Key takeaways
Sulfamethoxazole/trimethoprim (Bactrim, Septra) and clindamycin (Cleocin) are both antibiotics used to treat bacterial infections, including lower respiratory tract infections like pneumonia. However, they belong to different medication classes. Sulfamethoxazole/trimethoprim is a sulfonamide antibiotic, while clindamycin is a lincosamide antibiotic. Sulfamethoxazole/trimethoprim is available in oral, liquid, and injection forms and is typically taken twice a day, whereas clindamycin is available as a capsule, liquid, and injection, and is usually taken three or four times a day. Both medications are available as lower-cost generics. Common side effects of sulfamethoxazole/trimethoprim include nausea, diarrhea, and rash, while clindamycin can cause stomach upset, itching, and rash. Sulfamethoxazole/trimethoprim interacts with warfarin and dofetilide (Tikosyn), whereas clindamycin interacts with medications like warfarin and amiodarone. Additionally, sulfamethoxazole/trimethoprim is not recommended during pregnancy, while clindamycin may be used early in pregnancy if necessary.
