nalorphine and Pain

Topics: Analgesics; Animals; Behavior, Animal; Benzomorphans; Cyclazocine; Discrimination Learning; Dogs; Dopamine; Drug Tolerance; Electroencephalography; Humans; Macaca mulatta; Mice; Morphine; Morphine Dependence; Motor Activity; Nalorphine; Pain; Rabbits; Rats; Receptors, Dopamine; Receptors, Opioid; Receptors, Opioid, kappa; Seizures; Temperature

Topics: Age Factors; Analgesics; Animals; Aspirin; Behavior, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Electrodes, Implanted; Electroshock; Hot Temperature; Methods; Mice; Nalorphine; Narcotic Antagonists; Narcotics; Pain; Pressure; Rats; Reaction Time; Reflex; Sex Factors; Spasm; Species Specificity; Tail; Time Factors; Vocalization, Animal

Topics: Analgesics; Blood Circulation; Fentanyl; Humans; Intestines; Levallorphan; Meperidine; Methadone; Methotrimeprazine; Morphinans; Morphine; Nalorphine; Narcotic Antagonists; Nausea; Pain; Pentazocine; Psychopharmacology; Respiration; Substance-Related Disorders; Urinary Tract; Vomiting

Topics: Analgesics; Aspirin; Caffeine; Clinical Trials as Topic; Codeine; Dextropropoxyphene; Female; Headache; Humans; Indoles; Isoquinolines; Meperidine; Morphine; Nalorphine; Narcotics; Pain; Periodontal Diseases; Phenacetin; Placebos; Postoperative Care; Pregnancy; Puerperal Disorders; Substance Withdrawal Syndrome; Substance-Related Disorders; Tranquilizing Agents

This report-the second of a series on codeine and its alternates for pain and cough relief-contains a detailed evaluation of experimental and clinical data on newer substances having analgesic properties comparable to and in approximately the same range as those of codeine. The data are discussed under the headings: analgesic effects in animals; clinical usefulness; side-effects with particular reference to dependence and abuse liability.

Topics: Amides; Analgesics; Animals; Antitussive Agents; Azepines; Carisoprodol; Cats; Chickens; Codeine; Cough; Cyclazocine; Dextropropoxyphene; Diphenylacetic Acids; Dogs; Ducks; Guinea Pigs; Humans; Indenes; Indoles; Isoquinolines; Mice; Morphinans; Nalorphine; Narcotic Antagonists; Pain; Pentazocine; Phenethylamines; Pyrrolidines; Rats; Substance-Related Disorders; Thalidomide

Topics: Anesthesia; Diagnosis; Fetus; Humans; Infant, Newborn; Nalorphine; Narcotic Antagonists; Pain; Pharmacology; Respiration; Substance-Related Disorders; Toxicology

Topics: Analgesics; Analgesics, Non-Narcotic; Antipyretics; Biphenyl Compounds; Chemistry, Pharmaceutical; Heroin; Morphine; Nalorphine; Pain; Piperidines

Topics: Adult; Aged; Amines; Amino Alcohols; Analgesics; Benzyl Compounds; Blood Pressure; Body Temperature; Clinical Trials as Topic; Female; Humans; Male; Middle Aged; Nalorphine; Pain; Pulse; Pyrroles; Respiration; Substance Withdrawal Syndrome

Topics: Analgesics; Animals; Clinical Trials as Topic; Injections, Intramuscular; Morphinans; Nalorphine; Neoplasms; Pain; Palliative Care; Respiration; Terminal Care

Topics: Analgesics; Aspirin; Caffeine; Clinical Trials as Topic; Codeine; Dextropropoxyphene; Female; Headache; Humans; Indoles; Isoquinolines; Meperidine; Morphine; Nalorphine; Narcotics; Pain; Periodontal Diseases; Phenacetin; Placebos; Postoperative Care; Pregnancy; Puerperal Disorders; Substance Withdrawal Syndrome; Substance-Related Disorders; Tranquilizing Agents

Topics: Female; Humans; Injections, Intramuscular; Injections, Intravenous; Levallorphan; Meperidine; Nalorphine; Pain; Pentazocine; Placebos; Preanesthetic Medication

On the basis of a case study, the complex problems of the final stages of a COPD will be demonstrated and discussed. Dyspnea and anxiousness are the primary symptoms. If they can be adequately brought under control by opiates and benzodiazepines, a palliative sedation is then not necessary. The communicative and ethical demands on the team responsible are high. It is important to be aware of the specific needs of the patient and of his/her family members, and to competently accompany the patient throughout the decision-making process--such as the decision to end respiratory therapy, for example. Clarifying the situation with the patient and finding out his/her wishes, accompanied by the corresponding documentation, is advisable.

