Articles: narcotic-antagonists.
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J. Am. Acad. Dermatol. · Oct 1999
Clinical TrialEfficacy and safety of naltrexone, an oral opiate receptor antagonist, in the treatment of pruritus in internal and dermatological diseases.
The perception of pruritus is modified by endogenous opiates via central opiate receptors in a histamine-independent manner. ⋯ The study suggests that oral opiate antagonists might be a well-tolerated and effective therapy for pruritic symptoms in many diseases.
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Pulmonary edema is a generalized descriptive term for the accumulation of fluid within the interstitium and/or the alveolar spaces of the lungs. This accumulation of fluid has a cause that may be termed cardiogenic or noncardiogenic. ⋯ Some occurrences of NCPE can be traced directly to the administration of anesthesia. For example, NCPE can result from upper airway obstruction or the administration of naloxone.
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Naunyn Schmiedebergs Arch. Pharmacol. · Oct 1999
Effects of continuous opioid receptor blockade on alcohol intake and up-regulation of opioid receptor subtype signalling in a genetic model of high alcohol drinking.
Effects of a continuous naloxone infusion via osmotic pumps on alcohol drinking and opioid receptor density and function in the high-drinking AA (Alko, Alcohol) rats were examined. AA rats were trained to drink 10% (v/v) ethanol in a 1-h limited access procedure and implanted with subcutaneous osmotic pumps delivering either saline, a low dose (0.3 mg/kg per hour), or a high dose (3.0 mg/kg per hour) of naloxone for 7 days. The pumps were then removed and alcohol, food and water intakes were measured for another 4 days. ⋯ A good correlation existed between ligand binding densities and G-protein activation for mu- and kappa-receptors in control and naloxone-treated brain sections. Furthermore, morphine-induced analgesia in a hot-plate test showed a leftward shift in the morphine dose-response curve after naloxone treatment. These results suggest that the usefulness of a chronic opioid antagonist dosing regime could be limited by nonspecific effects of the antagonist on ingestive behaviour, an up-regulation of opioid receptors with high antagonist doses, and the resulting supersensitivity to opioid agonists after the discontinuation of the treatment.
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Acta Anaesthesiol Scand · Aug 1999
Randomized Controlled Trial Clinical TrialKetamine antagonises alfentanil-induced hypoventilation in healthy male volunteers.
The effects of ketamine on respiration, alone, or in combination with opioids, have not been completely clarified. Both stimulant and depressant effects have been reported, as well as attenuation of opioid-induced hypoventilation at the expense of increased oxygen consumption. These conflicting results might partly be due to dose-dependent mechanisms. We have, therefore, determined the ventilatory effects of ketamine, in combination with alfentanil, using infusions to different pseudo steady-state concentrations. ⋯ In the dose range of interest for postoperative, intensive-care and pain-clinic settings, ketamine antagonises the resting hypoventilation induced by alfentanil.