Articles: analgesics.
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Each class (mu, delta kappa and epsilon) of opioid receptors has a characteristic pattern of distribution in the nervous system, which may, however, exhibit species differences. The effects of opioid receptor stimulation depend on the class of receptor involved, the localization of these specific receptors and the animal species under investigation. Endogenous ligands of opioid receptors, which include more than twenty peptides, derive from three precursors:proopiomelanocortin (beta-endorphin), proenkephalin A (enkephalins) and prodynorphin (dynorphins, neo-endorphins). ⋯ At this level, opioids reduce the activity of spinal neurones that convey the nociceptive messages. The classes of opioid receptors (certainly mu [mu 2?] and a, perhaps kappa) involved in this effect, and their pre- or postsynaptic location are not firmly established to date. Further developments on these points can be expected from the use of new ligands which are highly selective of the various classes of opioid receptors.(ABSTRACT TRUNCATED AT 250 WORDS)
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The patterns of recovery of patients who received seven different analgesic and sedative treatments were investigated with regard to the time at which the subjects awoke. For observations of the neurologic status, we developed a special score. ⋯ Piritramid/promethazine, pethidine/flunitrazepam, pethidine/promethazine and tramadol/methohexital required more time for awakening. On the basis of these results, we prefer to use the combination of fentanyl/midazolam, alfentanil/midazolam and ketamine/flunitrazepam to judge all patients' neurologic scores.
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Comparative Study
Electroencephalographic quantitation of opioid effect: comparative pharmacodynamics of fentanyl and sufentanil.
The authors compared the pharmacodynamics of sufentanil with those of fentanyl using the electroencephalogram (EEG) as a measure of opioid drug effect. Sixteen patients were given a rapid infusion of sufentanil (18.75 micrograms/min) during EEG recording. To quantitate the opioid-induced slowing of the EEG, the authors analyzed its power spectrum and calculated the spectral edge. ⋯ The time from injection to 50% maximal EEG slowing (T50) was calculated for each patient. The values for T50 for the two groups did not differ. The authors conclude that fentanyl and sufentanil have similar pharmacodynamic profiles, the former being 12 times more potent than the latter.
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Cahiers d'anesthésiologie · Jan 1991
Review[Mechanism of action and clinical use of opioids administered by the peripheral perineural route].
Experimental studies have shown that opioids could produce two types of effect on neuronal excitability. The first one, aspecific, is a local anesthetic action on the nerve fiber with a diminution of sodium and potassium conductance. ⋯ Clinical studies have proved that opioid injection in peripheral nervous trunks and specially in the brachial plexus produce a prolonged analgesia status in the post operative period but also and mostly in the chronic pain. The more liposoluble opioids like fentanyl and buprenorphine are the more effective.