Possible Interaction: Dextroamphetamine and Pimozide

“ d-Amphetamine and pimozide , when administered alone, produced significant and opposite effects on ratings of Elation and Vigor, as well as on psychomotor performance and physiological measures.”

“Although higher doses of pimozide may be needed to antagonize the euphorigenic effects of d-amphetamine , these results raise the possibility that the role of dopamine in the subjective effects of stimulants may be more complex than initially appreciated.”

“ Pimozide did not produce any effects when administered alone and produced inconsistent effects on responses to d-amphetamine.”

“Ten subjects received single oral doses of d-amphetamine (0, 10, 20 mg) 2 hours following pretreatment with pimozide (0, 1, 2 mg).”

“Improvement in negative symptoms while on d-amphetamine correlated significantly with subsequent improvement in the same negative symptoms while on pimozide.”

“Thirty schizophrenic patients received intravenous dextro-amphetamine while on and off pimozide.”

“Acute behavioral response to 20 mg of dextroamphetamine (intravenous) predicted fourth-week antipsychotic response to double-blind pimozide treatment.”

“In ten of 30 schizophrenic patients treated with pimozide for five weeks, 20 mg of dextroamphetamine sulfate induced an increase in psychosis.”

“Abstract Pretreatment with pimozide (mean dose = 13 mg/day) blocked the effect of d-amphetamine (20 mg base, administered by intravenous bolus infusion at 0815) on all-night EEG sleep patterns in seven hospitalized psychiatric patients.”

“Without treatment with pimozide, d-amphetamine significantly reduced duration of total sleep, REM and nonREM sleep, Stage I, and Stage II.”

“A decrease in DA receptor activity, achieved by pimozide pretreatment, abolished the effect of d-amphetamine on lordosis behavior, but the effect of l-amphetamine was only slightly diminished and the action of fenfluramine and p-chloroamphetamine was unaffected.”

“On the other hand, both l- and d-amphetamine-induced stereotype activity was prevented by pimozide treatment.”

“Acute pretreatments with the anti-psychotic dopamine blockers haloperidol and pimozide block stereotypy induced by both phenylethylamine and d-amphetamine , whereas antipsychotics with fewer extrapyramidal effects, thioridazine and clozapine, preferentially block phenylethylamine-evoked behavior.”

“The capability of the rating scale to assess antagonism of d-amphetamine by pimozide suggested that this scale may be a useful quantitative measure of neuroleptic activity of drugs.”

“Improvement in negative symptoms while on d-amphetamine correlated significantly with subsequent improvement in the same negative symptoms while on pimozide.”

“Thirty schizophrenic patients received intravenous dextro-amphetamine while on and off pimozide.”