Co-trimoxazole is a combination medication containing the antibiotic trimethoprim and the sulfa drug sulfamethoxazole. This prescription-only drug eliminates bacteria that cause various infections. Doctors commonly prescribe antibiotics to treat moderate to severe acne, and although co-trimoxazole is generally not the first choice of antibiotic treatment for acne, it is suitable in some cases.
Uses
Co-trimoxazole is effective for treating bacterial infections of the ears, lungs, urinary tract and intestines, including traveler's diarrhea, according to MedlinePlus. Trimethoprim by itself is usually prescribed for urinary tract infections, and sulfamethoxazole is generally prescribed as part of a combination medication, to add potency to trimethoprim or another drug. The U.S. Food and Drug Administration has not approved these drugs for treating acne, but doctors are allowed to prescribe legal medications for so-called off-label use.
Antibiotics for Acne
Oral antibiotics are a main course of therapy for people with moderate to severe acne and for persistent cases, according to the American Academy of Dermatology. They tend to be more effective than topical antibiotics and antimicrobial preparations at reducing facial bacteria. Doctors usually prescribe antibiotic treatment for six months or less, beginning with a higher dose and reducing it as the condition clears. Like other bacteria, the acne-causing bacteria Propionibacterium acnes can become resistant to the antibiotic being used to treat it, and then the doctor may prescribe a different antibiotic.
Types
Tetracycline and derivatives of tetracycline such as doxycycline and minocycline, are the most commonly prescribed antibiotics for acne, along with erythromycin, according to the AAD. Doxycycline is particularly effective at treating inflammatory acne. Doctors also prescribe azithromycin, trimethoprim, and the combination of trimethoprim and sulfamethoxazole for acne treatment.
Considerations
Some patients do not experience much improvement with commonly prescribed antibiotics for acne, explains an article published in "Dermatology" in 1993. The authors investigated the effects of trimethoprim as an option for individuals whose acne did not respond to at least two courses of antibiotics, and they found significant improvement connected with trimethoprim at 300 mg twice per day for four months, along with a twice-daily application of 1 percent clindamycin lotion. An article published in the Dec. 14, 2002 issue of "BMJ" advises against using co-trimoxazole for acne because sulphamethoxazole can cause additional side effects, and research has not indicated that co-trimoxazole is more effective than trimethoprim alone.
Side Effects
One reason doctors avoid prescribing trimethoprim or co-trimoxazole as first-line treatment is the risk of allergy. Allergy to tetracycline drugs and erythromycin is very uncommon, according to the New Zealand Dermatological Society at its DermNet NZ website, but over 2 percent of people have allergic reactions to trimethoprim and co-trimoxazole. The most common side effects associated with co-trimoxazole are gastrointestinal, according to MedlinePlus, including loss of appetite, upset stomach, nausea and vomiting.
