Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030193 (pain)
 261,466 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thirty postoperative patients, after undergoing abdominal hysterectomy and standard general anesthesia, were randomly allocated to three groups and received, in the recovery ward, a continuous infusion of either pentazocine, piritramide, or ketamine. The patients rated their pain on a 15-cm visual analog scale. Patients in group 1 received pentazocine. Mean dosage was 0.12 mg/kg/hr on the day of operation, 0.1 mg/kg/hr on the first postoperative day, and only 0.07 mg/kg/hr on the second postoperative day. Pentazocine blood levels averaged 50 micrograms/L. Patients in group 2 received piritramide. Mean dosage was 0.038 mg/kg/hr on the day of operation, 0.024 mg/kg/hr on the first postoperative day, and 0.019 mg/kg/hr on the second postoperative day. Blood levels of piritramide were not determined because no satisfactory assay is available. Patients in group 3 received ketamine. Mean dosage was 0.32 mg/kg/hr on the day of operation, 0.28 mg/kg/hr on the first postoperative day, and 0.29 mg/kg/hr on the second postoperative day. Ketamine blood levels ranged between 120 and 180 micrograms/L. None of the three analgesics caused any important hemodynamic or respiratory side effects. Pentazocine and piritramide were more effective analgesics than ketamine was. Ketamine also had a higher incidence of side effects.
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PMID:Clinical experimental studies of postoperative infusion analgesia. 662 85

This study was undertaken with the objective of relieving pain which has been poorly understood and managed in peri-operative period specially in children. Here the analgesic efficacy of pentazocine was studied in 50 cases, aged between 5 and 9 years subjected to both major and minor surgeries. No premedication was given to assess the sole analgesic effect of the drug. Pentazocine was given during induction, dose being 0.5 mg/kg body weight intravenously. Subsequently small incremental doses were repeated after every 30-45 minutes during surgery. Satisfactory analgesia was obtained during intra- and postoperative period. No respiratory depression, no change in pulse, BP and no other complications were observed after administration of intravenous pentazocine.
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PMID:Clinical trial of pentazocine as analgesic in paediatric cases. 805 3

Pentazocine can be a useful analgesic agent for the management of acute dental pain. It has both central and peripheral opioid activity. In clinical trials, analgesic compounds containing pentazocine have been shown to effectively relieve moderate-to-severe pain. It is an appropriate analgesic for the codeine-sensitive patient. Because of a change in formulation, the potential for abuse has been minimized. Although there is a possibility that the drug may have a psychotomimetic effect, the incidence is low and should not preclude use. Analgesic compounds containing pentazocine are clinically appropriate for the management of surgically induced dental pain.
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PMID:Pentazocine analgesia: is there a niche for Talwin Nx? 826 39

The influence of timing of administration of preoperative pentazocine on pain and analgesic requirements after surgery was studied in 46 patients undergoing total abdominal hysterectomy. Twenty-three patients received thiamylal 5 mg.kg-1 on induction of anesthesia, followed by pentazocine 30 mg or 60 mg before surgical incision (group A). Twenty-three control patients received pentazocine 30 mg or 60 mg, 5 min after abdominal incision (group B). The visual analogue scales for pain 24 h after operation were 6.0 cm at 30 mg dose in group A or 5.3 cm at 60 mg dose in group A and 5.7 cm at 30 mg dose in group B or 4.7 cm at 60 mg dose in group B. There were no differences in the visual analogues scales. Pentazocine consumption in the first 24 h after surgery was 67.5 mg at 30 mg dose in group A or 52.5 mg at 60 mg dose in group A and 70.9 mg at 30 mg dose in group B or 51.8 mg at 60 mg dose in group B. We conclude that postoperative pentazocine consumption and pain scores are no different when pentazocine is given before or after skin incision for abdominal hysterectomy and that there is no clinically useful pre-emptive analgesic effect with these doses of pentazocine.
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PMID:[Pre-emptive analgesia from intravenous administration of opioid: no effect with pentazocine]. 875 79

