Acute methotrexate toxicity presenting as multiorgan failure and acute pneumonitis: A rare case report
A 48-year-old, male with a 2-year history of plaque psoriasis affecting limbs and trunk was advised 5 mg of oral MTX thrice weekly. However, accidentally he ingested three tablets daily (5 mg each) for 4 days i.e., total dose of 60 mg. A week later, he presented to the emergency department with nausea, vomiting and painful skin erosions over the trunk and intertriginous areas. He developed yellowish discoloration of urine along with low urine output. Three days back he developed fever with cough and respiratory distress.\nOn examination was icteric, tachycardic (HR = 110/ min), arterial blood pressure BP = 136/54 mmHg, and tachypnoeic (RR = 38/min). He was conscious and oriented. At admission, laboratory investigations revealed pancytopenia, other investigation on day 1 are listed in . Bilateral diffuse infiltrates seen on chest X-ray [], were believed to be due to pneumonia as his echocardiography and lower limb Doppler were all within normal limits.\nArterial blood gas analysis revealed hypoxemia with primary respiratory alkalosis. Diagnosis of acute MTX toxicity with multiorgan dysfunction was made. MTX was immediately discontinued. Intravenous folinic acid at dose of 15 mg was given 6 hourly (1 mg/kg). Subcutaneous granulocyte colony-stimulating factor (G-CSF) 350 μg was also given. In view of respiratory distress, patient was intubated and initiated on mechanical ventilation. As his urinary pH was 5.9, sodium bicarbonate 20 mEq/hr was added along with 1 l bolus followed by 100 ml/hr of normal saline to aid in alkalinization of urine (target urinary pH = 7.0).\nAfter collecting cultures, patient was started on broad spectrum empiric antibiotics (Meropenem and Teicoplanin) and antifungals (Fluconazole) in view of neutropenia. Within 24 hours the patient's urine output improved and after 48 hours his platelet and leukocyte count also started increasing. Within 72 hours, he was extubated and was transferred to ward in another 2 days. As there was no evidence of infection (cultures sterile and normal procalcitonin) antibiotics were stopped after 5 days. Serial clinical and laboratory parameters are shown in [].