opium is one of the oldest herbal medicines currently used as an analgesic, sedative and antidiarrheal treatment. the effects of opium are principally mediated by the μ -,κ- and δ-opioid receptors. opioid substances consist of all natural and synthetic alkaloids that are derived from opium. most of their effects on gastrointestinal motility and secretion result from suppression of neural activi...

There is growing evidence that tonic activity of the opioid system may be important in the modulation of affective state. Naloxone produces a conditioned place aversion in rodents, an effect that is centrally mediated. Previous pharmacological data using antagonists with preferential actions at mu-, delta-, and kappa-opioid receptors indicate the importance of the mu-opioid receptor in mediatin...

Intraplantar formalin injection is widely used as an experimental model of tonic pain. We investigated the role of endogenous A-opioid receptor mechanisms in formalin-induced nocifensive behavior in mice. The flinching response induced by formalin (2%, 20 Al) was studied in mice with normal (wild type, n = 8) and absent (homozygous A-opioid receptor knockout, n = 8) A-opioid receptor levels. Th...

PURPOSE This study investigated the patterns of opioid co-prescription with benzodiazepine and other concomitant medications among opioid users. Opioid dose in each type of co-prescription was also examined. PATIENTS AND METHODS This cross-sectional study was conducted among opioid users receiving concomitant medications at an outpatient tertiary hospital setting in Malaysia. Opioid prescript...

Since 1952, when Gates determined the stereo structure of morphine, numerous groups have focused on discovering a nonnarcotic opioid drug. Although several natural, semisynthetic, and synthetic opioid ligands (alkaloids and peptides) have been developed in clinical studies, very few were nonnarcotic opioid drugs. One of the most important studies in the opioid field appeared in 1976, when Marti...