Morphine and delta9-tetrahydrocannabinol (THC) produce antinociception via mu opioid and cannabinoid CB1 receptors, respectively, located in central nervous system (CNS) regions including periaqueductal gray and spinal cord. Chronic treatment with morphine or THC produces antinociceptive tolerance and cellular adaptations that include receptor desensitization. Previous studies have shown that a...

PURPOSE To define the dose ratio between morphine and methadone in relation to the previous morphine dose and the number of days needed to achieve the same level of analgesia in a group of patients with advanced cancer with pain who switched from morphine to oral methadone. PATIENTS AND METHODS A cross-sectional prospective study of 38 consecutive cancer patients who switched from morphine to...

the pain is the most common complaint in various diseases. postoperative pain is common complication and spatially in elderly patient because of exacerbation of heard and vessel was impotents. the aim of this study was evaluation of the effect of low-dose iv dexamethasone on postoperative pain in patients with lumbar discectomy.   in a clinical trial that studied in neurosurgery wards of shohad...

we have previously evaluated the effect of nimodipine, l-type calcium channel blocker, on memory loss during spontaneous morphine withdrawal. in the present study the effect of nimodipine on memory loss in naloxone-induced morphine withdrawal mice was investigated. mice were made dependent by increasing doses of morphine for three days. object recognition task that was used for evaluation of me...

previous studies have shown that the extract of papaver rhoeas reduces morphine dependence, locomotor activity and reward. in present study, the effects of hydro-alcohol extract of papaver rhoeas on the tolerance to analgesic effects of morphine in mice have been investigated using tail flick method. subcutaneous (s.c.) administration of morphine (1, 2, 5 and 10 mg/kg) induced analgesia. howeve...

Objective: It has been shown that berberine, a major component of Berberis vulgaris extract, modulates the activity of several neurotransmitter systems including dopamine (Da) and N-methyl-D-aspartate (NMDA) contributing to rewarding and reinforcing effects of morphine. Drug craving and relapsing even after a long time of abstinence therapy are the most important problems of addiction. In the p...

introduction: activation of n-methyl-d-aspartate (nmda) glutamate receptors in the nucleus accumbens is a component of drug-induced reward mechanism. in addition, nmda receptors play a major role in brain reward system and activation of these receptors can change firing pattern of dopamine neurons. blockade of glutamatergic neurotransmission reduces the expression of conditioned place preferenc...