Moderate
Suspected
Description
Clindamycin may reduce renal tubular secretion of methotrexate, raising methotrexate levels and increasing the risk of haematological and GI toxicity.
Mechanism
Clindamycin can inhibit transporters involved in renal elimination of methotrexate (OAT1/OAT3), reducing clearance; additionally, antibiotic-mediated gut flora disruption alters the enterohepatic recycling of methotrexate.
Clinical Significance
Case reports describe pancytopenia and mucositis in patients receiving low-dose methotrexate after antibiotic therapy; routine monitoring is advised.
Management
Monitor full blood count and renal function closely; if high-dose methotrexate is planned, consider alternative antibiotics or delay antibiotic initiation.