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The Malaysian Journal of Pathology Dec 2009
Topics: Animals; Blood Platelets; Cholinesterase Inhibitors; Humans; Mice; Models, Animal; Movement; Platelet Aggregation; Pyridostigmine Bromide; Work
PubMed: 20514861
DOI: No ID Found -
Journal of Chromatography. B,... Apr 2001This study describes a chromatographic method for the determination of diazepam, an anxiolytic drug that is also used as an antidote against nerve agent seizures, its...
This study describes a chromatographic method for the determination of diazepam, an anxiolytic drug that is also used as an antidote against nerve agent seizures, its metabolites N-desmethyldiazepam, and temazepam, the anti-nerve agent drug pyridostigmine bromide (PB; 3-dimethylaminocarbonyloxy-N-methyl pyridinium bromide) and its metabolite N-methyl-3-hydroxypyridinium bromide in rat plasma and urine. The compounds were extracted using C18 Sep-Pak Vac 3cc (500 mg) cartridges and separated using isocratic mobile phase of methanol, acetonitrile and water (pH 3.2) (10:40:50) at a flow-rate of 0.5 ml/min in a period of 12 min, and UV detection ranging between 240 and 280 nm. The limits of detection for all analytes ranged between 20 and 50 ng/ml, while limits of quantitation were 100 ng/ml. Average percentage extraction recoveries of five spiked plasma samples were 79.1+/-7.7, 83.5+/-6.4, 83.9+/-5.9, 71.3+/-6.0 and 77.7+/-5.6, and from urine 79.4+/-7.9, 83.1+/-6.9, 73.6+/-7.7, 74.3+/-7.1 and 77.6+/-5.9 for diazepam, N-desmethyldiazepam, temazepam, pyridostigmine bromide, and N-methyl-3-hydroxypyridinium bromide, respectively. The relationship between peak areas and concentration was linear over the range between 100 and 1000 ng/ml. This method was applied to determine the above analytes following a single oral administration in rats as a tool to study the pharmacokinetic profile of each compound, alone and in combination.
Topics: Animals; Anti-Anxiety Agents; Calibration; Cholinesterase Inhibitors; Chromatography, High Pressure Liquid; Diazepam; Pyridostigmine Bromide; Quality Control; Rats; Rats, Sprague-Dawley; Reference Standards
PubMed: 11339294
DOI: 10.1016/s0378-4347(01)00040-8 -
CRNA : the Clinical Forum For Nurse... Feb 1995Pipecuronium Bromide (Arduan, Organon, Inc, West Orange) is a long-acting, nondepolarizing neuromuscular blocking agent. The efficacy of pyridostigmine 170 micrograms/kg... (Clinical Trial)
Clinical Trial
Pipecuronium Bromide (Arduan, Organon, Inc, West Orange) is a long-acting, nondepolarizing neuromuscular blocking agent. The efficacy of pyridostigmine 170 micrograms/kg intravenously (approximately 10 mg/70 kg) for reversing pipecuronium has not been reported. This study was performed to determine the time required to obtain a train-of-four (TOF) ratio of 0.7 after administration of pyridostigmine 140 micrograms/kg at 25% recovery of T1 after pipecuronium-induced neuromuscular blockade. Sixteen, American Society of Anesthesiology (ASA) I or II patients undergoing surgical procedures of at least 90 minutes, requiring intubation and muscle relaxation were included. Neuromuscular blockade was assessed using the Puritan-Bennett/Datex NMT 221 placed for ulnar nerve stimulation. Anesthesia was maintained with a nitrous oxide/narcotic technique and the use of potent inhalational anesthetics was avoided. The mean reversal time was found to be 16.14 minutes, with a minimum of 10.3 minutes and a maximum of 24.3 minutes. The standard error was +/- 1.05 minutes with a variance of 17.68 minutes.
