A case of pancytopenia secondary to low-dose pulse methotrexate therapy in a patient with rheumatoid arthritis and renal insufficiency

Fatal pancytopenia in a hemodialysis patient after treatment with low-dose methotrexate

We report a 56-year-old male hemodialysis patient who developed fatal pancytopenia after treatment with low-dose methotrexate for psoriasis and psoriatic arthropathy. Risk factors identified included impaired renal function, concurrent use of nonsteroidal anti-inflammatory drugs, low serum albumin, and relatively low serum folate level. Literature review found similar risk factors in 12 other cases. Therefore, methotrexate, even as a single dose, should not be used to treat rheumatic conditions in dialysis patients.

Drug dosing in chronic kidney disease

Patients with chronic kidney disease (CKD) are at high risk for adverse drug reactions and drug-drug interactions. Drug dosing in these patients often proves to be a difficult task. Renal dysfunction-induced changes in human pathophysiology regularly results may alter medication pharmacodynamics and handling. Several pharmacokinetic parameters are adversely affected by CKD, secondary to a reduced oral absorption and glomerular filtration; altered tubular secretion; and reabsorption and changes in intestinal, hepatic, and renal metabolism. In general, drug dosing can be accomplished by multiple methods; however, the most common recommendations are often to reduce the dose or expand the dosing interval, or use both methods simultaneously. Some medications need to be avoided all together in CKD either because of lack of efficacy or increased risk of toxicity. Nevertheless, specific recommendations are available for dosing of certain medications and are an important resource, because most are based on clinical or pharmacokinetic trials.