Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ANALGESICS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources

The analgesic activity of calcitonin and the central serotonergic system.

The effect of peripherally administered cyproheptadine or reserpine and the administration of 5,7-dihydroxytryptamine (5,7-DHT) in the nucleus raphe dorsalis on the analgesic activity of salmon calcitonin (sCT) injected into the lateral ventricle were investigated in male rats. Cyproheptadine or reserpine, given respectively 30 min or 24 h before the peptide, completely abolished the analgesic activity at all the times studied. However, when reserpine was given before the peptide it increased the effect of sCT at 30 (P less than 0.01), 60 (P less than 0.001), 120 (P less than 0.01) and 180 (P less than 0.01) min. 5,7-DHT injected in the nucleus raphe dorsalis 15 days before the peptide led to complete abolition of the analgesic activity. If neurotoxin was injected 4 days before sCT, the effect of the peptide was significant (P less than 0.05) only at 60 min. The results obtained confirm that the analgesic activity of sCT may involve central serotonergic pathway(s), and that the midbrain raphe nuclei 5-HT content is an important focus for this activity.

5,7-Dihydroxytryptamine↗

Peripheral analgesic action of clonidine: mediation by release of endogenous enkephalin-like substances.

Clonidine analgesia was tested on the hyperalgesia induced by intraplantar injection of prostaglandin E2 or carrageenin. The antinociceptive effect of clonidine was dose-dependent and was abolished by local administration of the selective alpha 2-adrenoceptor blocker, yohimbine or of the opioid antagonists naloxone or quaternary nalorphine. St-91, a clonidine analog which does not cross the blood-brain barrier also promoted significant antinociception. Repeated administration of drugs possessing a central mechanism of analgesic action leads to the development of tolerance in this test. Significant analgesic tolerance was observed following repeated (5 days) morphine (8 mg/kg) or high doses of clonidine (0.5 mg/kg). In contrast, no tolerance was detected to the analgesic effect of low doses of clonidine (0.15 mg/kg) or of St-91 (0.5 mg/kg). These results suggest that, in addition to its central analgesic action, clonidine can induce peripheral antinociception by an alpha 2-adrenoceptor-mediated local release of enkephalin-like substances.

Analgesics↗

Characterization of the analgesic activity of ketorolac in mice.

The spectrum of analgesic activity of ketorolac tromethamine was evaluated with mice exposed to the hot-plate, tail-flick and writhing tests. Morphine and indomethacin were used as representative opioid and non-steroidal analgesics respectively. Ketorolac in doses of 5 or 7.5 mg/kg i.p. was active as an analgesic in all three of the procedures. In each case, naloxone (0.5 mg/kg i.p.) significantly decreased the analgesic activity of ketorolac. It was suggested that ketorolac might act in part by causing the release of endogenous opioids.

Analgesics↗

Patients' night-time pain, analgesic provision and sleep after surgery.

One hundred patients were interviewed about their experiences of pain and sleep following abdominal surgery. This information was supplemented by data on analgesic provision which were gathered from medication charts. Pain was the most commonly reported cause of night-time sleep disturbance and analgesics helped more patients to get back to sleep than any other intervention. About half of the patients felt that pain was worse at night than during the day. An examination of patterns of analgesic provision revealed that the number of doses given peaked at two points during the 24-hour cycle. The highest numbers of doses were given between 8 a.m. and 12 noon and 8 p.m. and 12 midnight. Fewer doses were given at night, between midnight and 4 a.m. Analgesic provision at night, therefore, did not appear to be explicitly related to need. The assessment and control of post-operative pain at night requires further attention in order to optimize pain control and promote sleep.

Abdomen↗

Sites of analgesic action of dynorphin.

Analgesic effects of dynorphin and dynorphin-(1-13) injected into various regions of the CNS of rats were investigated using the tail pinch method. Dynorphin and dynorphin-(1-13) produced a dose-dependent analgesic effect when injected into the third ventricle (3rd vent.) or the nuclei reticularis gigantocellularis and paragigantocellularis (NRGC-NRPG) and the analgesic activity of dynorphin was 3 to 5 times more potent than that of dynorphin-(1-13). These peptides in higher doses elicited transient "barrel-rolling" and rigidity in behavior. On the other hand, when injected intrathecally, dynorphin exerted an analgesia accompanied by paralysis of hindlimbs which were long lasting. But its analgesic activity was less effective as compared with the 3rd vent. and NRGC-NRPG injections.

Analgesia↗

Analgesic abuse nephropathy.

