Psychopharmacology
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Randomized Controlled Trial Multicenter Study Clinical Trial
Double blind study of tiapride versus haloperidol and placebo in agitation and aggressiveness in elderly patients with cognitive impairment.
The aim of the present study was to compare the efficacy and safety of tiapride versus haloperidol and placebo in the treatment of agitation and aggressiveness in elderly patients with mild or moderate mental impairment. ⋯ Tiapride is not different from haloperidol in the treatment of agitation and aggressiveness in elderly patients and better tolerated, in particular with significantly fewer extrapyramidal symptoms.
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Pairings of a sweet taste and injection of morphine result in a learned avoidance of that taste and learned analgesic tolerance. This avoidance is mediated by the drug's peripheral effect, while learned tolerance involves activation of N-methyl-D-aspartate (NMDA) receptors. Exposure to a sweet taste also reduces morphine analgesia. We studied whether this taste-mediated reduction was reversed by an NMDA or peripheral opioid receptor antagonist. ⋯ These results document evidence for an antagonism of morphine analgesia by actions of the drug at peripheral opioid receptors and excitatory amino-acid activity at NMDA receptors. They are discussed with reference to the aversive motivational effects of peripheral opioid receptors and pain facilitatory circuits.
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Comparative Study Clinical Trial Controlled Clinical Trial
Effects of buprenorphine versus buprenorphine/naloxone tablets in non-dependent opioid abusers.
Buprenorphine is an opioid agonist-antagonist under development in the United States as a sublingual medication for treatment of opioid dependence. Buprenorphine may be abused; therefore, tablets combining buprenorphine with naloxone have been developed with the intent of reducing the abuse risk in people physically dependent upon opioids. The characteristics and abuse potential of buprenorphine and buprenorphine/naloxone tablets in non-dependent opioid abusers have not been determined. Non-parenteral abuse of opioids such as buprenorphine may be more likely in people who have less severe substance abuse disorders (e.g., are not physically dependent upon opioids). ⋯ These results suggest that sublingual buprenorphine and buprenorphine/naloxone may both be abused by opioid users who are not physically dependent upon opioids.
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Methoclocinnamox (MC-CAM) possesses initial partial micro-opioid agonist activity with subsequent long-lasting micro-antagonist effects. This profile of activity is similar to that of buprenorphine, a compound with proposed use in the treatment of opioid abuse, suggesting a possible therapeutic use for MC-CAM as well. ⋯ These data suggest that MC-CAM has a longer duration of antagonist effects than buprenorphine and it may therefore have an advantage in the treatment of opioid abuse.
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Associative tolerance to the analgesic effects of morphine is most pronounced when morphine is paired with a distinctive context at a long interdose interval (IDI). In contrast, morphine administered at a short IDI promotes the development of non-associative tolerance and disrupts the acquisition of associative tolerance. The impact of IDI on the development of associative tolerance to opioids other than morphine has not been investigated previously. ⋯ The impact of IDI on the development of non-associative and associative fentanyl tolerance is consistent with findings obtained with morphine showing that conditions conducive to the development of non-associative tolerance disrupt the acquisition of associative tolerance. The cross-tolerance data, however, did not parallel previous research examining the cross-tolerance profiles of associative and non-associative morphine tolerance.