Topics: Aged; Anxiety; Conscious Sedation; Continuous Positive Airway Pressure; Drug Combinations; Ethics, Medical; Humans; Male; Medical Futility; Morphine; Morphine Derivatives; Nalorphine; Pain; Palliative Care; Pulmonary Disease, Chronic Obstructive; Terminal Care; Treatment Refusal

Topics: Adult; Chromatography, Gas; Female; Humans; Hydrolysis; Kidney; Male; Middle Aged; Morphine; Nalorphine; Neoplasms; Pain

We report a nociceptive test involving peripheral irritation which produces behavior similar to that elicited by intrathecally injected substance P. Intradermal hypertonic saline injected to the lower abdominal area produced quantifiable behavior in mice. The behavior consisted of licking, biting and scratching directed to the location of i.d. injection, and was dose-dependent with respect to the concentration and volume of saline. Intrathecally administered (D-Pro2, D-Trp7,9)-SP, a substance P antagonist, dose-dependently blocked the behaviors induced by intrathecally administered substance P as well as those induced by intradermally injected hypertonic saline, indicating a possibly common final pathway at the spinal cord level for the manifestation of both behaviors. Hypertonic saline-induced behavior was blocked completely by morphine and a partial opiate agonist (pentazocine) in a dose-dependent manner, but was not blocked by another partial opiate agonist (nalorphine). The behavior was not blocked by non-steroidal anti-inflammatory agents. This nociceptive test, in conjunction with the substance P-induced behavior test, may allow discrimination between agents acting pre- or post-synaptically in the spinal cord. Baclofen, a GABAB agonist thought to act presynaptically, changed substance P-induced behavior and hypertonic saline-induced behavior in opposite directions.

Topics: Animals; Anti-Inflammatory Agents; Baclofen; Behavior, Animal; Dose-Response Relationship, Drug; Injections, Intradermal; Injections, Spinal; Male; Mice; Morphine; Nalorphine; Pain; Pentazocine; Saline Solution, Hypertonic; Sodium Chloride; Spinal Cord; Substance P

Exposure of mice to cold-restraint stress markedly decreased the number of abdominal constrictions induced by IP acetic acid. Naloxone pretreatment significantly attenuated the antinociceptive effect of cold-restraint stress, suggesting a partial mediation by opioid mechanisms. Pretreatment with the quaternary opioid antagonist methylnalorphinium did not reverse analgesia in stressed mice. Also, nociception in both stressed and non-stressed mice was not modified by pretreatment with the selective alpha 2-adrenoceptor blocker yohimbine. The results suggest that cold-restraint stress promotes analgesia in mice which is mediated in part by opioid but not alpha 2-adrenoceptor mechanisms. Furthermore, the results do not substantiate a peripheral analgesic role for circulating opioids in this model of stress.

Topics: Analgesia; Animals; Cold Temperature; Endorphins; Male; Mice; Nalorphine; Naloxone; Nervous System; Pain; Restraint, Physical; Stress, Physiological; Synaptic Transmission; Yohimbine

Three antagonists at the mu opiate receptor site: naloxone, naltrexone and diprenorphine, and one agonist-antagonist compound nalorphine, at doses usually not analgesic elicited analgesia in rats when administered after non-naloxone-reversible shock-induced analgesia had disappeared. The chi receptor antagonist, MR 2266, and the delta antagonist, ICI 154129, were all ineffective. This effect was no longer present when non-naloxone-reversible shock-induced analgesia was inhibited by the administration of the chi receptor antagonist, MR 2266. These results suggest that the mu opiate receptor may change its conformation under particular conditions such as continuous inescapable shock.

