Can Bactrim and Clindamycin Be Taken Together?
Yes, Bactrim (trimethoprim-sulfamethoxazole) and clindamycin can be safely taken together, and this combination is specifically recommended by the European Society of Cardiology as an alternative therapy for Staphylococcus aureus infections, including both methicillin-susceptible and methicillin-resistant strains. 1
Evidence Supporting Combination Use
The combination of these two antibiotics has established clinical support:
The European Society of Cardiology explicitly recommends this combination for treating Staphylococcus aureus infections, with specific dosing of trimethoprim-sulfamethoxazole at 4800 mg/day (sulfamethoxazole) and 960 mg/day (trimethoprim) in 4-6 divided doses, plus clindamycin at 1800 mg/day IV in 3 doses. 1
Multiple CDC and IDSA guidelines reference both agents together in treatment algorithms for opportunistic infections, particularly in HIV-infected patients, without any contraindication to concurrent use. 2
Clinical research demonstrates safety of the combination, with a 1977 study showing no instances of antagonism when these drug classes were used together, and adverse reactions were mild and reversible. 3
Clinical Context for Combined Therapy
The combination is most appropriate in specific scenarios:
For severe Staphylococcus aureus infections including endocarditis, where the combination provides alternative coverage when first-line agents cannot be used. 1
In bioterrorism-related anthrax, CDC guidelines note that regimens including ciprofloxacin, rifampin, and clindamycin have been used, though trimethoprim-sulfamethoxazole is specifically not recommended for anthrax therapy itself. 2
For toxoplasmosis treatment, pyrimethamine plus either sulfadiazine or clindamycin is recommended, showing these drug classes work together without interaction concerns. 2
Important Safety Considerations
When prescribing both medications together, monitor for:
Increased gastrointestinal side effects, as both medications can cause diarrhea, and the risk may be additive when used together. 1
Clostridioides difficile-associated diarrhea risk, particularly with clindamycin, which carries this well-established complication. 1
Overlapping skin reactions, as both medications can cause cutaneous adverse effects including rash. 1
Trimethoprim-sulfamethoxazole is contraindicated in pregnant women near term, nursing mothers, and infants younger than 2 months due to kernicterus risk. 1
When Single-Agent Therapy Is Sufficient
For most common infections, monotherapy with either agent is typically adequate:
For uncomplicated skin and soft tissue infections, clinical trials show equivalent cure rates between clindamycin (92.1%) and TMP-SMX (91.9%) when used as single agents, though clindamycin had lower recurrence rates (2.0% vs 7.1%). 4
For community-acquired MRSA skin infections, both agents perform similarly as monotherapy when combined with incision and drainage, with failure rates of 26% for TMP-SMX versus 25% for clindamycin. 5
Choice between single agents should depend on local resistance patterns, patient-specific factors including allergies, and the specific infection being treated. 1, 6