Analgesic abuse nephropathy is seldom considered as a cause in patients presenting with chronic renal disease. In a three-year period 450 patients were seen with chronic renal failure. Of these 103 had interstitial renal disease as the cause of their failure. Twenty of these 103 were due to chronic analgesic abuse, which indicates that need for a greater awareness of this problem. The spectrum of clinical and roentgenographic aspects of analgesic abuse nephropathy are discussed. What constitutes analgesic abuse, helpful clinical findings, frequency of other medical illnesses, and the low incidence of documented renal infection prior to onset of renal failure are discussed. Intravenous pyelographic findings related to visualization, renal size, corticomedullary margins and pelvicalyceal changes are also discussed and demonstrated.

Analgesics↗

III - Prostaglandin hyperalgesia: relevance of the peripheral effect for the analgesic action of opioid-antagonists.

Morphine injected into the rat cerebral ventricles had a marked analgesic effect, while no effect was observed with pentazocine and naloxone or nalorphine caused a strong hyperalgesia. Administered systemically (IP) naloxone and nalorphine caused a transitory analgesia followed by a long lasting hyperalgesic effect; morphine and pentazocine showed only an analgesic effect. It was concluded that the site of analgesic action of opioid-antagonists is peripheral rather than central. The peptidase-resistant enkephalin-analog, BW 180c, which does not cross the blood brain barrier, caused a marked analgesia by IP administration to paws made hyperalgesic by PGE2 or carrageenin. It is suggested that agents derived from morphine, morphine-antagonists, enkephalins or cGMP devoid of central effect but having a strong peripheral effect may constitute a new class of safer analgesics.

Analgesics↗

Genetic factors in conditioned tolerance to the analgesic effects of etonitazene.

Tolerance to the analgesic effects of opioids have been reported to include unconditioned (physiological) and conditioned (associative) components. The purpose of the current study was to investigate the genetic and environmental factors important in the development of tolerance by using three inbred strains of mice with varying opiate receptor concentration and acute behavioral response to opioids: C57BL/6J, CXBK/ByJ, and CXBH/ByJ mice. Each strain was divided into three groups; each group received two injections per day as part of the tolerance development procedure. One group of each strain was administered an opioid (etonitazene) specifically paired with the testing room and a second injection of saline in the home colony (paired). The second group of each strain was administered saline in the testing room and etonitazene in the home colony (unpaired). A third group of each strain was administered saline in both the testing room and home colony (control). Etonitazene and saline were administered in this manner for 4 days. On day 5, animals were tested for hot-plate analgesic response following administration of etonitazene. There was a significant effect of treatment condition (paired, unpaired, control) on etonitazene-induced analgesia. In all strains, only the paired treatment condition demonstrated tolerance to the analgesic effects of etonitazene compared to the control groups. There was no significant effect of genotype or a genotype x condition interaction. Thus, genotype significantly affects the acute analgesic effects of opioids but did not affect the development of conditioned tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)

Analgesics↗

Strain differences in the analgesic and reinforcing action of morphine in mice.

The analgesic and reinforcing effects of morphine were compared in four strains of mice (C57BL/6, BALB/c, DBA, CBA). The analgesic action of morphine was measured in tail immersion (49 degrees C), hot plate (60 degrees C), and tail clip (four-point scale of nociceptive response) tests. The reinforcing action of morphine was studied in i.v. self-administration and conditioned place preference techniques. The results demonstrate strain differences in the analgesic and reinforcing action of morphine in mice. The relative rank order of the strains varied for the several tests as well as for the morphine effects. The lack of correlation between analgesic and reinforcing action of morphine in inbred strains supports the conclusion that analgesia and reinforcement are separate processes with different genetic control.

Analgesics↗

Sites of analgesic actions of kyotorphin and D-kyotorphin in the central nervous system of rats.

Kyotorphin(KTP) and its analog D-kyotorphin(D-KTP) which is resistant to enzyme degradation produced dose-dependent analgesic effects in the tail-pinch test when applied locally to the periaqueductal gray (PAG), nucleus reticularis paragigantocellularis(NRPG) and lumbosacral subarachnoid space(LSS) near the spinal dorsal horn in rts. ED50 values of both dipeptides at the PAG, NRPG and LSS were: 59.0, 105 and 52.6 micrograms/rat for KTP, and 6.2, 8.8 and 10.6 micrograms/rat for D-KTP, respectively. Pretreatment with naloxone(1 mg/kg s.c.) significantly inhibited the analgesic effects of KTP and D-KTP at the PAG and LSS but not at the NRPG. Simultaneous administration of bestatin (2.5 or 50 micrograms) with KTP enhanced the analgesic effect of KTP in the PAG and LSS but not in the NRPG. These findings suggest that the analgesic actions of KTP and D-KTP result from two different mechanisms, 1)enkephgalin-releasing mechanism in the PAG and spinal dorsal horn, and 2)a mechanism without involvement of enkephalin-releasing actions in the NRPG.