Topics: Analgesics; Animals; Diprenorphine; Electroshock; Male; Nalorphine; Naloxone; Naltrexone; Pain; Rats; Rats, Inbred Strains; Receptors, Opioid; Receptors, Opioid, mu; Stress, Physiological

Nalorphine, levallorphan and their quaternary analogs, N-(eq)allyl derivatives of the two diastereoisomers at the nitrogen atom (N-methyl nalorphine and N-methyl levallorphan) were tested for their peripheral selectivity. We compared their relative ability to prevent morphine-induced (5 mg/kg i.v.) antinociception (central antagonism) and constipation (peripheral antagonism) in the same rats. Nalorphine and levallorphan reduced morphine-induced antinociception to half maximal response at doses of 5.1 and 0.89 mg/kg s.c. and restored the intestinal transit to 50% of controls (AD50) respectively at doses of 0.25 and 0.12 mg/kg. N-methyl nalorphine up to 24 and N-methyl levallorphan up to 30 mg/kg given s.c. 10 min before morphine did not antagonize narcotic-induced antinociception, fully preventing constipation (AD50 0.65 and 0.32 mg/kg respectively), but when injected 50 min before morphine they partially lost their antagonist potency (AD50 2.3 and 2.6 mg/kg respectively) and peripheral selectivity. N-methyl nalorphine and N-methyl levallorphan thus seem more peripherally selective than their tertiary analogs and more potent than quaternary narcotic antagonists tested to date.

Topics: Analgesia; Animals; Gastrointestinal Motility; Levallorphan; Male; Morphine; Nalorphine; Narcotic Antagonists; Pain; Rats; Rats, Inbred Strains; Structure-Activity Relationship

The profile of action of beta-funaltrexamine (beta-FNA), the fumaramate methyl ester derivative of naltrexone, on antinociceptive tests in vivo was investigated. Beta-FNA demonstrated antinociceptive actions that were of short duration and that appeared to be mediated by kappa receptor interaction. In contrast, the antagonist actions of beta-FNA were of remarkably long duration and were selective toward nu agonist interactions. This profile of action is consistent with the profile of action of beta-FNA in vitro. The selective long-lasting antagonism of mu-mediated effects by beta-FNA may be of great value in the elucidation of multiple opioid receptor function.

Topics: Acetates; Acetic Acid; Analgesics, Opioid; Animals; Drug Interactions; Female; Male; Mice; Morphine; Nalorphine; Naloxone; Naltrexone; Narcotics; Pain; Reaction Time

Single doses of naloxone (0.025 to 0.5 mg/kg) or of one of four quaternary narcotic antagonists (i.e. nalorphine allobromide, nalorphine methobromide, naloxone methobromide or naltrexone methobromide, 1 to 60 mg/kg) were given s.c. to rats before morphine, 5 mg/kg i.v. In the absence of antagonists morphine reduced G.I. transit of a charcoal meal to about 15% of drug-free controls and consistently delayed nociceptive reactions (55 degrees C hot plate) in all animals. Doses of antagonists slightly reducing morphine antinociception (centrally effective = A) and restoring G.I. transit to about 50% of drug-free rats (peripherally effective = B) were estimated. The A:B ratio, indicating peripheral selectivity, was at least 8 for any of the quaternary antagonists given 10 min before morphine, but prolonging this interval may have resulted in a lower figure (i.e. less peripheral selectivity) because of reduced A and increased B. This was definitely so for naltrexone methobromide (A:B, greater than 60 at 10 min, about 1 at 80 min) and was not apparent for nalorphrine methobromide according to available data, which for nalorphrine allobromide and to a lesser extent for naloxone methobromide showed only an increase in B at intervals longer than 10 min. Both morphine-induced antinociception and inhibition of G.I. transit were reduced by naloxone at the lower doses tested and were fully prevented at the higher. These findings indicated that, unlike naloxone, the investigated quaternary narcotic antagonists are interesting prototype drugs for selective blockade of opiate receptors outside the CNS, although certain critical aspects, possibly biological N-dealkylation to the corresponding tertiary antagonists, condition peripheral selectivity.

Topics: Analgesia; Animals; Dose-Response Relationship, Drug; Gastrointestinal Motility; Male; Morphine; Nalorphine; Naloxone; Naltrexone; Pain; Rats; Structure-Activity Relationship

Electrical stimulation of the rabbit sciatic nerve resulted in the development of shock. Injection of physiological saline (1 ml, i. v.) did not change the progressive fall of the blood pressure or depression of palpitation and respiration. The animals died 135--191 min after discontinuance of the stimulation. Injection of nalorphine (0.4 mg/kg, i. v.) or naloxone (0.1 mg/kg i. v.) greatly improved the animals' condition. The blood pressure, palpitation and respiration returned to normal in 90--120 min after the injections. No lethal cases were recorded in this group of animals. It was shown in a supplementary group of animals that naloxone did not change the reserpine-produced hypotension.