Agonists at kappa-opioid receptors may preserve the analgesic properties of mu-opioidergic agonists while avoiding their major adverse effects. The present study was aimed to investigate the antinociceptive effects of the new kappa-opioid receptor agonist RP 60180. An experimental pain model was used based on specific pain stimuli and event-related potentials. Effects of RP 60180 were compared to placebo and to pentazocine that served as positive control. Twenty healthy male volunteers participated in a placebo-controlled, randomized, double-blind, five-way cross-over study. Single peroral doses of RP 60180 (0.1, 0.5, and 1.0 mg), pentazocine (50 mg), and placebo were administered. Pain was induced by means of short pulses of gaseous CO2 applied to the nasal mucosa. In response to these stimuli, chemo-somatosensory event-related potentials (CSSERP) and pain ratings were recorded. Maximum antinociceptive effects were observed 2 h after the administration of 1.0 mg of RP 60180 and 50 mg of pentazocine. This was shortly after RP 60180 had reached the maximum plasma concentration and when highest plasma concentrations of pentazocine were measured. Both RP 60180 and pentazocine reduced pain-related CSSERP amplitudes by approximately 40% at this time. Pentazocine tended to produce more side effects. These results indicate the potential therapeutic value of kappa-agonist analgesics.
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PMID:Antinociceptive effects of the kappa-opioid receptor agonist RP 60180 compared with pentazocine in an experimental human pain model. 919 45

The purpose of the present study was to determine whether electrical cortical stimulation (as a model of descending inhibitory control) could alter the electrophysiological and behavioral signs of a nociceptive response. The inhibitory cortical influence on the neuronal activity produced by nociceptive stimuli (the tooth pulp, C-fibers of afferent somatic nerves, cardiac afferents) was most marked during electrical stimulation the somatosensory (Sn and St) and fronto-orbital cortices. In chronic experiments, somatosensory cortical stimulation delayed the development of the deafferentation pain syndrome and reduced its intensity. The opioid mu-receptor agonists morphine and fentanyl potentiated the inhibitory action of the cortex on evoked neuronal activity. Pentazocine, a kappa-receptor agonist, was less effective. The opioid receptor blocker naloxone eliminated the effect of both cortical stimulation and opioid analgesics. The serotonin receptor blocker methisergide significantly decreased cortical action. Monoamine reuptake inhibitors (amitriptyline, imipramine, fluoxetine) potentiated the effect of cortical stimulation. Adrenergic, dopaminergic cholinergic, and GABA-ergic substances had a little effect. Among nonopioid analgesics, metamyzol and ketorolak only increased moderately descending cortical control.
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PMID:[The descending cortical control of nociceptive signals: the neurochemical mechanisms and pharmacological control]. 988 98

The antinociceptive effects of various mu opioids given p.o. alone and in combination with Delta-9-tetrahydrocannabinol (Delta9-THC) were evaluated using the tail-flick test. Morphine preceded by Delta9-THC treatment (20 mg/kg) was significantly more potent than morphine alone, with an ED50 shift from 28.8 to 13.1 mg/kg. Codeine showed the greatest shift in ED50 value when administered after Delta9-THC (139.9 to 5.9 mg/kg). The dose-response curves for oxymorphone and hydromorphone were shifted 5- and 12.6-fold, respectively. Methadone was enhanced 4-fold, whereas its derivative, l-alpha-acetylmethadol, was enhanced 3-fold. The potency ratios after pretreatment with Delta9-THC for heroin and meperidine indicated significant enhancement (4.1 and 8.9, respectively). Pentazocine did not show a parallel shift in its dose-response curve with Delta9-THC. Naloxone administration (1 mg/kg s.c.) completely blocked the antinociceptive effects of morphine p.o. and codeine p.o. The Delta9-THC-induced enhancement of morphine and codeine was also significantly decreased by naloxone administration. Naltrindole (2 mg/kg s.c.) did not affect morphine or codeine antinociception but did block the enhancement of these two opioids by Delta9-THC. No effect was seen when nor-binaltorphimine was administered 2 mg/kg s.c. before morphine or codeine. Furthermore, the enhancements of morphine and codeine were not blocked by nor-binaltorphimine. We find that many mu opioids are enhanced by an inactive dose of Delta9-THC p.o. The exact nature of this enhancement is unknown. We show evidence of involvement of mu and possibly delta opioid receptors as a portion of this signaling pathway that leads to a decrease in pain perception.
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PMID:Enhancement mu opioid antinociception by oral delta9-tetrahydrocannabinol: dose-response analysis and receptor identification. 1021 64