Topics: Adult; Electric Stimulation; Electromyography; Female; Humans; Male; Monitoring, Intraoperative; Nerve Block; Neural Conduction; Pipecuronium; Pyridostigmine Bromide; Time Factors
PubMed: 7599547
DOI: No ID Found -
Xenobiotica; the Fate of Foreign... Mar 20081. The in vitro human plasma activity and liver microsomal metabolism of pyridostigmine bromide (PB), a prophylactic treatment against organophosphate nerve agent...
1. The in vitro human plasma activity and liver microsomal metabolism of pyridostigmine bromide (PB), a prophylactic treatment against organophosphate nerve agent attack, N,N-diethyl-m-toluamide (DEET), an insect repellent, and permethrin, a pyrethroid insecticide, either alone or in combination were investigated. 2. The three chemicals disappeared from plasma in the following order: permethrin > PB > DEET. The combined incubation of DEET with either permethrin or PB had no effect on permethrin or PB. Binary incubation with permethrin decreased the metabolism of PB and its disappearance from plasma and binary incubation with PB decreased the metabolism of permethrin and its clearance from plasma. Incubation with PB and/or permethrin shortened the DEET terminal half-life in plasma. These agents behaved similarly when studied in liver microsomal assays. The combined incubation of DEET with PB or permethrin (alone or in combination) diminished DEET metabolism in microsomal systems. 3. The present study evidences that PB and permethrin are metabolized by both human plasma and liver microsomal enzymes and that DEET is mainly metabolized by liver oxidase enzymes. Combined exposure to test chemicals increases their neurotoxicity by impeding the body's ability to eliminate them because of the competition for detoxifying enzymes.
Topics: Biotransformation; Butyrylcholinesterase; Cholinesterase Inhibitors; DEET; Drug Interactions; Esterases; Half-Life; Humans; Kinetics; Microsomes, Liver; Oxidoreductases; Permethrin; Pyridostigmine Bromide; Tetraisopropylpyrophosphamide
PubMed: 18274958
DOI: 10.1080/00498250701813230 -
Journal of Physiology, Paris 1998Pyridostigmine bromide (PB) promotes and then silences cholinergic muscle activity, and disrupts the junctional regions of muscle fibers and associated nerve terminals,...
Pyridostigmine bromide (PB) promotes and then silences cholinergic muscle activity, and disrupts the junctional regions of muscle fibers and associated nerve terminals, in organotypic mouse spinal cord-muscle cultures continuously treated with low concentrations of the drug for up to 14 days. Spontaneous muscle activity is restored within 1 week of drug removal.
Topics: Animals; Cholinesterase Inhibitors; Mice; Neuromuscular Junction; Neurotoxins; Organ Culture Techniques; Pyridostigmine Bromide; Spinal Cord
PubMed: 9789828
DOI: 10.1016/s0928-4257(98)80038-7 -
Pharmacology, Biochemistry, and Behavior Feb 1999This experiment was designed to assess the effects of acute and repeated administration of pyridostigmine bromide (a carbamate with prophylactic and therapeutic uses) on...
This experiment was designed to assess the effects of acute and repeated administration of pyridostigmine bromide (a carbamate with prophylactic and therapeutic uses) on response acquisition. Experimentally naïve, male Sprague-Dawley rats were exposed to a situation in which lever presses were either immediately followed by food-pellet presentation or after a 16-s resetting delay. Different groups of rats received either one acute administration of pyridostigmine bromide (10 mg/kg, by gavage) or repeated pyridostigmine administration for 7 days (1.5 mg/kg/day, by gavage). Other groups were treated with distilled water for the same period of time. Both acute and repeated pyridostigmine bromide administration decreased serum cholinesterase levels by approximately 50%, but neither treatment affected brain cholinesterase levels in our assay. Acute and repeated drug administration produced the same behavioral effects. Subjects exposed to the 0-s delay conditions obtained many more food pellets than those exposed to the 16-s delay conditions. Administration of pyridostigmine bromide delayed the onset of responding in some, but not all, of the subjects in the treated groups, independent of the delay condition to which they were exposed. Many more responses were observed on an inoperative lever during the 16-s delay conditions than during the 0-s delay conditions, especially during the 16-s delay condition in which subjects had received acute vehicle administration. Whether or not these effects of small doses of pyridostigmine bromide on response acquisition are of central or peripheral origin will need to be determined in future studies, as response acquisition in the present experiment may have been affected by pyridostigmine's effects on gastrointestinal functioning and/or motor activity.