Topics: Animals; Drug Evaluation, Preclinical; Electroshock; Nalorphine; Naloxone; Pain; Rabbits; Shock; Time Factors

Topics: Analgesics; Animals; Aspirin; Codeine; Dextropropoxyphene; Erythromycin; Indomethacin; Male; Mice; Morphine; Nalorphine; Naloxone; Pain; Phenylbutazone

A series of 5-aryl-2-azabicyclo[3.2.1]octanes II has been synthesized and evaluated for analgetic agonist-antagonist activity. These compounds can be regarded as five-membered, conformationally more rigid analogues of the potent agonist-antagonist (-)-5-(3-hydroxyphenyl)-2-methylmorphan (I). Several of these compounds have demonstrated marked analgesic potency comparable to morphine in the mouse writhing assay. Structure-activity correlations, generated by varying N-substitution and O-acetylation of the phenolic function, seem to indicate that optimum activity is associated with an arylethyl side chain attached to the basic nitrogen. Among the most interesting compounds in this series are the phenethyl analogue 31 and its O-acetate 39; the former shows the profile of a well-balanced analgetic-antagonist virtually devoid of physical dependence liability as demonstrated in the rat infusion test.

Topics: Analgesics; Animals; Aza Compounds; Bridged Bicyclo Compounds; Bridged-Ring Compounds; Mice; Molecular Conformation; Pain; Quinones; Reaction Time; Structure-Activity Relationship

Acute experiments were conducted on unanesthetized curare-treated cats and rats. Analgetic doses of morphine and azidomorphine proved to depress the spontaneous and bradykinin-induced neuronal activity in the sensory-motor zone of the cerebral cortex. The inhibiting effect of the drugs was eliminated by nalorphine. It is supposed that the depressive action of morphine and azidomorphine may be connected with their direct influence on the cerebral cortex.

Topics: Animals; Bradykinin; Cats; Drug Interactions; Morphine; Morphine Derivatives; Motor Cortex; Nalorphine; Pain; Rats; Somatosensory Cortex

The effects of morphine (2 mg/kg i.v.) upon the transmission of nociceptive messages at the spinal level have investigated in decerebrate cats by studying its effects on the activities of lamina V dorsal horn interneurons. In contrast to previous results obtained on the spinal cat, morphine had little or no effects on lamina V type cells in the decerebrate preparation. The mean values for spontaneous activity and responses to natural noxious stimulation were practically identical before and after morphine administration. Moreover, no significant depressive effect was found on responses induced by supramaximal transcutaneous stimulation. However, for this type of activity a depressive effect was revealed, if only the late component of units which presented bimodal responses were considered. We were unable to demonstrate after morphine administration an increase of the descending inhibitory effects induced on lamina V cells by stimulation of the central inferior nucleus of the raphe. Additional experiments using reversible spinalization (by cooling the cord at the thoracic level) suggest that the lack of effect of morphine on decerebrate animals could be explained by the fact that in this preparation, descending inhibitory influences are strongly exacerbated and thus may mask the depressive effects of this drug. These results indicate that the direct electrophysiological evidence of an increase of the descending control systems after morphine administration must be performed in the intact preparation in order to avoid the effects ot their exacerbation in the decerebrate state.

Topics: Action Potentials; Animals; Cats; Decerebrate State; Evoked Potentials; Interneurons; Morphine; Nalorphine; Naloxone; Neural Inhibition; Pain; Spinal Cord; Synaptic Transmission

The effects of morphine upon the transmission of nociceptive messages at the spinal level have been investigated in spinal cats by studying its effects on the activities of lamina V dorsal horn interneurons. Morphine (2 mg/kg i.v.) induced a direct depressive action at the spinal level, since it strongly reduced both spontaneous and evoked activities of lamina V cells. The spontaneous firing rate and the responses elicited by natural nociceptive stimulation were decreased by 50%. The responses of these units evoked by supramaximal electrical stimulation were reduced to 67% of their initial value; in this case, the depressive effect was much more prominent on the late component of the long duration responses. The observed depressive effects are specific since they are immediately reversed by administration of opiate antagonists (nalorphine or naloxone).

