Articles: narcotic-antagonists.
-
Randomized Controlled Trial Clinical Trial
The combination of low dose of naloxone and morphine in PCA does not decrease opioid requirements in the postoperative period.
The continuous infusion of low doses of naloxone has been reported to decrease postoperative opioid requirements and opioid side effects. However, there is no study that evaluates the effectiveness of the combination of a low dose of naloxone and morphine using patient-controlled analgesia (PCA). This prospective, randomized double-blind controlled study sought to determine if the combination of a low dose of naloxone and morphine in a PCA solution decreases postoperative opioid requirements and pain intensity. ⋯ The morphine+naloxone group had more treatment failures (P=0.0001), higher opioid requirements (P=0.0097), greater pain intensity (P=0.04), less pain relief (P=0.004), and less satisfaction (P=0.01) than the morphine group. The incidence of side effects was similar in both groups (P=0.3). Contrary to previous reports, adding low doses of naloxone to a morphine PCA solution increases opioid requirements and pain.
-
To review opioid dependence (OD) and its treatment. Pharmacologic treatments, including the use of buprenorphine/naloxone, are presented. Pharmaceutical care functions for outpatient OD treatment are discussed. ⋯ OD is a critical unmet health problem in the US. Buprenorphine combined with naloxone represents an innovative treatment for OD in outpatient settings. This new treatment has advantages over MMT.
-
Randomized Controlled Trial Clinical Trial
The use of nalmefene for intrathecal opioid-associated nausea in postpartum patients.
The aim of this study was to compare the severity of nausea and incidence of emesis in laboring parturients who received intravenous nalmefene or placebo following an intrathecal opioid (ITO). We randomly assigned 60 ASA class I or II multiparous women to receive nalmefene or placebo. Subjects received fentanyl, 25 micrograms, and morphine, 250 micrograms, intrathecally on request for analgesia. ⋯ There were no significant differences in age, weight, duration of labor, volume of intravenous fluids infused, time from last meal to delivery, or time from administration of the ITO to injection of the study drug. There were no significant differences in mean visual analog scale nausea scores or frequency of emesis for any time interval. Nalmefene, 20 micrograms, given intravenously within 30 minutes of vaginal delivery does not significantly reduce the nausea and vomiting associated with the use of ITOs for labor analgesia.
-
J. Pharmacol. Exp. Ther. · Feb 2002
Paradoxical effects of the opioid antagonist naltrexone on morphine analgesia, tolerance, and reward in rats.
Opioid agonists such as morphine have been found to exert excitatory and inhibitory receptor-mediated effects at low and high doses, respectively. Ultra-low doses of opioid antagonists (naloxone and naltrexone), which selectively inhibit the excitatory effects, have been reported to augment systemic morphine analgesia and inhibit the development of tolerance/physical dependence. This study investigated the site of action of the paradoxical effects of naltrexone and the generality of this effect. ⋯ The potential of naltrexone to influence morphine-induced reward was also investigated using a place preference paradigm. Systemic administration of ultra-low doses of naltrexone (16.7, 20.0, and 25.0 ng/kg) with morphine (1.0 mg/kg) extended the duration of the morphine-induced conditioned place preference. These effects of naltrexone on morphine-induced reward may have implications for chronic treatment with agonist-antagonist combinations.