“In the presence of caffeine, THP inhibited catalepsy intensity with an ED(50) of 0.19 mg/kg, and prolonged the latency with an ED(50) of 0.30 mg/kg.”
“In these animals, caffeine was still able to enhance the anticataleptic actions of THP , suggesting that repeated administration of 1 mg/kg caffeine does not induce tolerance to the synergism with anticholinergics.”
“The synergism was more evident when THP was administered at subthreshold doses that were unable to modify haloperidol-induced catalepsy when applied alone, but produced a clear inhibition of catalepsy when injected with caffeine.”
“To assess whether repeated administration of caffeine could induce tolerance to the synergism with THP , a group of rats was pretreated with three daily doses of caffeine (1 mg/kg) for seven days, and the catalepsy test was performed on the eighth day.”