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Anesthesiology Mar 2004The duration of action of vecuronium is reduced in patients receiving phenytoin. In this study, the authors examined, simultaneously, the influence of phenytoin on both...
BACKGROUND
The duration of action of vecuronium is reduced in patients receiving phenytoin. In this study, the authors examined, simultaneously, the influence of phenytoin on both the pharmacokinetics and the pharmacodynamics of vecuronium.
METHODS
This study was approved by the institutional review board of the University of California, San Francisco, and patients gave written informed consent. Twenty-two patients, 11 taking phenytoin and all scheduled to undergo prolonged neurosurgical procedures with general anesthesia, participated in the study. In 12 patients (6 phenytoin, 6 control), vecuronium was infused at 7.5 microg x kg(-1) x min(-1) until the first response (T1) of each train-of-four decreased by 50%; in the remaining 10 patients (5 phenytoin, 5 control), 200 microg/kg vecuronium was infused over 10 min. Arterial blood samples were drawn at intervals over the next 5-7 h. Plasma concentrations of vecuronium and 3-desacetylvecuronium were measured by capillary gas chromatography. Pharmacokinetic and pharmacodynamic modeling was used to characterize the disposition of vecuronium and patient responses to it in the two groups.
RESULTS
Clearance was typically increased by 138% (95% confidence interval, 93-183%) in patients taking phenytoin. The effect of vecuronium was well described using a sigmoid Emax model. The concentration of vecuronium giving 50% twitch depression was increased 124% (45-202%) in patients taking phenytoin.
CONCLUSIONS
Chronic phenytoin therapy reduces the effect of vecuronium by mechanisms that include both increased vecuronium metabolism and reduced sensitivity of the patient to circulating concentrations of vecuronium.
Topics: Adult; Anticonvulsants; Biotransformation; Craniotomy; Drug Interactions; Female; Humans; Male; Middle Aged; Neuromuscular Junction; Neuromuscular Nondepolarizing Agents; Phenytoin; Supratentorial Neoplasms; Vecuronium Bromide
PubMed: 15108978
DOI: 10.1097/00000542-200403000-00024 -
Anaesthesia and Intensive Care Aug 1988
Topics: Adult; Anaphylaxis; Cyanosis; Female; Humans; Skin Tests; Vecuronium Bromide
PubMed: 2903693
DOI: No ID Found -
Anaesthesia and Intensive Care Feb 1987
Review
Topics: Atracurium; Humans; Neuromuscular Blocking Agents; Vecuronium Bromide
PubMed: 2882706
DOI: 10.1177/0310057X8701500110 -
Annals of Biomedical Engineering 1997This study presents an artificial neural network-based controller for regulating the level of induced paralysis during surgery using vecuronium bromide. The controller...
This study presents an artificial neural network-based controller for regulating the level of induced paralysis during surgery using vecuronium bromide. The controller uses the myogram of a rapid muscle contractions (called twitch) to generate the appropriate infusion rate. The controller is self-adjusting and can accommodate inter- and intrapatient drug response variations. It also withstands changes in the pure time delay and nonlinear pharmacokinetic parameters of the response. Another feature of the controller is that it does not depend on a priori knowledge of the patient response model. Computer simulations using pharmacokinetic and pharmacodynamic models showed negligible steady-state error and maximum percent undershoot averaged to 6.24%. The average infusion rate for 90% paralysis was 1.22 (microg x kg(-1) x min[-1]).
Topics: Computer Simulation; Equipment Design; Humans; Infusion Pumps; Infusions, Intravenous; Intraoperative Period; Models, Biological; Neural Networks, Computer; Neuromuscular Blockade; Neuromuscular Depolarizing Agents; Nonlinear Dynamics; Paralysis; Therapy, Computer-Assisted; Time Factors; Vecuronium Bromide
PubMed: 9395049
DOI: No ID Found -
Anesthesia and Analgesia Mar 1993Enhancement of a vecuronium neuromuscular blockade by prior administration of succinylcholine has been attributed to both pharmacokinetic and pharmacodynamic mechanisms....
