaris / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D004318:Doxycycline / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D008297:Male; D012867:Skin / Q000382:microbiology
D000900:Anti-Bacterial Agents; D004318:Doxycycline