It was hypothesized that a metabolite of morphine, morphine-3-glucuronide (M3G), contributes to the expression of symptoms seen during withdrawal from morphine. To test this hypothesis, the behaviors observed during precipitated withdrawal from morphine and sufentanil were compared. Sufentanil was chosen because, like morphine, it acts primarily at the mu opioid receptor, but has different metabolites. Differences in the abstinence syndromes produced by the two drugs may therefore be attributable to the actions of metabolites, rather than the primary opioid actions of morphine and sufentanil. Although there were some differences in the occurrence of symptoms, morphine and sufentanil withdrawal were very similar. Therefore, the evidence was inconclusive as to the contribution of metabolites during withdrawal. / Systemic administration of M3G alone and in combination with morphine produced no withdrawal-like behaviors. However, when these drugs were given centrally, withdrawal-like behaviors were observed in conjunction with seizures. The seizures were not attenuated by naloxone (but were alleviated by an anti-convulsant), indicating that they were not mediated by opioid receptors. The behaviors resembled those seen by previous investigators following high doses of morphine. The results suggest that M3G may play a role in the toxic effects of high doses of morphine.

No description available.

No description available.

Controversy exists concerning the role that dopamine plays in analgesia. In the present studies, dopamine agonists produced analgesia, and D-amphetamine potentiated morphine analgesia, while treatment with 6-hydroxydopamine or mixed or selective D1 and D2 dopamine receptor antagonists attenuated or abolished morphine and D-amphetamine-induced analgesia, in the formalin test. Furthermore, microinjection of morphine into the ventral tegmental area (VTA) and ventral striatum produced analgesia, while intra-VTA microinjection of naloxone methylbromide antagonized the analgesia produced by systemic morphine, in the formalin test. In contrast, similar manipulations of dopamine had little or no effect in the tail flick test. Thus, dopamine appears to play a facilitatory role in formalin test analgesia, and there appear to be fundamental differences between the formalin and tail flick tests and parallels between the role of dopamine in the formalin test and in clinical pain, the vocalization after-discharge test and reward.

The history of heroin use disorder intervention has been characterised by fads and fashions. Some of the treatments that have been used have been, at best ineffective, and at worst harmful, and occasionally even dangerous. It is a sad reflection upon the field that practices and procedures for the treatment of heroin use disorders can so easily be introduced and applied without (or even contrary to) evidence. In South Africa, the field of heroin use disorder intervention has been `in transition' since the outbreak of the heroin epidemic. Yet despite growing evidence of an association between heroin dependents use of supplementary intervention services (such as psychosocial and pharmacological/medical care) and intervention outcomes, and the fact that international emerging standards for substance use disorder intervention have called upon treatment intervention providers to enhance traditional substance use disorder services with services that address clients' psychological and social needs, heroin use disorder intervention programmes in South Africa generally fail to meet these research-based intervention standards. Much of what is currently delivered as intervention is based upon current best guesses of how to combine some science-based (for example, cognitive-behavioural therapy and pharmacotherapies) and self-help (12-step programmes) approaches into optimal intervention protocols. As progression is made in the twenty-first century, scientific information is now beginning to be used to guide the evolution and delivery of heroin use disorder care internationally. Regrettably, a scarcity of heroin use disorder intervention research is noted in South Africa. The present study delved into the insights of ten heroin use disorder specialists, and synthesised the findings with the results of a previous study undertaken by the author relating to forty long-term voluntarily abstinent heroin dependents. In terms of theory and practice, findings of the study suggest that the field is less in transition now than it was in 1995. It is an imperative that law-enforcement action be followed by an integrated programme of psychological, social and pharmacological outreach. These programmes will have to be expanded to address new demands and will need to include specialised skills training. Many interventions and procedures have begun to be integrated routinely into clinical practice. / Psychology / (D. Phil. (Psychology))

The history of heroin use disorder intervention has been characterised by fads and fashions. Some of the treatments that have been used have been, at best ineffective, and at worst harmful, and occasionally even dangerous. It is a sad reflection upon the field that practices and procedures for the treatment of heroin use disorders can so easily be introduced and applied without (or even contrary to) evidence. In South Africa, the field of heroin use disorder intervention has been `in transition' since the outbreak of the heroin epidemic. Yet despite growing evidence of an association between heroin dependents use of supplementary intervention services (such as psychosocial and pharmacological/medical care) and intervention outcomes, and the fact that international emerging standards for substance use disorder intervention have called upon treatment intervention providers to enhance traditional substance use disorder services with services that address clients' psychological and social needs, heroin use disorder intervention programmes in South Africa generally fail to meet these research-based intervention standards. Much of what is currently delivered as intervention is based upon current best guesses of how to combine some science-based (for example, cognitive-behavioural therapy and pharmacotherapies) and self-help (12-step programmes) approaches into optimal intervention protocols. As progression is made in the twenty-first century, scientific information is now beginning to be used to guide the evolution and delivery of heroin use disorder care internationally. Regrettably, a scarcity of heroin use disorder intervention research is noted in South Africa. The present study delved into the insights of ten heroin use disorder specialists, and synthesised the findings with the results of a previous study undertaken by the author relating to forty long-term voluntarily abstinent heroin dependents. In terms of theory and practice, findings of the study suggest that the field is less in transition now than it was in 1995. It is an imperative that law-enforcement action be followed by an integrated programme of psychological, social and pharmacological outreach. These programmes will have to be expanded to address new demands and will need to include specialised skills training. Many interventions and procedures have begun to be integrated routinely into clinical practice. / Psychology / (D. Phil. (Psychology))