Enhancement of a vecuronium neuromuscular blockade by prior administration of succinylcholine has been attributed to both pharmacokinetic and pharmacodynamic mechanisms. This study was performed to elucidate the mechanism of this interaction using decamethonium as the agonist drug. In five healthy patients undergoing gynecologic surgery, a cumulative dose-response relationship to vecuronium was determined following recovery from a neuromuscular block produced by 0.1 mg/kg intravenous decamethonium. In a second group of five similar patients, a cumulative dose-response curve to vecuronium was obtained without previous exposure to decamethonium. In this second group, at 30% recovery from a vecuronium block, 0.1 mg/kg decamethonium was administered. The results demonstrated a sevenfold increase in sensitivity (reducing the ED50 from 24 micrograms/kg to 3.5 micrograms/kg) to vecuronium when it was administered following recovery from decamethonium block, and a partial reversal lf the vecuronium block by decamethonium when the decamethonium was administered during recovery from vecuronium block. These findings support a pharmacodynamic explanation of the increased sensitivity to nondepolarizing muscle relaxants following recovery from an agonist neuromuscular block.
Topics: Adult; Decamethonium Compounds; Drug Synergism; Female; Humans; Middle Aged; Neuromuscular Junction; Surgical Procedures, Operative; Vecuronium Bromide
PubMed: 8095780
DOI: 10.1213/00000539-199303000-00033 -
Veterinary Anaesthesia and Analgesia Jul 2012To evaluate the potency and duration of three subparalyzing doses of vecuronium (VEC) in isoflurane-anesthetized horses.
OBJECTIVE
To evaluate the potency and duration of three subparalyzing doses of vecuronium (VEC) in isoflurane-anesthetized horses.
STUDY DESIGN
Prospective experimental study.
ANIMALS
Thirteen healthy adult horses undergoing arthroscopic surgery.
METHODS
During isoflurane anesthesia, horses received one of three doses of vecuronium (25, 50, or 100 μg kg(-1)). Neuromuscular transmission was monitored with acceleromyography (AMG) with train-of-four (TOF) stimulation of the radial nerve. Maximal depression of the first twitch (T1), and onset time were recorded for each dose. Recovery time to a TOF ratio >90% was also evaluated.
RESULTS
Vecuronium 25 μg kg(-1) produced no observable T1 depression in four horses. VEC 50 μg kg(-1) (n = 5) produced a maximal T1 depression of [median (min, max)] 41 (20, 71) % in four horses, and no neuromuscular block was seen in the fifth. VEC 100 μg kg(-1) was given to four horses and produced a T1 depression of 73 (64, 78) %. Of the four horses in which VEC 50 μg kg(-1) produced a measurable neuromuscular block, three recovered spontaneously 43 (40, 52) minutes after VEC administration; a fourth subject received edrophonium to reverse residual block at the end of the surgery. Spontaneous recovery after VEC 100 μg kg(-1) occurred by 112 minutes in one horse, and had to be facilitated by edrophonium in the remaining three horses, more than 2 hours after VEC had been given.
CONCLUSIONS AND CLINICAL RELEVANCE
A dose of 100 μg kg(-1) VEC in isoflurane anesthetized horses failed to produce complete paralysis. The partial neuromuscular block lasted at least 2 hours after this dose had been administered. Edrophonium was required to reverse the neuromuscular block in three of four horses. It is likely that more than 100 μg kg(-1) VEC would be necessary for complete neuromuscular blockade in horses, and that this dose will last >2 hours.
