Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
Massive overdosing or acute poisoning by Allopurinol has not been reported. Return to top
In mice the 50% lethal dose (LD50) is 160 mg/kg given intraperitoneally (i.p.) with deaths delayed up to five days and 700 mg/kg orally (p.o.) (approximately 140 times the usual human dose) with deaths delayed up to three days. In rats the acute LD50 is 750 mg/kg i.p. and 6000 mg/kg p.o. (approximately 1200 times the human dose). Return to top
In the management of overdosage there is no specific antidote for Allopurinol. There has been no clinical experience in the management of a patient who has taken massive amounts of Allopurinol. Return to top
Both Allopurinol and oxipurinol are dialyzable; however, the usefulness of hemodialysis or peritoneal dialysis in the management of an Allopurinol overdosage is unknown. Return to top
Adapted from the FDA Package Insert.