Two cases of severe neutropenia in patients on low-dose methotrexate and ceftriaxone.

Purpose: There are limited data on the effect of ceftriaxone on methotrexate clearance, with results of some studies indicating altered methotrexate pharmacokinetics with the administration of ceftriaxone. We describe 2 possible cases demonstrating an interaction between methotrexate and ceftriaxone, resulting in profound neutropenia.

Summary: The decision to continue methotrexate therapy in the setting of surgery or during treatment of an active infection continues to be a topic of debate due to perceived negative effects on the healing process.