Pharmacol Rep
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Comparative Study
Synergistic interaction of pregabalin with the synthetic cannabinoid WIN 55,212-2 mesylate in the hot-plate test in mice: an isobolographic analysis.
The aim of the study was to determine the type of interaction between pregabalin (a 3(rd)-generation antiepileptic drug) and WIN 55,212-2 mesylate (WIN - a highly potent non-selective cannabinoid CB1 and CB2 receptor agonist) administered in combination at a fixed ratio of 1:1, in the acute thermal pain model (hot-plate test) in mice. ⋯ Isobolographic analysis demonstrated that the combination of WIN with pregabalin at a fixed ratio of 1:1 exerted synergistic interaction in the mouse model of acute thermal pain. If the results from this study could be adapted to clinical settings, the combination of WIN with pregabalin might be beneficial for pain relief in humans.
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Immediate early gene (IEG) induction elicited by drugs of abuse may contribute to development of plastic changes in the brain responsible for drug-induced behavioral changes leading to addiction. The aim of the present study was to characterize the changes in IEG expression in the striatum and nucleus accumbens produced by an acute or chronic administration of morphine. ⋯ Our data indicate that morphine up-regulates many IEG in the mouse striatum at a strikingly delayed time-point and that these changes are genotype-dependent. They also suggest inter-strain differences in the development of striatal neuroadaptations to chronic morphine treatment.
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Sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, has recently been reported to influence the antidepressant activity of some antidepressant drugs. The present study was undertaken to investigate the involvement of the nitric oxide/cyclic guanosine 3',5'-monophosphate/PDE5 (NO/cGMP/PDE5) signaling pathway in the antidepressant activity of paroxetine and to assess the interaction between paroxetine and sildenafil, in the forced swim test in mice. ⋯ The results suggest that paroxetine may exert its antidepressant action by decreasing cGMP levels and sildenafil, as a drug which has the opposite effect on the processes mediated via the NO/cGMP/PDE5 signaling pathway, may decrease the efficacy of paroxetine. However, the co-administration of paroxetine with sildenafil resulted in a potent reduction (80%) of locomotor activity, which suggests that the reversal of antidepressant action of paroxetine may have been a result of locomotor deficits. Further studies are required to explain the mechanism underlying this phenomenon.
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Interleukin-1β (IL-1β), the major cytokine involved in activation of hypothalamic-pituitary-adrenal (HPA) axis modulates both central and peripheral components regulating HPA activity. The role of nitric oxide (NO) generated by neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in brain structures involved in HPA axis regulation has not been elucidated. The aim of the study was to assess the receptor selectivity of IL-1β stimulatory action on HPA axis and to determine the involvement of nNOS and iNOS in this stimulation. ⋯ The present study suggests that the IL-1β-induced transient stimulation of HPA axis activity is parallel in time and magnitude to the respective changes of nNOS in hypothalamus and prefrontal cortex, the brain structures involved in regulation of HPA axis activity.
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Multicenter Study Clinical Trial
Transdermal buprenorphine in the treatment of cancer and non-cancer pain - the results of multicenter studies in Poland.
This was a multicenter, non-interventional, post-marketing study that aimed to evaluate the analgesic activity, safety of use, safety profile and adverse drug reactions of transdermal buprenorphine (Transtec 35, 52.5 and 70 μg/h) during the treatment of moderate to severe chronic cancer and non-cancer pain. The study was performed in Poland by 339 doctors. The study involved 4,030 general practice outpatients (managed by primary care physicians), pain therapy center patients, specialist outpatient clinic patients as well as patients treated in inpatients units. ⋯ Patients were enrolled if their pain was not well-controlled after using non-opioid analgesics. Another objective of the study was to monitor adverse drug reactions of transdermal buprenorphine reported by patients or noted by the doctors during the study visits. This first such multicenter study in Poland has confirmed high efficacy and good tolerability of buprenorphine and, therefore, confirmed its usefulness in the treatment of moderate to severe cancer pain as well as in the treatment of severe pain in patients with non-cancer pain that cannot be effectively treated with non-opioid analgesics.