Possible Interaction: Chlorpromazine and Epinephrine

“A larger dose (9 mg/kg) of chlorpromazine slightly reduced the pressor effect of noradrenaline but caused a spectacular reversal of the pressor effect of adrenaline.”

“ Chlorpromazine was a remarkably potent antagonist (pA(2) approximately 14) of adrenaline and noradrenaline.”

“In the cat anaesthetized with chloralose small doses (1.8 to 4.5 mg/kg) of chlorpromazine greatly reduced or reversed the pressor effect of adrenaline but the pressor effect of noradrenaline was unaffected.”

“In addition, with the MyD patients, a significantly higher concentration of chlorpromazine and lignocaine was required to inhibit aggregation induced by a standard dose of adrenaline.”

“Psychological measurements by observers unaware of drugs given indicated that the anxiety‐arousing effects of epinephrine were reduced by chlorpromazine but that the anxiety‐like effects of yohimbine were potentiated.”

“The systolic pressor effects of epinephrine were reduced by chlorpromazine but to a lesser extent late in the 90 day period.”

“In man chlorpromazine and phenoxybenzamine have been shown to reduce the constrictor effects of adrenaline and noradrenaline in the hand (Ginsburg & Duff, 1956, 1958; Duff & Ginsburg, 1957).”

“ Chlorpromazine causes slow wave activity to become dominant in the spontaneous EEG and depresses the activating response evoked by auditory and sciatic nerve stimulation, direct stimulation of the bulboreticular formation, and epinephrine.”

“The chlorpromazine did reduce the magnitude of the pressor response to epinephrine , especially in patients under spinal anesthesia.”

“Courvoisier et al. demonstrated that chlorpromazine has adrenolytic properties, by blocking the pressor action of intravenous epinephrine and norepinephrine and causing a hypotensive effect similar to that seen with Dibenamine when large doses were used.”

“They demonstrated that chlorpromazine prevented the fibrillatory effect of epinephrine , l-norepinephrine and N-isopropyl-norepinephrine on the papillary muscle of the cat.”

“Hypotension was caused by a drug interaction between adrenaline and chlorpromazine through the activation of the β-adrenergic receptor and showed a dose-dependent effect.”

“ Chlorpromazine , amitriptyline and idazoxin inhibited larval metamorphosis induced by 10−4 M epinephrine.”

“ Chlorpromazine , when incubated with isolated adrenal cells , inhibited the ACTH-stimulated formation of cGMP and corticosterone production.”