Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Atracurium besylate, a nondepolarizing neuromuscular blocking agent, was administered to 24 isoflurane-anesthetized domestic chickens. Birds were randomly assigned to 4 groups, and atracurium was administered at dosage of 0.15, 0.25, 0.35 or 0.45 mg/kg of body weight. The time of onset of twitch depression, the amount of maximal twitch depression, and the duration of muscular relaxation were recorded. After return to control twitch height, atracurium was further administered to achieve > 75% twitch depression. When twitch depression reached 75% during noninduced recovery, 0.5 mg of edrophonium/kg was administered to reverse the muscle relaxation. Throughout the experimental period, cardiovascular, arterial blood gas, and acid-base variables were monitored. The effective dosage of atracurium to result in 95% twitch depression in 50% of birds, (ED95/50) was calculated, using probit analysis, to be 0.25 mg/kg, whereas the ED95/95, the dosage of atracurium to result in 95% twitch depression in 95% of birds, was calculated by probit analysis to be 0.46 mg/kg. The total duration of action at dosage of 0.25 mg/kg was 34.5 +/- 5.8 minutes; at the highest dosage (0.45 mg/kg), total duration increased to 47.8 +/- 10.3 minutes. The return to control twitch height was greatly hastened by administration of edrophonium. Small, but statistically significant changes in heart rate and systolic blood pressure, were associated with administration of atracurium and edrophonium. These changes would not be clinically relevant. In this study, atracurium was found to be safe and reliable for induction of muscle relaxation in isoflurane-anesthetized chickens.
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PMID:Neuromuscular and cardiovascular effects of atracurium in isoflurane-anesthetized chickens. 147 19

Atracurium besylate, a nondepolarizing neuromuscular blocking agent, was administered as an infusion to 8 anesthetized cats in which neuromuscular blockade was assessed, using the train-of-four response. Once 50% depression of the first-twitch (T1) response was achieved, the infusion was held constant for 60 minutes before being discontinued and the recovery time was determined. The time for recovery was recorded as the time for the train-of-four (T4 ratio) to increase from 50% to 75%. After recovery, atracurium infusion was reinstituted and the cats were again maintained for 60 minutes at 50% depression. A single bolus of gentamicin sulfate (2.0 mg/kg of body weight) was administered IV, and the infusion was continued for another 60 minutes before it was discontinued and the time for recovery was recorded. Within 1 minute of gentamicin administration, the mean +/- SD T1 response decreased from 49 +/- 5% to 33 +/- 8% of baseline and the T4 ratio decreased from 28 +/- 19% to 14 +/- 11%. Peak effect occurred at 5 minutes, with a T1 response of 29 +/- 6% of baseline and a T4 ratio of 13 +/- 12%. By 60 minutes after gentamicin administration, the T1 response had increased to 38 +/- 7% of baseline and the T4 ratio had increased to 21 +/- 13%. The time for recovery significantly (P less than 0.03) increased from 9.9 +/- 3.4 minutes during the control study to 18.1 +/- 10.7 minutes during the gentamicin study. In this study, gentamicin potentiated the neuromuscular blockade induced by atracurium and increased the recovery time. Residual blockade, observed after gentamicin administration was reversed with edrophonium.
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PMID:Effect of gentamicin administration on the neuromuscular blockade induced by atracurium in cats. 224 Jul 89

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

Atracurium besylate, 2,2'-(3,11-dioxo-4,10-dioxatridecylene)-bis-[6,7-dimethoxy-1-(3,4-dimethoxy-benzyl)-2-methyl-1,2,3,4-tetrahydroisoquinolinium] dibenzenesulphonate, is one of a new series of competitive neuromuscular blocking agents. An i.v. dose of 0.25 mg kg-1 produced complete paralysis in anaesthetized cats, dogs and rhesus monkeys; paralysis was of medium duration and was readily antagonized by neostigmine. Vagal blockade occurred only after doses 8--16 times greater than the full neuromuscular paralysing dose and effects on sympathetic mechanisms were minimal. Hypotension and bradycardia were evident after supramaximal doses of 4 mg kg-1 i.v. and these effects, together with circulatory depression, were probably attributable to histamine release. In vitro studies have shown that the non-enzymic decomposition of atracurium by "Hofmann Elimination" was enhanced by increasing pH. In vivo neuromuscular paralysis was significantly reduced when the arterial pH was increased. There were indications that neither the liver nor the kidney plays a major role in the metabolism and elimination of unchanged drug. These results are of sufficient interest to merit the evaluation of atracurium in anaesthetized man.
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PMID:The pharmacology of atracurium: a new competitive neuromuscular blocking agent. 616 27