The reports of analgesic effects of benzodiazepines are inconsistent. There is evidence of a hyperalgesic effect induced by activation of supraspinal GABAA receptors and an antinociceptive effect induced by activation of receptors located in the spinal cord (dorsal horns). The aim of the study was to discover whether the systemic administration of a benzodiazepine agent alprazolam increases the systemic analgesic efficacy of non-opioid analgesic ibuprofen. Experimental studies combining these agents have not yet been published. We used three experimental methods - writhing test (with acetic acid), tail-flick test and plantar test to assess analgesic action. The drugs were administered orally. Augmentation of the analgesic effect of ibuprofen by alprazolam was proved for the writhing test at a dose of 30 mg/kg of ibuprofen and alprazolam 1 mg/kg. The reaction time of the combination was significantly prolonged in comparison with ibuprofen alone. The results of the tail-flick test and plantar test were negative. The effect of ibuprofen was not enhanced by alprazolam in tests of acute thermal pain. Our results have demonstrated that the analgesic action of ibuprofen is only weakly enhanced by alprazolam., T. Doležal, M. Kršiak., and Obsahuje bibliografii
Benzodiazepines seem to be frequently abused in conjunction with opioids. Fluoxetine was reported to block morphine locomotor sensitization in rats. Sensitization has been implicated in some aspects of drug abuse. We have investigated the effect of alprazolam (0.25 mg/kg) and fluoxetine (5 mg/kg) on the development and expression of sensitization to the locomotor stimulant effect of morphine (10 mg/kg) in mice. Sensitization was produced by daily injections of morphine (10 mg/kg) for 10 days. There was a clear sensitization of locomotor activity produced by morphine in photocell activity cages but co-administration of alprazolam with morphine had no effect on the degree of sensitization. Alprazolam was also without effect on the expression of the sensitized response to morphine in mice sensitized with morphine alone. Fluoxetine partly reduced both the development and expression of morphine sensitization. In conclusion, the present experiments have not yielded evidence that alprazolam may influence the development or the expression of sensitization to morphine. However, they have corroborated and extended results indicating that fluoxetine can attenuate, to a certain level, the development and expression of morphine sensitization., M. Votava, M. Kršiak, V. Moravec., and Obsahuje bibliografii