Topics: Animals; Cats; Depression, Chemical; Evoked Potentials; Female; Interneurons; Male; Morphine; Nalorphine; Naloxone; Pain; Spinal Cord; Synaptic Transmission

Topics: Analgesics, Opioid; Animals; Cyclazocine; Dogs; Dose-Response Relationship, Drug; Drug Evaluation; Levallorphan; Movement; Nalorphine; Narcotic Antagonists; Opium; Pain; Pentazocine; Rats; Time Factors

Topics: Animals; Cats; Decerebrate State; Electric Stimulation; Electrodes, Implanted; Evoked Potentials; Microelectrodes; Morphine; Nalorphine; Naloxone; Pain; Physical Stimulation; Spinal Cord; Synaptic Transmission

Topics: Blood Gas Analysis; Drug Combinations; Female; Fetus; Humans; Hydrogen-Ion Concentration; Infant, Newborn; Injections, Intramuscular; Labor, Obstetric; Male; Morphinans; Morphine Derivatives; Nalorphine; Nicotinic Acids; Pain; Pregnancy; Respiration

Topics: Acetylcholine; Acetylcholinesterase; Animals; Brain; Brain Chemistry; Differential Threshold; Dose-Response Relationship, Drug; Female; Male; Morphine; Nalorphine; Naloxone; Oxotremorine; Pain; Rana esculenta; Reaction Time; Seasons; Spinal Cord

Topics: Acetylcholine; Animals; Anura; Brain; Brain Chemistry; Morphine; Nalorphine; Naloxone; Pain; Rana esculenta

Topics: Analgesics; Animals; Codeine; Dogs; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Formaldehyde; Hindlimb; Meperidine; Motor Activity; Nalorphine; Narcotic Antagonists; Pain; Pentazocine; Salivation; Time Factors

Tetrazolo-(5,4-a)-6-METHyl-uracil (compound VMI-502) and tetrazolo (5,4-a)-6-propyl-uracil (compound VMI-510) posses a marked sedative-hypnotic and analgesic action and a slightly expressed central skeletal muscles relaxant and anticonvulsant action. The analgesic (antinociceptive) action has been demonstrated by meens of 5 algesimetric methods. The compounds depress the pain reactions in case of stimulation of the superficial as well as of the deep nociceptors, too. Its analgesic action is about 3 times more intense then the action of codeine, about 20 times more intense then the action of amidopyrin and maetamizole, and about 2 times slighter then the action of morphine. The obtained results give the possibility of excluding the so called "false positive reaction". The studied compounds potentiate the analgesic action of the morphine and amidopyrine, applied in subanalgesic dose. It is assumed that by the mechanisme of his analgesic action the compounds VMI-502 and VMI-510 probably approach the non-narcotic analgesics.

Topics: Aminopyrine; Analgesics; Animals; Azoles; Drug Synergism; Mice; Morphine; Nalorphine; Pain; Tetrazoles; Uracil

Topics: Analgesics; Dextropropoxyphene; Drug Antagonism; Drug Combinations; Drug Prescriptions; Drug Tolerance; Humans; Isonipecotic Acids; Methadone; Nalorphine; Narcotics; Neoplasms; Pain; Palliative Care; Substance-Related Disorders; Terminal Care

Topics: Acetates; Aminopyrine; Analgesics; Animals; Aspirin; Bradykinin; Carotid Arteries; Chlorpromazine; Codeine; Indomethacin; Injections, Intra-Arterial; Levallorphan; Male; Methods; Methotrimeprazine; Mice; Morphine; Nalorphine; Narcotic Antagonists; Pain; Pentazocine

Topics: Analgesics; Animals; Aspirin; Codeine; Dextropropoxyphene; Dogs; Female; Fumarates; Inflammation; Male; Mice; Nalorphine; Pain; Propionates; Pyrrolidines; Rats

Topics: Adult; Aged; Anxiety; Butyrophenones; Female; Fentanyl; Humans; Injections, Intravenous; Male; Middle Aged; Myocardial Infarction; Nalorphine; Neuroleptanalgesia; Pain; Tranquilizing Agents

Topics: Humans; Morphine; Nalorphine; Pain

Topics: Analysis of Variance; Animals; Depression, Chemical; Male; Mice; Morphine; Muscles; Nalorphine; Pain; Quinones; Spasm; Time Factors

Topics: Animals; Drug Synergism; Ergonovine; Female; Male; Methyldopa; Morphine; Nalorphine; Pain; Proadifen; Rats

