Tolerance of haloperidol catalepsy.
Haloperidol (0.75 and 1.5 mg/kg p.o.) was administered daily for 16 days to male Wistar rats. The animals received an acute injection of haloperidol (0.5-2.0 mg/kg i.p. or 1.0-4.0 mg/kg p.o.) and catalepsy was measured. After 16 days on haloperidol, all animals became tolerant to the drug, exhibiting decreased cataleptic response to haloperidol; the intensity of catalepsy returned to normal after an additional 16 days abstinence from the drug. In addition, a group of animals treated and tested daily for catalepsy demonstrated that the time course of tolerance development to haloperidol was biphasic, with a rapid phase (T1/2 = 2.5 days) and a slower phase (T1/2 = 5.5 days).
D000284:Administration, Oral; D000818:Animals; D002375:Catalepsy / Q000139:chemically induced*; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D006220:Haloperidol / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007274:Injections, Intraperitoneal; D008297:Male; D051381:Rats; D013997:Time Factors
D006220:Haloperidol