Antimony excretion in a patient with renal impairment during meglumine antimoniate therapy

Meglumine antimoniate was administered to a patient with visceral leishmani asis with normal renal function. Soon after the first intramuscular adminis tration of meglumine antimoniate 20 mg/kg, equivalent to 510 mg antimony (S b), the patient developed septic shock with oliguria. Creatinine clearance decreased to 23 ml/minute. Treatment was discontinued, and Sb urinary excre tion was measured. After the initial dose, 500.25 mg Sb was recovered in ur ine over 8 days, corresponding to 98% of the amount of Sb given intramuscul arly (66% eliminated within first 48 hrs). Nine days after the dose, meglum ine antimoniate was reintroduced at a dosage of 11.7 mg/kg (equivalent to 3 00 mg Sb) every 48 hours with good tolerance. At that time creatinine clear ance had returned to 87.8 ml/minute. By day 14 of therapy the interval was reduced to daily administration of the same dose; the dosage was increased to 16.6 mg/kg/day (equivalent to 425 mg Sb) from day 17 to day 31. The pati ent eventually completely recovered and was discharged with normal renal fu nction. Although no specific guidelines exist for dosage adjustment in rena l failure, monitoring of Sb urinary excretion indicates that the kidneys ar e the almost exclusive route of elimination.