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How Quickly Should Bactrim DS Stop Cystic Acne?

Several tetracyclines have failed ( doxy, mino, solodyn) as have topicals (evoclin, triaz, duac, retin-a, aczone. I started Bactrim DS 3 weeks ago (2x daily) but I am still experiencing new cysts on my back ( none on my face/chest).

How soon should this stop them? Should I still be getting new cysts 3 weeks in ? They are causing raised scars on my chest & back. I am classified as 'moderate cystic acne with very mild rosacea'. My derm has me taking it until July and re-evaluating at that time.

Doctor Answers (2)

Bactrim for Acne


Bactrim is not an antibiotic that I typically prescribe for Acne as it is a rather "big gun" antibiotic for serious infections.  As it can be very effective for acne, Bactrim has significant side effects such as causing a life threatening rash.  However, in severe acne cases I may prescribe it for 1-2 weeks for quick control of severe cystic acne prior to initiating another treatment regimen.

Houston Dermatologist

Bactrim and cystic acne


I am generally not in favor of long-term antibiotics for acne so even if Bactrim were helpful, long-term use can cause bacterial resistance and a decrease in effectiveness over time.  You may want to discuss the option of Accutane with your dermatologist.  While Accutane has its share of potential side effects, it is a consideration when other therapies including oral antibiotics have failed.

Bryan K. Chen, MD
San Diego Dermatologist
5.0 out of 5 stars 4 reviews

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