Which other drug, besides methotrexate, can cause a folate deficiency?

Bactrim, which is a combination of trimethoprim and sulfamethoxazole, can cause folate deficiency due to its action on folate metabolism. Trimethoprim specifically inhibits dihydrofolate reductase, an enzyme crucial for the synthesis of tetrahydrofolate, the active form of folate. This inhibition leads to decreased levels of folate in the body, which is essential for DNA synthesis and cellular division.

In contrast, other options such as amoxicillin, azithromycin, and doxycycline do not have a significant effect on folate metabolism. Amoxicillin is a penicillin derivative that works by inhibiting bacterial cell wall synthesis; azithromycin is a macrolide antibiotic that inhibits bacterial protein synthesis; and doxycycline is a tetracycline antibiotic also inhibiting protein synthesis. None of these medications interfere with folate metabolism in a way comparable to Bactrim or methotrexate. Therefore, Bactrim is the appropriate choice for a drug other than methotrexate that can cause folate deficiency.