The duration of tolerance to the anorexigenic effect of amphetamine in rats.

Rats were given dl-amphetamine 16 mg/kg twice daily for 15 days. Complete tolerance to the anorexigenic effect of amphetamine developed from day 7--11. A single injection of 16 mg/kg amphetamine was given to the amphetamine pretreated rats and to saline pretreated controls at different time-points after withdrawal, and their food intakes were compared. Signs of tolerance were present in 16 but not 20 days after withdrawal.