Articles: narcotic-antagonists.
-
We have demonstrated that pre-administered RB101 (40 mg/kg, i.v.), a mixed inhibitor of enkephalin-catabolizing enzymes, decreased spinal c-Fos expression induced 1 h and 30 min after intraplantar (i.pl.) carrageenin (41% reduction, p<0.01). These effects were completely blocked by pre-administered beta-funaltrexamine (10 mg/kg, i.v., 24 h prior to stimulation), a selective long-lasting mu-opioid receptor antagonist. In conclusion, these results clearly demonstrate that the effects of endogenous enkephalins on noxiously evoked spinal c-Fos expression are essentially mediated via mu-opioid receptors.
-
J Neurosurg Anesthesiol · Jul 1999
Comparative StudyHeart rate variability and plasma catecholamines in patients during opioid detoxification.
It has been shown that rapid opioid detoxification is associated with increased sympathetic activity (SYMP) and plasma catecholamines. Heart rate (HR) variability may provide a noninvasive method of evaluating withdrawal and sympathetic activation caused by the reversal of opioid binding in patients who are opioid dependent. The purpose of this study was to evaluate the relationship between HR variability and plasma catecholamines during opioid detoxification. ⋯ Plasma norepinephrine and epinephrine as well as SYMP increased 300 to 400% (P < .05) during naltrexone treatment in opioid-dependent patients, and the time to peak increase in plasma norepinephrine correlated with the increase in SYMP (r = 0.89, P < .01). These results confirm that opioid detoxification increases plasma catecholamines and SYMP in a similar manner. HR rate variability may provide a low-cost real-time noninvasive method of evaluating the reversal of opioid binding in opioid-dependent patients.
-
Respiratory depression secondary to morphine intoxication occurred in an elderly patient with chronic renal failure (CRF). It was reversed with a continuous infusion of naloxone. Approximately 11 hours after the infusion was discontinued, the patient relapsed into respiratory depression consistent with opioid intoxication. ⋯ Serum naloxone concentrations measured after the end of the infusion suggest that the drug's pharmacokinetics were significantly altered. Further research is necessary to characterize pharmacokinetic changes that occur in CRF. In the absence of this information, similar patients should be closely monitored for relapse of respiratory depression after naloxone is discontinued.
-
Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Double-blind, randomized study of nalmefene and naloxone in emergency department patients with suspected narcotic overdose.
To compare the efficacy, safety, and withdrawal symptoms in emergency department patients with suspected narcotic overdose treated with nalmefene, an opioid antagonist with a 4- to 10-hour duration of action, with those treated with naloxone. ⋯ In this study of patients with varied potential causes of altered consciousness, nalmefene (1 mg and 2 mg) and naloxone (2 mg) appeared to be efficacious, safe, and to yield similar clinical outcomes.
-
Comparative Study
Are heroin overdose deaths related to patient release after prehospital treatment with naloxone?
Naloxone is frequently used by prehospital care providers to treat suspected heroin and opioid overdoses. The authors' EMS system has operated a policy of allowing these patients, once successfully treated, to sign out against medical advice (AMA) in the field. This study was performed to evaluate the safety of this practice. ⋯ Giving naloxone to heroin overdoses in the field and then allowing the patients to sign out AMA resulted in no death in the one-year period studied. This study did not evaluate for return visits by paramedics nor whether patients were later taken to hospitals by private vehicles.