A case of pancytopenia associated with concomitant use of methotrexate, lamotrigine and sulfamethoxazole/trimethoprim

Abstract Background Pancytopenia is a potentially life-threatening condition characterized by significant reduction in the three major blood cell lines. Medication induced pancytopenia is characterized by a decrease in all blood cell lines resulting from the bone marrow suppressive effects of medication(s). Case presentation We report the case of a Caucasian woman in her 80’s with a medical history significant for rheumatoid arthritis on long term methotrexate with previously normal blood cell counts who was hospitalized with pancytopenia after lamotrigine dose titration and a recent course of sulfamethoxazole-trimethoprim. Upon discontinuation of the offending medications, platelet transfusion and administration of leucovorin, pancytopenia resolved, and she was discharged. Conclusions This is the first reported case in the published literature to explore the combined hematologic adverse effects of the concomitant use of these agents in an older adult patient and underscores the importance of cautious prescribing and provider communication to prevent adverse drug effects in patients receiving methotrexate.