Clinical studies report a low incidence of intestinal side effects with transdermally administered fentanyl (TTS-fentanyl) in comparison with oral morphine. To support these clinical data, analgesic and intestinal effects of both opioids were compared in rats. After subcutaneous injection, analgesia in the tail withdrawal reaction test was obtained at a peak effect dose of 0.032 mg/kg with fent...

BACKGROUND The spinal administration of some N-methyl-d-aspartate receptor antagonists results in antinociception and potentiates the effects of opioids and alpha2-adrenoceptor agonists, but ketamine and its enantiomers have not been examined. The present study investigated the interactions of racemic ketamine, R(-)-ketamine and S(+)-ketamine with morphine and with dexmedetomidine. METHODS In...

Once-daily extended-release (ER) morphine sulfate (Avinza, Ligand) proved superior to twice-a-day, controlled-release oxycodone HCl (OxyContin, Purdue Pharma) for chronic, moderate-to-severe low back pain in patients naive to sustained-release opioids. Researchers enrolled 392 individuals into an open-label, randomized, parallel-group, multicenter study. The patients underwent titration of thei...

introduction: nitric oxide (no) is a neuronal messenger molecule in the central nervous system, which is generated from l-arginine by nitric oxide synthase (nos) and involves in many important opioid-induced effects. our previous studies revealed that cuminum cyminum interestingly reduces morphine sensitization, tolerance and dependency in male mice. therefore, in the present study, the effect ...

The major objective of this paper is to characterize the mechanism by which morphine modulates lymphocyte function and if these effects are mediated through the mu-opioid receptor. We evaluated the in vitro effects of morphine on lymphocytes that were freshly isolated from lymph nodes from wild type (WT) and mu-opioid receptor knock-out (MORKO) mice. Results show that morphine inhibits Con A-in...

The present studies characterized the receptor mechanisms of morphine-induced states of memory. Morphine (5 mg/kg) produced a state in which rats could learn and retrieve an operant response; retrieval was impaired, however, when the rats were tested in the normal state. Conversely, rats that were trained in the normal state failed to retrieve the response in the morphine state. In either case ...

Our previous studies indicate that oxycodone is a putative kappa-opioid agonist, whereas morphine is a well documented micro-opioid agonist. Because there is limited information regarding the development of tolerance to oxycodone, this study was designed to 1) document the development of tolerance to the antinociceptive effects of chronically infused i.v. oxycodone relative to that for i. v. mo...

Certain actions of doxapram, administered alone and in combination with morphine, have been examined in the rabbit and the mouse. Single doses of doxapram were capable of stimulating respiration in both species. There was an increase in tidal volume in the rabbit and an increase in respiratory rate in the mouse. In both species the duration of action of single doses of doxapram was less than 15...

carum copticum from apiaceae family has several biological effects including analgesic, anti-inflammatory, anxiolytic and antispasmodic activities. this study was designed to evaluate its effect on suppression of naloxone-induced morphine withdrawal signs. hydroalcoholic and polyphenolic extracts were prepared according to the standard methods. male mice (25-30 g) were made dependent by subcuta...