Clinical and experimental data indicate that the cerebral cortex plays an important role in pain perception and endogenous antinociceptive system function. Moreover, the enhancement of descending inhibitory cortical control may be involved in the mechanisms of analgetic effect of some agents. The present study was designed to investigate the effect of cortical electrical stimulation (as a model of descending inhibitory control) on the behavioral and electrophysiological signs of nociceptive response, decipher the mechanisms involved therein and evaluate the action of central analgesics (both opioid and non-opioid) on descending cortical control. In acute experiments in cats the inhibitory cortical influence on neuronal activity produced by nociceptive stimuli (electrical stimulation of tooth pulp, C-fibers of afferent somatic nerves, afferent cardiac structures) was most marked after stimulation of the first and second sensory and fronto-orbital areas. In chronic experiments on rats cortical stimulation reduced behavioral signs of visceral pain (writhing test) and also delayed the development of neuropathic pain syndrome along with lowering its intensity. Mu-opioid receptor agonists (morphine, fentanyl) potentiated the inhibitory cortical effect on the evoked neuronal activity. Pentazocine, which has pronounced kappa-receptor agonistic activity, was less effective. Naloxone eliminated the effects of both cortical stimulation and opioid analgesics. Serotonin receptor antagonist methysergide as well as p-chlorophenylalanine significantly decreased inhibitory cortical control and opioids effect. Monoamine re-uptake inhibitors with analgetic properties (imipramine, fluoxetine) potentiated the inhibitory effect of cortical stimulation. Adrenoceptor, dopamine, acetylcholine, GABA-receptor agents and antagonists of NMDA receptors had minor or no effect. Among non-narcotic analgesics, inhibitors of cyclooxygenase, metamysole and ketorolak increased only moderately the descending cortical control of nociception. Thus, the cerebral cortex is able to control the nociceptive processing in different pain syndromes (somatic, visceral or neuropathic pain). Opioidergic and serotonergic systems play the key role in this control. The effect over the cortical descending control is likely to be one of the components of the analgetic effect exerted by opioids and some other central analgesics.
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PMID:Pharmacological regulation of descending cortical control of the nociceptive processing. 1044 70

Pentazocine and cyclazocine are two benzomorphans that were synthesized by the late Sydney Archer in 1962. These benzomorphans were synthesized as part of an effort to develop analgesics with little or no abuse potential. Pentazocine is used as an analgesic, often in individuals who have sever pain or in those who have drug-abuse problems. Cyclazocine is a low-liability analgesic and potential therapeutic for the treatment of drug abuse. The risk of drug dependence is lower with the benzomorphans, which usually act as partial agonists at the mu opioid receptor and as kappa agonists. In an attempt to synthesize analogs of cyclazocine with increased bioavailability and varying kappa agonist and partial mu agonist properties, a series of 8-amino derivatives of cyclazocine were synthesized. These compounds were characterized in radioligand binding assays for their affinity and selectivity for the mu, delta, and kappa opioid receptors. Mouse antinociceptive tests were used to characterize the agonist and antagonist properties of each compound at the mu, delta and kappa receptors.
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PMID:Partial opioids. Medications for the treatment of pain and drug abuse. 1091 20

The present study was designed to investigate the antinociceptive interaction of a clinically used opioid, pentazocine which produces its analgesic effect mainly through kappa receptors, with some calcium channel blockers (CCBs, viz. Diltiazem, flunarizine, nimodipine and verapamil--each representing one chemical class) in formalin and tail flick tests in mice. All the CCBs, except verapamil, significantly inhibited the formalin-induced pain response in a dose-dependent manner. However, none of these drugs affected tail flick latency at any of the studied doses. Pentazocine showed a significant antinociceptive response in both pain models, although a high dose was required to increase the tail flick latency. Pretreatment with all CCBs, individually enhanced the analgesic effect of pentazocine in both formalin and tail flick tests. In the latter test of nociception, a per se ineffective dose of pentazocine, showed a significant analgesic response in presence of CCB dose which itself was not effective in the test. Chronic concomitant administration of diltiazem with pentazocine did not prevent the development of tolerance to the opioid compound. However, diltiazem when given in combination with pentazocine to pentazocine-tolerant animals, it effectively reversed the tolerance. Results of the study thus suggest that concomitant treatment with CCBs, irrespective of their chemical nature, not only potentiate the antinociceptive effect of pentazocine in opioid naive animals in both tonic and acute nociceptive tests but also reverse the pentazocine tolerance.
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PMID:Interaction of pentazocine with calcium channel blocking drugs during chemical and thermal pain in mice. 1094 12


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