Morphine is endogenously synthesized in the central nervous system and endogenous dopamine is thought to be necessary for endogenous morphine formation. As Parkinson's disease results from the loss of dopamine and is associated with central pain, we considered how endogenous morphine is regulated in the untreated and l-DOPA-treated parkinsonian brain. However, as the cellular origin and overall...

Glial cells play a critical role in morphine tolerance, resulting from repeated administration of morphine. Both the development and the expression of tolerance are suppressed by the analgesic lamotrigine. This study investigated the relationship between the ability of lamotrigine to maintain the antinociceptive effect of morphine during tolerance development and glial cell activation in the sp...

In the adult male Sprague-Dawley rat, a species commonly used to study tolerance to the antinociceptive effects of morphine, approximately 10% of the morphine dose is metabolized to normorphine-3-glucuronide (NM3G). In contrast, NM3G is a relatively minor metabolite of morphine in human urine reportedly accounting for approximately 1% of the morphine dose. To date, the pharmacology of NM3G has ...

Intrathecal morphine is often used for postoperative analgesia after surgery. We performed a meta-analysis to obtain more detailed information on the frequency of side-effects in patients receiving intrathecal morphine in combination with spinal anaesthesia compared with placebo treated patients. We clustered the analysis to patients receiving placebo, less than morphine 0.3 mg (M < 0.3), or eq...

There is growing evidence indicating that neuronal calcium channels play an important role in the mechanism of morphine dependence. In this study, the effects of acute and chronic administration of nitrendipine on naloxone precipitated morphine withdrawal signs were investigated. Mice were rendered dependent to morphine by subcutaneous injection of morphine over a period of 5 days. In chronic s...

Because it generally is admitted that neuropathic pain is resistant to opioid analgesia, we investigated the effect of morphine on hyperalgesia in streptozocin-induced diabetes in rats. The antinociceptive effect of morphine (0.5-4 mg/kg i.v.) on mechanical (paw pressure test), thermal (tail immersion test) and chemical (formalin test) hyperalgesia was reduced. To clarify the mechanisms involve...

BACKGROUND Although intravenous morphine is commonly used for the treatment of chest pain in patients presenting with non-ST-segment elevation acute coronary syndromes (NSTE ACS), its safety has not been evaluated. The CRUSADE Initiative is a nonrandomized, retrospective, observational registry enrolling patients with NSTE ACS to evaluate acute medications and interventions, inhospital outcomes...

Morphine has been found in cow and human milk at concentrations of 200 to 500 nanograms per liter. Multistep purification yields a material that has immunological, biological, pharmacological, and chemical properties identical to those of morphine. Similar morphine-like material, which has been tentatively identified in some common plant sources, may be a ubiquitous dietary constituent and a po...

Morphine and other opioids is the mainstay of cancer pain management. However, considerable fears surrounding their use present barriers to pain control. The aim of this study was to assess the rational use and effectiveness of morphine for management of pain in the palliative care of cancer patients at Ocean Road Cancer Institute (ORCI) in Tanzania. A total of 100 cancer patients who were rece...

High doses of insurmountable antagonists or frequent administration of high doses of agonists are required to alter the potency of opioid agonists to produce discriminative stimuli. In the present study, insurmountable antagonism and repeated agonist treatment were combined to remove or disable a large enough proportion of mu-opioid receptors to alter the potency or maximal effect for four agon...