Chronic phenytoin and the stereotyped motor response induced by 5-methoxy-N,N-dimethyltryptamine in rats.
Brain research February 11, 1985 R Lalonde, M I Botez 1 citation
Long-term administration of phenytoin (PHT) to male rats for 20 consecutive days reduced the intensity of a stereotyped motor response induced by the serotonin agonist 5-MDMT at 3 mg/kg when tested on day 21, but this effect was absent by day 28. A single injection of PHT did not alter the motor response. The authors suggest that PHT increases the functional availability of serotonin before its receptors, leading to serotonin receptor subsensitivity.