Articles: analgesics.
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The effects of the major morphine metabolites, morphine-3-glucuronide and morphine-6-glucuronide, on nociception were assessed by the tail-flick, hot-plate and writhing tests in the rat. Morphine-3-glucuronide (M3G) 1.1 x 10(-9) mol (0.5 micrograms) or saline was injected intracerebroventricularly (i.c.v.) or intrathecally (i.t.) followed by a second injection of 2.0 x 10(-10) mol (0.1 microgram) or 2.0 x 10(-11) mol (0.01 microgram) morphine-6-glucuronide (M6G) 10 min later. Administration of M3G (i.c.v.) significantly attenuated the antinociceptive effects of M6G in the hot-plate test. ⋯ In animals receiving M3G there was a prevention or attenuation of the M6G induced depression of respiratory frequency, tidal volume and minute ventilation compared to control groups receiving M6G in combination with saline. These results show that M3G may functionally antagonize the central antinociceptive effects as well as the ventilatory depression induced by M6G. Interestingly, M3G was more potent in antagonizing the M6G-induced analgesia after i.t. administration than that after i.c.v. administration, which may suggest that the spinal cord is more sensitive to the non-opioid excitatory effects of M3G than supraspinal structures.
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Recent research into the mechanisms of pain and pain management and the development of new pharmacological agents have greatly increased the possibilities for preventing and treating postoperative pain in the pediatric patient. This article briefly reviews the physiology of pain and the measurement and assessment of pain, and then discusses in some detail the various modalities useful in treating pain in the pediatric patient during the perioperative period.
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J. Pharmacol. Exp. Ther. · Feb 1992
Spinal opioid delta antinociception in the mouse: mediation by a 5'-NTII-sensitive delta receptor subtype.
Previous studies from our laboratory have indicated that i.c.v. pretreatment of mice with the novel, selective opioid delta receptor antagonists, [D-Ala2,Leu5,Cys6]enkephalin (DALCE) and naltrindole-5'-isothiocyanate (5'-NTII), differentially antagonized the direct antinociceptive effects of [D-Pen2,D-Pen5]enkephalin (DPDPE) and [D-Ala2]deltorphin II (DELT). These findings, and others, suggested the existence of subtypes of opioid delta receptors which could be classified as activated by DPDPE and DALCE sensitive (delta 1 receptor), or selectively activated by DELT and 5'-NTII sensitive (delta 2 receptor). The present study has extended these observations to the characterization of delta-mediated antinociception effects of DPDPE and DELT after i.t. administration in mice using pretreatment with DALCE and 5'-NTII in order to selectively antagonize the delta subtypes. ⋯ DPDPE, DELT and DALCE were 19.0 (12.9-28.1), 19.3 (16.1-23.1) and 2.0 (1.4-3.0) nmol. The delta antagonist, N,N-diallyl-Try-Aib-Aib-Phe-Leu-OH (ICI 174,864) (where Aib is alpha-aminoisobutyric acid) blocked the antinociceptive effects of DPDPE and DELT, but not those of i.t. morphine or [D-Ala2,NMPhe4,Gly-ol5]enkephalin (DAMGO), indicating that the observed antinociceptive effects of DPDPE and DELT were delta mediated. Pretreatment 24 hr before testing with graded doses of i.t. 5'-NTII blocked the i.t. antinociceptive effects of DPDPE and DELT, although at least a 10-fold higher dose of 5'-NTII was needed to produce equivalent antagonism of DPDPE.(ABSTRACT TRUNCATED AT 250 WORDS)
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Pharmacology & toxicology · Feb 1992
Antinociceptive effects and central nervous system depression caused by oxycodone and morphine in rats.
Antinociception and central nervous system depression (CNSD) caused by intraperitoneal, intrathecal and subcutaneous administration of oxycodone or morphine were studied in a randomized and blind, saline controlled study in rats. Antinociception was assessed with the tail-flick and hot plate tests. CNSD was assessed by testing the corneal, placing and righting reflexes and with a 4-point catalepsy score. ⋯ In both nociceptive tests subcutaneously and intraperitoneally administered oxycodone was 2-4 times more potent than morphine, while intrathecal morphine was over 14 times more potent. CNSD was more profound with oxycodone than with morphine after intraperitoneal and subcutaneous administration, but was not observed after intratechal administration of either drug. Differences in opioid receptor affinities, liposolubilities and metabolism are discussed as possible explanations.
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Randomized Controlled Trial Comparative Study Clinical Trial
Halothane-morphine compared with high-dose sufentanil for anesthesia and postoperative analgesia in neonatal cardiac surgery.
Extreme hormonal and metabolic responses to stress are associated with increased morbidity and mortality in sick adults. We hypothesized that administering deep opioid anesthesia to critically ill neonates undergoing cardiac surgery would blunt their responses to stress and might improve clinical outcomes. ⋯ In neonates undergoing cardiac surgery, the physiologic responses to stress are attenuated by deep anesthesia and postoperative analgesia with high doses of opioids. Deep anesthesia continued postoperatively may reduce the vulnerability of these neonates to complications and may reduce mortality.