Trimethoprim/sulfamethoxazole is another oral antibiotic option for acne. It is administered 160 mg/800 mg twice daily. It works by inhibiting dihydrofolate reductase thus impeding purine and pyrimidine synthesis. It has a broad spectrum of antimicrobial activity, and therefore should be reserved as a second line agent or for patients with gramnegative folliculitis. Due to its sulfa moiety, trimethoprim/sulfamethoxazole also has the potential to cause a drug hypersensitivity syndrome with multi-organ involvement. Anemia, thrombocytopenia, and agranulocytosis are also potential side effects of trimethoprim/sulfamethoxazole.