LAKE TAHOE, CALIF. – Dermatologists prescribe more antibiotics than any other physician group, a statistic that George G. Zhanel, PhD, would like to see go by the wayside.
Dr. George G. Zhanel
After all, the World Health Organization projects that the number of annual deaths in North America attributable to antibiotic resistance will reach 317,000 by the year 2050.
Dr. Zhanel, a microbiologist at the College of Medicine, University of Manitoba, Winnipeg, Canada, said at the annual meeting of the Society for Pediatric Dermatology. “Many of us are very concerned about this. Countries have put together an optimal action plan. What are we going to do about this? The plans are quite similar from country to country. They talk about surveillance, finding where these pathogens are. They talk about infection control such as washing your hands in the clinic so you’re not moving antibiotic-resistant organisms around. They talk about diagnostic and treatment guidelines, new antibiotic therapies, probiotics, and vaccination strategies. My own group is doing research on all of these areas, but today I’m going to focus on antibiotic stewardship: Using antibiotics wisely, trying to optimize efficacy while trying to minimize the development of resistant organisms.”
Dr. Zhanel, who is also director of the Canadian Antimicrobial Resistance Alliance (CARA) at the College of Medicine, University of Manitoba, described dermatologists as “big players” when it comes to antibiotic use. According to a 2016 report from the Scientific Panel on Antibiotic Use in Dermatology, dermatologists order 8.2 million oral antibiotic prescriptions each year, which is more common than any other physician group based on the prescribing rate per clinician (J Clin Aesthet Dermatol. 2016;9[4]:18-24). In addition, the prescribed duration of antibiotic therapy is often markedly longer with therapies treated by dermatologists, especially acne and rosacea. One study of general practitioners in the United Kingdom found that the mean duration of oral antibiotic use for treating acne was 175 days (J Am Acad Dermatol 2016;75:1142-50). “For some patients it went on much longer,” said Dr. Zhanel, who was not affiliated with the study.
“You are important players when it comes to antibiotics. How you use them and if you use them wisely impacts not only your patients, but the world.”
The correlation between antibiotic use and resistance is widely established, he continued. “We have known for 30 to 40 years that if you treat patients with tetracyclines, the Staphylococcus epidermidis that we all have on our skin develop tetracycline resistance,” he said. “The tetracycline resistance genes from S. epidermidis can then transfer to putative pathogens such as Staphylococcus aureus, and potentially [methicillin-resistant S. aureus]. That’s why we need to try to minimize oral tetracycline exposure on the normal microbiome.” In addition, tetracycline use can help create multidrug resistant organisms.
Next, Dr. Zhanel discussed potential solutions to antimicrobial usage/resistance in dermatology. According to recent guidelines on the care for the management of acne vulgaris, systemic antibiotic use should be limited to the shortest possible duration, typically 90 days (J Am Acad Dermatol. 2016;74[5]:945-73). A common treatment for moderate to-severe acne is to combine a topical retinoid with an oral or topical antimicrobial (J Am Acad Dermatol. 2009;60(5 suppl):S1-S50). If the addition of an oral antibiotic is required, limit its use to 3 or 4 months and co-prescribe with a product that contains benzoyl peroxide (BPO), or use as a washout. “Ideally, that’s your exit strategy,” he said. “Once you finish the oral antibiotic, in about 3 months if possible, continue with the topical retinoids plus BPO to maintain that particular remission.”
Why add benzoyl peroxide to topical retinoids for maintenance therapy? “Benzoyl peroxide and topical retinoids affect multiple targets in your acne strategy, and when you use them together they are powerful,” Dr. Zhanel said. He advises dermatologists not to prescribe oral or topical clindamycin unless they have to, because that drug is one of the main drivers of Clostridium difficile infection.
Dr. Zhanel’s stewardship tips for topical antibiotics involve not using topical tetracyclines/clindamycin/macrolides, in favor of using a topical antimicrobial such as BPO. “We think that benzoyl peroxide is less likely to drive resistance than are the traditional topical antibiotics like tetracyclines and clindamycin,” he said. “Use topical retinoids and benzoyl peroxide, if possible.”
Subtherapeutic oral doses of tetracyclines such as doxycycline 40 mg modified release “look very powerful for treating rosacea and do not affect the normal microbiome or select for resistance,” he said. In the meantime, Dr. Zhanel and other researchers are working to develop narrow spectrum tetracyclines with less impact on the GI flora, such as sarecycline. “So there is the potential for more eco-friendly tetracyclines,” he said.
Going forward, many questions remain about optimal antibiotic stewardship in dermatology, Dr. Zhanel said. For example, if you combine a topical antibiotic with benzoyl peroxide, are you less likely to get resistance to that topical antibiotic? “I think the answer is yes, but the literature isn’t very strong on that,” he said. “Also, is benzoyl peroxide plus a topical retinoid better than benzoyl peroxide plus a topical antibiotic in terms of resistance? I think the answer is yes, but again there is very little data on this.”
Dr. Zhanel disclosed having numerous financial ties to the pharmaceutical industry.