Topics: Adult; Analgesia; Animals; Blood Pressure; Chemical Phenomena; Chemistry; Chemistry, Organic; Cortisone; Diuresis; Drug Tolerance; Female; Gastrointestinal Motility; Humans; Hydromorphone; Male; Middle Aged; Morphine; Nalorphine; Organic Chemistry Phenomena; Pain; Rats; Respiration

Topics: Analgesia; Codeine; Injections; Injections, Intraperitoneal; Injections, Subcutaneous; Morphine; Nalorphine; Pain; Pain Management; Pharmacology; Rats; Research; Toxicology

Topics: Analgesia; Anesthesia; Anesthesia, Conduction; Anesthesia, General; Anesthesia, Inhalation; Anesthesia, Obstetrical; Chloral Hydrate; Chlorpromazine; Female; Humans; Hypnotics and Sedatives; Infant; Infant, Newborn; Meperidine; Midwifery; Morphine; Nalorphine; Nitrous Oxide; Pain; Pentobarbital; Pregnancy; Secobarbital; Toxicology; Trichloroethylene

Topics: Aminopyrine; Analgesics; Analgesics, Non-Narcotic; Anilides; Antipyretics; Aspirin; Bradykinin; Dogs; Injections, Intra-Arterial; Levorphanol; Meperidine; Morphine; Nalorphine; Narcotics; Oxyphenbutazone; Pain; Pharmacology; Phenylbutazone; Research; Salicylic Acid; Toxicology; Visceral Pain

Topics: Analgesia; Animals; Brain; Calcium; Cell Membrane Permeability; Cerebral Cortex; Edetic Acid; Electric Stimulation; Mice; Morphine; Nalorphine; Pain; Pharmacology; Research

Topics: Analgesics; Analgesics, Non-Narcotic; Antipyretics; Apnea; Chemical Phenomena; Chemistry; Methadone; Mice; Morphine; Nalorphine; Pain; Pharmacology; Proadifen; Research; Seizures; Toxicology

Topics: Analgesics; Analgesics, Non-Narcotic; Antipyretics; Brain; Brain Stem; Cats; Dental Pulp; Electric Stimulation; Electrophysiology; Morphine; Nalorphine; Neural Conduction; Pain; Pentazocine; Pentobarbital; Pharmacology; Research

Topics: Acridines; Analgesia; Analgesics; Indoles; Mice; Morphine; Nalorphine; Narcotic Antagonists; Pain; Pain Management; Reaction Time; Research; Toxicology; Tremor; Tryptophan

Topics: Analgesia; Anesthesia; Anesthesia and Analgesia; Humans; Morphine; Nalorphine; Pain; Pain Management

In the rat, the ratio of the analgesic to the respiratory depressant potency was the same for morphine, codeine, diamorphine, methadone, dipipanone, piperidylisomethadone, phenadoxone, dextromoramide, and propoxyphene. The relative respiratory depressant activity of pethidine tended to be less, but the difference was not significant. The ratio of the analgesic dose to the dose preventing transport of a charcoal meal in the rat was about the same for morphine, codeine, pethidine, methadone, phenadoxone, dimethylthiambutene, and propoxyphene; the relative activities of these compounds in inhibiting the peristaltic reflex of the isolated guinea-pig ileum were also similar. However, because of differences in the slopes of regression lines in the charcoal meal test, some compounds (for example, morphine) had a greater effect on gastrointestinal propulsion than others (for example, pethidine) when given at moderate analgesic dose levels.In studies of the effects of intracisternal morphine in the rat, effects on the spinal reflex of the tail were to some extent dissociated from effects on the threshold for a squeak response. Further, the delaying of transport of a charcoal meal paralleled depression of respiratory rate, and this is evidence for the participation of a central as well as a peripheral action in the effect of morphine on the gastrointestinal tract. The delay in propulsion was reduced by nalorphine and increased by atropine and two general anaesthetic substances, but was unaffected by a number of other pharmacological agents.

Topics: Analgesics; Analgesics, Non-Narcotic; Analgesics, Opioid; Animals; Antipyretics; Cell Respiration; Codeine; Dextromoramide; Gastrointestinal Tract; Guinea Pigs; Meperidine; Methadone; Morphine; Nalorphine; Pain; Pain Threshold; Rats; Respiration; Respiratory Rate