Topics: Anesthesia, Inhalation; Anesthetics, Inhalation; Animals; Arthroscopy; Dose-Response Relationship, Drug; Horse Diseases; Horses; Immobilization; Infusions, Intravenous; Isoflurane; Neuromuscular Nondepolarizing Agents; Vecuronium Bromide
PubMed: 22642379
DOI: 10.1111/j.1467-2995.2012.00720.x -
Anesthesia and Analgesia Oct 2013
Topics: Animals; Humans; Neuromuscular Blockade; Neuromuscular Blocking Agents; Neuromuscular Junction; Time Factors; Vecuronium Bromide
PubMed: 24057949
DOI: 10.1213/ANE.0b013e3182a21fe4 -
Anesthesia and Analgesia May 2000
Review
Topics: Anesthesia; Dose-Response Relationship, Drug; Humans; Intubation, Intratracheal; Neuromuscular Nondepolarizing Agents; Vecuronium Bromide
PubMed: 10809511
DOI: 10.1097/00000539-200005001-00002 -
Renal Failure 2012The concept of priming was introduced to facilitate a faster onset of nondepolarizing neuromuscular blocker for endotracheal intubation. Vecuronium is still very much in... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
The concept of priming was introduced to facilitate a faster onset of nondepolarizing neuromuscular blocker for endotracheal intubation. Vecuronium is still very much in use for most chronic renal failure patients posted for renal transplantation. The aim of this study was to examine the pharmacodynamics of vecuronium without and with preceding different small doses.
METHODS
One hundred chronic renal failure patients were assigned into four groups according to the used vecuronium priming regimen. The first control group (V(0)-group), where no priming dose was given. The other three priming groups (V(10)- , V(15)- , and V(20)-groups), where 10%, 15%, and 20% of ED(95) of vecuronium were administrated 5 min prior to the remaining intubating dose (2 × ED(95)) of vecuronium. Neuromuscular blockade was measured via acceleromyographic response of the ulnar nerve. Train-of-four (TOF) ratio was measured every minute during priming interval. Any unpleasant symptoms during precurarization were recorded. Lag time and onset time (from injection of intubating dose) were recorded. Endotracheal intubation condition was scored blindly. The duration and recovery times were also recorded.
RESULTS
The significant higher incidence of symptoms of paresis was encountered in V(20)-group in comparison with other two priming groups. TOF ratio started to decrease significantly at the first minute in V(20)-group, at the second minute in V(15)-group, and at the third minute in V(10)-group, till the fourth minute in the priming interval. Although TOF ratio was still above 0.90 in V(10)-group, it was below 0.80 in V(20)-group. Priming groups did not show significant intergroup difference in onset time. However, duration and recovery times were significantly longer in priming groups in comparison with V(0)-group without priming.
CONCLUSION
Priming the chronic renal failure patients with 10% of ED(95) vecuronium dose acquit the best pharmacodynamics with the fewest signs of muscle weakness. Larger vecuronium priming doses are unfavorable and convey no more clinical utility.
Topics: Adult; Female; Humans; Kidney Failure, Chronic; Male; Neuromuscular Nondepolarizing Agents; Preoperative Period; Prospective Studies; Vecuronium Bromide
PubMed: 22607043
DOI: 10.3109/0886022X.2012.684552 -
British Journal of Anaesthesia Aug 1987The distribution and kinetics of 14C-vecuronium were studied in rats and mice. 14C-Vecuronium accumulated rapidly in the liver. Both unchanged and metabolized vecuronium...
The distribution and kinetics of 14C-vecuronium were studied in rats and mice. 14C-Vecuronium accumulated rapidly in the liver. Both unchanged and metabolized vecuronium were excreted with the bile into the intestines and stomach. Reabsorption in the gut was probably responsible for an enterohepatic increase in radioactivity in the liver after one hour. Excretion through the kidneys increased continuously from low values after the initial peak. Binding in compartments with acid mucopolysaccharides such as cartilage, connective tissue etc., was less important. Blood-brain barrier and placenta were permeable only to a small degree.
Topics: Animals; Autoradiography; Carbon Radioisotopes; Female; Male; Mice; Organ Specificity; Pregnancy; Rats; Tissue Distribution; Vecuronium Bromide; Whole-Body Counting
PubMed: 2888475
DOI: 10.1093/bja/59.8.1044