Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026837 (muscle rigidity)
 1,077 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several fentanyl analogs (Bagley et al., 1989, J. Med. Chem. 32, 663) were compared to fentanyl and morphine for their effects on respiratory depression as determined by arterial blood gas (pH, pCO2 and pO2) measurements. Fentanyl (0.1 mg/kg), morphine (10 mg/kg), #16 (1-phenethyl-4-[N-(pyridin-2-yl)-N-(methoxymethylcarbonyl)amino] piperidine, 1 mg/kg), #17 (1-phenethyl-4-[N-(pyridin-2-yl) -N-(2-furoyl)amino]piperidine, 0.5 mg/kg) and #29 (1-phenethyl-4-[N- (pyrimidin-2-yl)-N-(methoxy-methylcarbonyl) amino]piperidine, 10 mg/kg) produced significant respiratory depression in rats. Pretreatment with the mu1-opioid receptor selective antagonist, naloxonazine (10 mg/kg), blocked the respiratory effect of fentanyl and its analogs, but not that of morphine. The results suggest that the mu1-opioid receptor plays an important role in the respiratory effects of fentanyl and its analogs. Hence, the mechanism of fentanyl-induced respiratory depression appears to be distinct from that produced by morphine. The most likely explanation for this difference is the possible contribution of muscle rigidity and catalepsy to the observed changes in blood gas parameters caused by the fentanyl analogs, while the respiratory depression of morphine, measured by these same parameters, appears to be independent of its effect on muscle rigidity.
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PMID:Evidence for mu1-opioid receptor involvement in fentanyl-mediated respiratory depression. 889 2

Remifentanil is a potent mu-opioid receptor agonist and has some unique pharmacokinetic characteristics compared to other anilidopiperidine opioids (e.g. fentanyl, alfentanil, and sufentanil). As remifentanil is metabolised rapidly by nonspecific esterases that are widespread throughout the plasma and tissuses, its duration of action is very short. It is cleared very rapidly, and its clearance is not affected by renal and hepatic function. The context-sensitive half-time of remifentanil remains consistently short, even after administration for a long time. Consequently, emergence is quick even after anesthesia of long duration. As other piperidine opioids, remifentnil has some adverse effects such as respiratory depression, muscle rigidity, bradycardia, and nausea as well as vomiting. Because of the rapid dissipation of analgesic effect following remifentanil discontinuation, postoperative analgesia should be provided before or soon after anesthesia using longer-acting opioid analgesics, non-opioid analgesics, or local as well as regional anesthesia.
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PMID:[Remifentanil]. 1685 41