Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Atracurium besylate, a nondepolarizing neuromuscular blocking agent, was administered by infusion to 10 cats that were anesthetized with isoflurane and oxygen to allow transplantation of a myocutaneous flap. Five of the cats were given cyclosporine (20 mg/kg of body weight, PO q 12 h in divided doses) for 2 days prior to anesthesia, and prednisolone (0.25 mg/kg, PO) on the morning of surgery. The other 5 cats were not given either drug. Neuromuscular blockade was assessed, using the train-of-four stimulation, and throughout surgery, the infusion rate was adjusted to maintain the first-twitch response (T1) at 90 to 95% depression from baseline. At completion of surgery, atracurium was discontinued, and the infusion rate and the time for recovery (the time for the train-of-four ratio to increase from 50 to 75%) were recorded. Once the train-of-four ratio had been stable for 10 minutes, edrophonium (0.5 mg/kg), a cholinesterase inhibitor, was administered IV, and neuromuscular blockade was monitored for another 10 minutes. Mean (+/- SD) duration of the atracurium infusion was 302.1 +/- 70.5 minutes for the control group and was 323.9 +/- 61.7 minutes for the cats given cyclosporine and prednisolone. In the cats of the control group, the infusion rate required to induce 90 to 95% T1 depression from baseline was 3.7 +/- 0.7 micrograms/kg/min. This rate was not significantly different from that of 2.8 +/- 1.2 micrograms/kg/min in cats given cyclosporine and prednisolone. Significant difference in recovery time was not evident between the control group and the treated group (6.4 +/- 4.5 minutes vs 6.2 +/- 2.5 minutes).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Atracurium administration, as an infusion, to induce neuromuscular blockade in clinically normal and temporarily immune-suppressed cats. 225 41

The physiological changes that occur with increasing age can have significant effects on the pharmacokinetics of neuromuscular-blocking drugs. Changes in cardiac output can affect drug distribution and therefore the speed of onset of neuromuscular block. A decrease in muscle mass and increase in body fat with age can also affect their distribution. The deterioration in renal and hepatic function associated with aging affects the clearance and elimination of many neuromuscular-blocking drugs. The effects of these physiological changes on the pharmacokinetics of neuromuscular-blocking agents may not become apparent clinically in healthy individuals until the age of at least 75 years. There is very little evidence to suggest any alteration in the sensitivity of the neuromuscular junction to neuromuscular-blocking drugs with increasing age. Neuromuscular-blocking drugs that undergo a significant degree of organ-dependent elimination, such as pancuronium bromide, vecuronium bromide, rocuronium bromide and doxacurium chloride, may have a significantly prolonged duration of action in elderly patients. These drugs can be used safely in elderly patients if the anaesthetist is aware of their altered pharmacokinetics in this patient group. Appropriate changes must be made to drug dosage and dose intervals. As the pharmacokinetic changes can be unpredictable, monitoring of neuromuscular block is strongly advised when using these drugs in such patients. The risk of residual block occurring postoperatively after the use of pancuronium bromide increases with age. The duration of action of mivacurium chloride may also be prolonged in the elderly; this change has not been demonstrated to be a result of an alteration in plasma cholinesterase activity. In contrast, there is no evidence of an alteration in the action of suxamethonium chloride (succinylcholine chloride) with increasing age. Atracurium besilate and cisatracurium besilate undergo predominantly organ-independent elimination. Onset of block with these two drugs may be prolonged in the elderly, but their clinical duration of action does not alter significantly with age, making them particularly suitable for use in this patient group. Although atracurium besilate may cause histamine release, there is little evidence of it producing haemodynamic changes in the elderly. Its (1R,1R')-isomer, cisatracurium besilate, has very little direct or indirect cardiovascular effect and is, therefore, the most suitable nondepolarising agent to use in elderly patients.
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PMID:Selecting neuromuscular-blocking drugs for elderly patients. 1253 13