Repeated peripheral administration of the micro-opioid agonist [D-Ala2,N-Me-Phe4,gly5-ol] enkephalin (DAMGO) produces acute tolerance and dependence on its peripheral antinociceptive effect against prostaglandin E2 (PGE2)-induced mechanical hyperalgesia. In this study we evaluated the roles of protein kinase C (PKC) and nitric oxide (NO) in the development of this tolerance and dependence. Repe...


 Injectable diacetylmorphine might provide more benefits and lower costs compared with oral methadone maintenance therapy in patients severe opioid use disorder.
 The Canadian Research Initiative Substance Misuse guideline recommends that both injectable hydromorphone should be considered as treatment options for individuals severe, treatment-refractory disorder ongoing illicit injec...

Recent data suggest that opioid receptors are involved in the development of nicotine physical dependence in mammals. Evidence in support of a similar involvement in an invertebrate (Planaria) is presented using the selective opioid receptor antagonist naloxone, and the more receptor subtype-selective antagonists CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2) (μ, MOR), naltrindole (δ, DOR), and...

INTRODUCTION Zinc chelators were shown to facilitate some opioid-withdrawal signs in animals. Zinc deficiency, which affects more than 15% the world's population, is also common among opioid consumers and opioid-treated animals exhibit misbalances of zinc distribution. AIM The present study focuses on how zinc ions interfere with opioid dependence/addiction and analgesia, trying to preliminar...

INTRODUCTION Opioid dependence is recorded as the most common drug of abuse in Malaysia. Currently, the preferred substitution therapy for most Government treatment centres is methadone used as substitution therapy for opioid dependence. There are, however patients who may benefit from being on the combined buprenorphine-naloxone formulation as substitution therapy instead. We discuss six cases...

Nicotine is the primary component of tobacco that maintains the smoking habit and develops addiction. The adaptive changes of nicotinic acetylcholine receptors produced by repeated exposure to nicotine play a crucial role in the establishment of dependence. However, other neurochemical systems also participate in the addictive effects of nicotine including glutamate, cannabinoids, GABA and opio...

Maintenance therapy with methadone or buprenorphine is an established and first-line treatment for opioid dependence. Clinical studies indicate that about a third of patients in opioid maintenance therapy show increased alcohol consumption and alcohol use disorders. Comorbid alcohol use disorders have been identified as a risk factor for clinical outcome and can cause poor physical and mental h...

combined use of an opioid with a psychostimulant is popular among drug abusers. such “polydrug use” may increase drug effects or attenuate adverse effects of either drug alone. we proposed that a combination of methamphetamine (meth) and morphine may change physical opioid withdrawal symptoms. adult male rats were chronically injected with cumulative subcutaneous (s.c.) doses of morphine, meth ...