As long-term opioids are increasingly used for control of chronic pain, how pain affects the rewarding effect of opioids and hence risk of prescription opioid misuse and abuse remains a healthcare concern and a challenging issue in current pain management. In this study, using a rat model of morphine self-administration, we investigated the molecular mechanisms underlying the impact of pain on ...

Opiates have been reported to induce T cell loss. We evaluated the role of vitamin D receptor (VDR) and the activation of the renin-angiotensin system (RAS) in morphine-induced T cell loss. Morphine-treated human T cells displayed downregulation of VDR and the activation of the RAS. On the other hand, a VDR agonist (EB1089) enhanced T cell VDR expression both under basal and morphine-stimulated...

Drug addiction is increasingly viewed as the expression of abnormal associative learning following repeated exposures to the drugs of abuse. Previous studies have demonstrated that the patterns of repetition such as frequency and spacing are important to many kinds of learning and memory retention. We hypothesized that drug repetition pattern might affect the reward-related learning although th...

The present study aimed to investigate the stability of morphine, morphine-3-β-glucuronide (M3G), morphine-6-β-glucuronide (M6G), 6-acetylmorphine (6-AM) from heroin metabolites, and codeine, codeine-6-glucuronide, nor-codeine, fentanyl, norfentanyl, paracetamol, caffeine its adulterants at room temperature for 24 hours in order understand effect instability postmortem redistribution (PMR). m...

The increasing prescription of opioids is fueling an epidemic of addiction and overdose deaths. Morphine is a highly addictive drug characterized by a high relapse rate - even after a long period of abstinence. Serotonin (5-HT) neurotransmission participates in the development of morphine dependence, as well as the expression of morphine withdrawal. In this study, we examined the effect of bloc...

Brown Mixture (BM), containing opium powder (10.0-10.5% morphine), opium tincture (0.9-1.1% morphine), or camphorated opium tincture (0.045-0.055% morphine), is a popular remedy, while heroin use is prohibited in Taiwan. Thus, for specimens that are tested positive for morphine, specimen donors' claims of BM use have to be adequately addressed. This study was designed to develop and validate a ...

Objective To compare the relative human abuse potential of intact and manipulated morphine abuse-deterrent, extended-release injection-molded tablets (morphine-ADER-IMT) with that of marketed morphine sulfate ER tablets. Methods This randomized, double-blind, triple-dummy, active- and placebo-controlled, 4-way crossover, single-center study included adult volunteers who were experienced, nond...

Background: There is growing evidence indicating that neuronal calcium channels play an important role in the mechanism of Morphine dependence. Objective: To investigate the acute and long-term effects of Verapamil in Morphine dependent mice. Methods: Mice were rendered dependent on Morphine by subcutaneous injection of Morphine over a period of 5 days. The effects of acute and chronic administ...

INTRODUCTION Consumption of codeine can lead to positive urine test for morphine in athletes. Morphine is classified as a prohibited doping drug while Codeine is not. Morphine/codeine ratio is used in forensic medicine to distinguish the consumption of codeine from abuse of morphine and other narcotics. CASE PRESENTATION We present an athlete with positive urine test for morphine with a histo...

Morphine is a potent opioid analgesic. However, the repeated use of morphine causes tolerance and hyperalgesia. Neuroinflammation has been reported to be involved in morphine tolerance and withdrawal-induced hyperalgesia. The complement system is a crucial effector mechanism of immune responses. The present study investigated the roles of complement factor C5a and C5a receptor (C5aR) in the dev...