Possible Interaction: Dextroamphetamine and Naloxone

“This effect was enhanced by subsequent systemic administration of D-amphetamine and blocked by previous treatment with naloxone.”

“Using perfused tissue slices, naloxone (10(-6)-10(-5) M) significantly attenuated the increase in [3H]DA release induced by d-amphetamine (10(-5) M) in both brain regions.”

“When the dose of d-amphetamine was increased to 3 mg/kg, naloxone (3 mg/kg) antagonized only the increase in rearing activity.”

“ NX can also significantly potentiate the central effects induced by DA agonists including DA agonist ( d-amphetamine ) induced 3H-dopamine release, and antagonize a number of the central effects elicited by DA release inhibiting agents.”

“In contrast, response rates were reduced at all doses of d-amphetamine tested in the presence of naloxone.”

“Thus, the interaction between naloxone and d-amphetamine is qualitatively different from the one between naloxone and the analgesics.”

“The locomotor stimulating effect of d-amphetamine in mice was counteracted by the administration of l-naloxone [(-)-naloxone], a known opiate receptor antagonist.”

“While NX had no effect on its own in either of these preparations, it was able to significantly enhance the release of DA induced by d-amphetamine.”

“It is concluded that antagonism between NAL and AMPH could be due: (1) to enkephalinergic control of dopamine regulated nigral efferents, (2) to an action on the thalamic structures responsible for the reciprocal control of the two nigrostriatal dopaminergic pathways.”

“ Naloxone was ineffective in blocking or reversing d-amphetamine inhibition of noradrenergic neuron activity.”