Analgesics↗

Simple procedure for measuring the pharmacodynamics and analgesic potential of lipoxygenase inhibitors.

A model is described for determining the pharmacodynamics of inhibitors of arachidonate metabolism in mice. Bioavailability and selectivity were assessed by ex vivo RIA of TXB2, LTB4, and 12-HETE from ionophore-challenged blood. Inhibition of LTB4 and 12-HETE was measured using a single LTB4 RIA, following extraction and separation of these eicosanoids from plasma. Separation on cyanopropyl mini-columns yielded hexane/ether and methanol fractions, which contained 12-HETE and LTB4, respectively. Analgesic efficacy was measured by inhibition of phenylbenzoquinone-induced abdominal constriction. The NSAIDs, indomethacin ibuprofen, flurbiprofen, and benoxaprofen, were analgesic and selective cyclo-oxygenase inhibitors. BW775C was also analgesic, but inhibited cyclo-oxygenase, 5-lipoxygenase and 12-HETE formation. Other in vitro 5-lipoxygenase inhibitors, NDGA, quercetin, and nafazatrom, were inactive in vivo, although NDGA reduced abdominal constrictions. The results indicate that this model has utility in determining the mechanism/selectivity of action and analgesic potential of 5-lipoxygenase inhibitors.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗

Linear and cyclic beta-casomorphin analogues with high analgesic activity.

We investigated the antinociceptive efficacy of casomorphin (CM) derivatives using the vocalization test. Male Wistar rats received chronic microcannulae into the right lateral ventricle. One week later we examined the analgesic effect of CM derivatives 10, 30, 60, and 90 min after intraventricular injection (5 microliters). The analgesic effect was calculated as the individual percent increase in the pain threshold and was compared to controls (saline treatment). The substitution of D-lysine and D-ornithine in position 2 in connection with a cyclization through ring closure of the 2 position side chain amino group to the C-terminal glycine-COOH group resulted in high analgesic potency. The substitution of D-Pro4 was without any effect in the ineffective linear derivatives and decreased the effectiveness in the highly effective cyclic derivatives. The cyclic [D-Orn2]CM-5 and the cyclic [D-Lys2]CM-5 are the CM derivatives with the highest antinociceptive activity. The cyclic [D-Orn2]CM-5 is greater than 1000 times more effective than morphine. We conclude, on the basis of studies of receptor binding and in vitro investigations, that mu receptor activity alone is not responsible for the analgesic activity. The delta receptor and possibly also the kappa receptor could modulate the nociceptive effectiveness.

Amino Acid Sequence↗

Graphical analysis of multivariate pain data in analgesic trials.

In order to compare analgesic treatments effectively one must measure pain over time. In a single-dose clinical analgesic trial one typically obtains repeated pain measurements from each patient during a relatively short period (4-6 hours). Such measurements constitute multivariate data, which are usually reduced by simple addition to a single derived pain measure for analysis of between-treatment differences. In this article we consider graphical procedures for the display of multivariate, clinical analgesic data. The first of these are the traditional time-effect curves, with added "standard error bars." We also examine a multivariate display, the biplot, which is based on principal component analysis. This technique provides a representation of the raw pain scores at each time of measurement by a vector originating from the origin of a two-dimensional graph. The multivariate pain scores of individual patients are summarized by points on the graph. Differences in pain scores over time (or between treatment groups) may be examined by relating points (or ellipses representing treatment groups) to different vectors. Using actual data from a postsurgical analgesic trial, we compare the two approaches and show that the multivariate approach is a useful addition to the standard technique for display of such data.

Analgesics↗

Involvement of biogenic amines with the mechanisms of novel analgesics.

The analgesic activity of the kappa opioid agonist, U-50,488H, was markedly antagonized by pretreatment with reserpine, p-chlorophenylalanine, and ketanserin. Likewise, analgesic doses of U-50,488H enhance serotonin metabolism. These results suggest that kappa analgesia requires serotonin acting through 5-HT2 receptors. The non-opioid analgesic, nefopam HCl, though a blocker of biogenic amine uptake, displays an analgesic spectrum of action more similar to that of amphetamine than that of the tricyclic antidepressants or serotonin uptake blockers. Likewise p-chlorophenylalanine and ketanserin do not block nefopam analgesia nor do naloxone, atropine, yohimbine, propranolol or haloperidol. However, as reserpine does block nefopam analgesia, biogenic amines acting at other receptors may be involved. The observation that m-tyrosine causes behavioral effects similar to high doses of nefopam suggested that they might be acting through similar mechanisms. However, although m-tyrosine causes analgesia, it is blocked by yohimbine. This suggests that alpha2-adrenoreceptors are involved in m-tyrosine analgesia and that it differs in mechanism from nefopam analgesia.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

Patterns of postoperative analgesic use with adults and children following cardiac surgery.

