Effects of fluphenazine decanoate (a long-acting phenothiazine) on serum prolactin and amphetamine-induced behavioural changes.
A single injection of fluphenazine decanoate (FD) antagonized effects of acute d-amphetamine (2.5 mg/kg) for a variable period of time (4 to 28 days), depending upon the dosage of the neuroleptic used (2.5 or 5.0 mg/kg) and the behavioural parameter(s) monitored. Locomotion and rearing were antagonized for a longer duration than was sniffing. Normal locomotor response to amphetamine was attained 12 and 28 days following the administration of 2.5 and 5.0 mg/kg FD, respectively. However, the 2.5 mg/kg FD group displayed significantly more locomotor activity on days 20 and 24 post-treatment. A similar supersensitive response was not demonstrable with the higher dose of FD (5.0 mg/kg), or with the other behavioural measures. The prompt and pronounced elevation of serum prolactin returned to within the normal range by days 4 and 14, following administration of 2.5 and 5.0 mg/kg FD, respectively. These results indicate that the behavioural paradigm is more sensitive in monitoring the effects of FD and could serve as a useful model in investigating the dose- and time-related effects of other long-acting neuroleptics.
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004298:Dopamine / Q000502:physiology; D004347:Drug Interactions; D005476:Fluphenazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D011388:Prolactin / Q000097:blood*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D011388:Prolactin; D000661:Amphetamine; C011825:fluphenazine depot; D005476:Fluphenazine; D004298:Dopamine