Co-Trimazine is the combination of which two drugs?

• A. Trimethoprim and Sulfadiazine
• B. Trimethoprim and Sulfamethoxazole
• C. Amoxicillin and Clavulanic acid
• D. Ofloxacin and Rifampicin

Answer: (A)

Co-Trimazine pairs trimethoprim with sulfadiazine. This fixed combination exploits synergistic blockade of bacterial folate synthesis: sulfadiazine is a sulfonamide that inhibits dihydropteroate synthase, while trimethoprim inhibits dihydrofolate reductase. Blocking two steps in the same pathway produces a stronger antibacterial effect than either drug alone and helps reduce resistance. The other options are different drug combinations and do not carry the same brand name.