Introduction: Methotrexate is considered a leading therapy for patients with rheumatoid arthritis. It is absorbed by the gastrointestinal tract and eliminated mainly by the kidneys, making renal impairment a risk factor for methotrexate toxicity. Adverse effects of methotrexate toxicity include high incidences of oral and gastrointestinal mucositis, which can weaken the mucosal barrier and lead to infection. Mucositis of the oral cavity and intestine may create entry points for opportunistic organisms, e.g., Candida albicans, resulting in disseminated disease. This can be quite severe, especially in immunocompromised patients, resulting in high morbidity and mortality Description: A 76-year-old man with a past medical history of hypertension, diabetes mellitus, end-stage renal disease, chronic heart failure, coronary artery disease, and rheumatoid arthritis (RA) presented to the ER with acute onset of shortness of breath, tongue swelling, oral bleeding, and throat pain. He had recently been prescribed low-dose methotrexate by his rheumatologist for worsening symptoms of his RA. In the ED was found to have appreciable tongue swelling, dyspnea, and tachypnea, and was intubated for threatened airway. Labs showed pancytopenia, hyperkalemia, and an anion gap metabolic acidosis. Treatment included dialysis, platelet transfusions, and empiric antibiotics and antifungal agents for positive blood cultures of Candida albicans. Over the next few days, his clinical course followed a stormy trajectory in the ICU, including escalation of pressors. Despite aggressive care, he remained in refractory septic shock, went into cardiac arrest, and unfortunately passed away Discussion: This case exemplifies the need for more research on management of patients with co-existing renal and rheumatological disorders. This combination limits treatment options in these patients and places them at increased susceptibility to toxic side effects from their treatments. Frequent lab monitoring of drug levels may be applied as an option to mitigate the risk of toxicity, but cannot eliminate it. Though impossible to account for every potential outcome, treatment options in patients with chronic illnesses with co-existing renal impairment must be carefully weighed out prior to initiation, especially when these treatments are long-term
FRIMERMAN et al. (Sun,) studied this question.