Painful stimuli are known to engage an endorphin analgesic system that can be reversed by the opiate antagonist, naloxone. Naloxone, then, should increase the effectiveness of aversive unconditioned stimuli (USs) in Pavlovian fear conditioning. Consistent with this hypothesis, naloxone administered during the acquisition of conditioned suppression in rats enhanced posttrial suppression and prec...

Stressful stimuli, electric footshock (FS), immobilized-water immersion (IW), and cold-water swimming (CWS), produced analgesia and prolonged the pentobarbital hypnosis as well as morphine and clonidine. Naloxone completely antagonized the analgesic effects of morphine and FS and partially that of IW; however, that of clonidine and CWS were not reversed by naloxone. Naloxone eliminated the hypn...

[(3)H]Naloxone, a potent opiate antagonist, binds stereospecifically to opiate-receptor sites in rat-brain tissue. The binding is time, temperature, and pH dependent and saturable with respect to [(3)H]naloxone and tissue concentration. The [(3)H]naloxone-receptor complex formation is bimolecular with a dissociation constant of 20 nM. 15 Opiate agonists and antagonists compete for the same rece...

A mixture of acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride is used for the symptomatic treatment of common cold. In this study, a derivative spectrophotometric method based on zero-crossing technique was proposed for simultaneous determination of acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride. Determination of these drugs was perf...

A highly sensitive method was developed to measure naloxone and its metabolite nornaloxone in human plasma, urine, and human liver microsomes (HLM). Naltrexone-d(3) and oxymorphone-d(3) were used as respective internal standards. Solid-phase extraction, using mixed mode extraction columns and 0.1 M phosphate buffer (pH 5.9), was combined with high-performance liquid chromatography interfaced by...

Sows (N = 16) were infused intravenously for 8 h with saline or naloxone (200 mg/h) or their litters were transiently weaned for 8 h. Before infusion, 200 mg naloxone were administered to elevate quickly concentrations of naloxone. Blood samples were collected from sows at 15 min intervals for 24 h, beginning 8 h before and continuing until 8 h after imposition of treatments during the middle 8...

BACKGROUND Naloxone is standard medication for the treatment of heroin intoxications. No large-scale studies have yet been carried out to determine its toxicity in heroin intoxications. METHODS We have undertaken an investigation as to the frequency, type and degree of severity of complications attributable to naloxone administration. Subjects treated between 1991 and 1993 with naloxone for i...

The effects of the opiate antagonist naloxone on electrophysiological measures of human selective attention were examined utilizing a paradigm which dissociates selective information processing from any concurrent processes of general arousal that may be present. Subjects were injected with naloxone (2 mg, i.v.) or placebo prior to performing a three-channel selective listening task. The measur...

INTRODUCTION Naloxone's use in cardiac arrest has been of recent interest, stimulated by conflicting results in both human case reports and animal studies demonstrating antiarrhythmic and positive ionotropic effects. We hypothesized that naloxone administration during cardiac arrest, in suspected opioid overdosed patients, is associated with a change in cardiac rhythm. METHODS From a database...

BACKGROUND Naloxone has been evidenced widely as a means of reducing mortality resulting from opiate overdose, yet its distribution to drug users remains limited. However, it is drug users who are most likely to be available to administer naloxone at the scene and who have been shown to be willing and motivated to deliver this intervention. The current study builds on a national training evalua...