The postoperative prescription and administration of analgesics following cardiac surgery for 50 children were compared with those of 50 adults. Six children were the only patients in the sample who were prescribed no postoperative analgesics. Overall, children were prescribed significantly fewer potent narcotics. The administration data revealed even more pronounced group differences. During the observation period, children received 30% of all analgesic administrations while adults received 70%. Some possible reasons for these age differences in analgesic usage are presented, and implications regarding the adequacy of postoperative pain control in children are discussed.

Adolescent↗

Clinical analgesic assay of repeated and single doses of heroin and hydromorphone.

A direct comparison of the analgesic activities of heroin and hydromorphone was carried out in cancer patients with postsurgical pain. Intramuscular doses of 5 and 10 mg of heroin were compared with 1 and 2 mg of hydromorphone in a randomized, double-blind, 4-point parallel group assay. Design innovations in the study provided that about half the patients would receive prior repeated doses of the same drug as the test medication, and half would receive the alternate medication. Both test drugs were found to be potent, relatively short acting analgesics with similar profiles of action. Hydromorphone was about 5 times as potent as heroin on a milligram basis. The comparison of those patients who had repeated doses of the same treatment prior to the test dose and those who had repeated doses of the alternate drug demonstrated no significant effect on the relative potency estimates. Side effect occurrence was similar for both drugs, with sleepiness the most prominent effect. The study supports the view that hydromorphone and heroin produce similar clinical effects, and that either drug may adequately substitute for the other. Covariate analysis indicated that time since last analgesic was positively related to analgesia, and amount of prior opioid had a negative relationship. To a lesser extent, increase in patient age was associated with an increase in analgesic scores. Taking these covariates into account served to increase the sensitivity of the analysis.

Affect↗

Celiac plexus block versus analgesics in pancreatic cancer pain.

Twenty pancreatic cancer patients were studied to assess the effectiveness and duration of celiac plexus block compared to traditional treatment with analgesics by considering the previous and subsequent consumption of narcotics until their death. After 1 week of therapy with NSAID-narcotic sequence according to the WHO method, 10 patients were continued on this treatment, while the other 10 patients underwent celiac plexus block. Subsequently analgesics were administered as in the patients not treated by the block. A visual analogue score and opioid consumption were used to calculate the effective analgesic dose at weekly intervals until death. Celiac plexus block made pain control possible with a reduction in opioid consumption for a mean survival period of about 51 days. Administration of only analgesics resulted in an equal reduction in VAS pain score until death, but with more unpleasant side effects than when using celiac plexus block.

Adult↗

The utility of excitatory amino acid (EAA) antagonists as analgesic agents. II. Assessment of the antinociceptive activity of combinations of competitive and non-competitive NMDA antagonists with agents acting at allosteric-glycine and polyamine receptor sites.

The present study examined the utility of using low-dose combinations of agents acting within the NMDA receptor complex to produce analgesic effects without producing motor dysfunction. In particular, we assessed the antinociceptive activity in the formalin test of combinations of competitive (APV) and non-competitive (MK-801) NMDA receptor antagonists with agonist and antagonists acting at allosteric-glycine and polyamine receptors. Both the competitive NMDA receptor antagonist APV and the non-competitive NMDA antagonist MK-801 produced dose-dependent analgesic effects in the late, but not the early, phase of the formalin test. The antinociceptive activity of APV was significantly enhanced by combination with a non-analgesic dose of the allosteric-glycine agonist glycine, and was reduced by combination with the allosteric-glycine antagonist 7-CKA which also reversed the glycine-induced enhancement of the antinociceptive effects of APV. The antinociceptive activity of MK-801 was significantly enhanced by combination with a non-analgesic dose of the polyamine agonist spermine, and reduced by combination with the polyamine receptor antagonist IFEN which also reversed the spermine-induced enhancement of the antinociceptive effects of MK-801. The enhancement of the antinociceptive activity of APV and MK-801 by glycine and spermine, respectively, was not accompanied by increases in motor dysfunction. Thus, by using specific combination of agents acting within the NMDA receptor complex, it was possible to produce effective antinociception in the formalin test at doses of NMDA receptor antagonists which did not produce motor dysfunction.

2-Amino-5-phosphonovalerate↗