Why Do Doctors Use Antibiotics To Treat Acne?

You’ve just gone to the doctor for acne treatment and walked out with a new prescription for a three month supply of antibiotics. You’re not alone. Estimates peg dermatologists at prescribing 8 to 9 million oral antibiotics and 3 to 4 million topical antibiotics every year to treat acne.^[1] Acne is not considered an infection.^[2] So why are antibiotics used so commonly? 

Antibiotics Have Non-Antibiotic Effects

Although antibiotics were originally discovered and used to treat infection, research has shown that they have several non-antibiotic effects:^[2]

• Antibiotics have anti-inflammatory actions^[3]
• Antibiotics inhibit the production of reactive oxygen species by preventing neutrophils (an inflammatory cell) from producing them.^[4] Tetracyclines (such as doxycycline and minocycline) were more effective at inhibiting the reactive oxygen species than the other tested antibiotics.^[4]
• Antibiotics inhibit the breakdown of tissue. The inflammation caused by acne can lead to damage to the surrounding skin, which can lead to uneven texture and scarring. In particular, the tetracycline family of antibiotics, such as doxycycline and minocycline inhibit the actions of proteins that can normally break down tissue.^[5,6] This may reduce the damage to the skin around the acne lesion, although more clinical studies are needed to evaluate this. 

If you think about these properties of antibiotic medications, it makes sense to use them for their anti-inflammatory properties. This also explains the stark difference in the duration of treatment. In general, antibiotics for infections are written for 10-14 days. However, when using antibiotics for inflammation, longer durations (several months) are required in order to achieve the desired outcome.^[7]

Antibiotics Work for Acne but Have Side Effects

Antibiotics are considered first-line therapy in the treatment of acne, which is why they are used so widely and frequently in the treatment of acne. Some of the typical antibiotics used are listed below including those that are FDA approved for acne and those that are used as off-label acne treatments: 

• Tetracycline family of antibiotics: Doxycycline and Minocycline
• Macrolide family of antibiotics: Erythromycin and Azithromycin 
• Lincosamide family of antibiotics: Clindamycin
• Penicillin family of antibiotics: Ampicillin and Amoxicillin
• Trimethoprim/Sulfamethoxasole

These antibiotics must be discussed with a qualified health provider to see if a prescription is appropriate and for a full discussion of the side effects of these antibiotics. 

Both topical and oral antibiotics are prescribed regularly in both the United States and abroad.^[8-10] Unfortunately, one of the consequences is the development of antibiotic-resistant bacteria. A worldwide survey of antibiotic resistance showed that some countries have antibiotic resistance rates in P. acnes (the bacterium involved in acne) as high as 90 to 100% for some of the antibiotics.^[9] 

What is more concerning is the possibility that this use of antibiotics may lead to resistance in other bacteria that can create more dangerous illnesses. For example, antibiotics like trimethoprim/sulfamethoxazole, doxycycline, and minocycline are effective in the treatment of methicillin-resistant S. aureus (MRSA),^[11] a drug-resistant bacterium that can lead to serious skin and internal infections. Thus far, there is no evidence that MRSA resistance rates are increasing due to antibiotic use in acne.^[12] However, others have stated that drug-resistant bacteria may develop in the future and that carefully conducted studies are needed to more closely evaluate this possibility.^[13] Yet other physicians have reported the development of doxycycline resistant MRSA in a few patients after exposure to long courses of doxycycline, similar to how they are used in acne.^[14] 

The long-term consequences in using antibiotics have led to the emergence of drug-resistant P. acnes bacteria. The potential to create drug-resistance among MRSA bacteria is concerning and will require further clinical studies. In the meantime, careful use of antibiotics will be important. Physicians and patients should be aware of these risks and to plan treatments so that antibiotic exposures are reduced. 

Reducing Exposure to Antibiotics 

People with moderate to severe acne are exposed to 11 months of antibiotics before they start other therapies.^[15] The recommendations for how antibiotics should be used are shifting toward more careful use of antibiotics, focusing on reducing antibiotic exposure, and the use of non-antibiotic alternatives. These recommendations may include the following concepts: 

• When people are started on antibiotics, they may benefit from the addition of other non-antibiotic topical medications along with the antibiotics.^[16,17] 
• It is suggested that the duration of exposure to antibiotics be limited^[10,17] and should be discussed carefully with the health care practitioner. 
• Non-antibiotic options to oral antibiotics include the use of medications that can alter the hormones in the body. Two examples include oral contraceptive pills and spironolactone. Both of these should be discussed with a qualified healthcare practitioner to discuss the benefits, risks, and side effects of using such medications. In general, medications that alter hormones are not appropriate for use in males. 
• The use of isotretinoin could be considered in cases of moderate to severe acne and needs to be discussed with a qualified health practitioner if it is a possibility. 

Ultimately, more research is needed to develop alternative non-antibiotic therapies for acne. This includes the use of alternative medical approaches, botanicals, and light-based therapies. However, until more therapies are carefully studied, antibiotics remain an effective therapy for the treatment of acne. They should be mindfully used to minimize the development of drug-resistant bacteria.