SAN FRANCISCO — Prescribing has been gradually moving away from antimicrobial agents and toward increased use of retinoids in the treatment of acne vulgaris.
The shift toward nonantibiotics, reported in an analysis of national prescription habits between 1990 and 2002, may in part be explained by a growing awareness of antibiotic-resistant Propionibacterium acnes, wrote Dr. Suganthi Thevarajah and her associates in a poster presentation at the annual meeting of the American Academy of Dermatology.
The first report of antibiotic resistance to cutaneous P. acnes appeared in the late 1970s. The study showed that one in five U.S. patients treated with either topical erythromycin or clindamycin had resistant strains within their pilosebaceous follicles, noted Dr. Thevarajah of Hospital Kuala Lumpur, Malaysia. Dr. Thevarajah led the study while at the Center for Dermatology Research, Wake Forest University, Winston-Salem, N.C. The center is supported by a grant from Galderma Laboratories, which makes acne treatments.
She and her associates retrospectively analyzed data from all 4,922 acne visits from 1990 to 2002 in the National Ambulatory Medical Care Survey. The survey consists of outpatient information obtained from U.S. non-federally employed physicians.
During the 13-year period, there were significant declines in the likelihood of prescribing agents that relied on antimicrobial mechanisms for controlling acne. Included among these were benzoyl peroxide, topical clindamycin, oral erythromycin, and tetracycline-group antibiotics. In the same time period, there were significant increases in the likelihood of prescribing agents that were not dependent on antimicrobial mechanisms, such as topical retinoids and oral isotretinoin.
“Cross-resistance between erythromycin and clindamycin is increasing. This knowledge may have resulted in a decline in prescriptions for topical antibiotics as seen in our study,” Dr. Thevarajah wrote.
While use of tetracycline-group antibiotics decreased overall, their use actually increased among dermatologists. This may be because dermatologists are increasingly prescribing them for their anti-inflammatory effects rather than their antimicrobial properties, she added. Dermatologists were more likely than nondermatologists to prescribe benzoyl peroxide, clindamycin, isotretinoin, topical retinoids, and tetracycline-group antibiotics.
Controls for demographics did not change the utilization findings. Older patients were less likely to receive clindamycin, topical retinoids, benzoyl peroxide, tetracycline-group antibiotics, and isotretinoin. Men were less likely to receive clindamycin and topical retinoids and more likely to receive tetracycline-group antibiotics and oral isotretinoin. Whites were more likely than nonwhites to get isotretinoin but less likely to be given benzoyl peroxide.