Topics: Analysis of Variance; Animals; Cholinesterase Inhibitors; Drug Administration Schedule; Male; Persian Gulf Syndrome; Pyridostigmine Bromide; Rats; Rats, Sprague-Dawley; Reinforcement, Psychology
PubMed: 9972708
DOI: 10.1016/s0091-3057(98)00184-1 -
Clinical Pharmacology and Therapeutics 1972
Topics: Carbon Isotopes; Chromatography, Ion Exchange; Chromatography, Paper; Electrophoresis, Paper; Female; Humans; Iodides; Mass Spectrometry; Myasthenia Gravis; Pyridinium Compounds; Pyridostigmine Bromide; Radioisotope Dilution Technique; Spectrum Analysis; Ultraviolet Rays
PubMed: 4554662
DOI: 10.1002/cpt1972133393 -
Pharmaceutical Development and... Jun 2014Pyridostigmine has cardioprotective activity in both free and liposomal forms. This study aimed to develop and characterize liposomal formulations of pyridostigmine. For...
Pyridostigmine has cardioprotective activity in both free and liposomal forms. This study aimed to develop and characterize liposomal formulations of pyridostigmine. For this, a spectrophotometric ultraviolet (UV) analytical method, at 270 nm, was developed and validated to quantify liposomal pyridostigmine. The method was linear in ranges from 0.02 to 0.09 mg/mL. The accuracy of this method was determined intra- and inter-day; the results of coefficient of variation were of 1.73-2.72% and 0.32-2.32%, respectively. The accuracy ranged between 99.45% and 101.12%. The method has not changed by influence of liposomal matrix and demonstrated being able to quantify pyridostigmine in liposomes. Two liposomal multilamellar formulations were developed: a constituted by dystearoyl-phosphatidylcholine (DSPC) and cholesterol (CHOL) other by dioleil-phosphatidylcholine (DOPC) and CHOL. The encapsulation efficiency was determined as 23.4% and 15.4%, respectively. Analyses of size and release of pyridostigmine from the formulations were made and the results showed that the formulations are viable for future studies in vivo.
Topics: Chemistry, Pharmaceutical; Cholesterol; Drug Carriers; Liposomes; Particle Size; Phosphatidylcholines; Pyridostigmine Bromide
PubMed: 23682846
DOI: 10.3109/10837450.2013.795166 -
Nan Fang Yi Ke Da Xue Xue Bao = Journal... Oct 2011To compare the pharmacokinetic parameters of pyridostigmine bromide dispersible tablets and common tablets in rabbits.
OBJECTIVE
To compare the pharmacokinetic parameters of pyridostigmine bromide dispersible tablets and common tablets in rabbits.
METHODS
Twelve rabbits were given an oral dose (60 mg) of pyridostigmine bromide dispersible tablets or common tablets in a randomized crossover study. The plasma concentration of pyridostigmine bromide was determined by reversed-phase ion pair chromatography. The pharmacokinetic parameters were calculated using DAS2.1.1 software.
RESULTS
The pharmacokinetic parameters showed no significant differences in rabbit plasma between pyridostigmine bromide dispersible tablets and common tablets. The two tablets had a C(max) of 1.83∓0.08 mg·L(-1) and 1.68∓0.03 mg·L(-1), tmax of 2.33∓0.41 h and 2.58∓0.20 h, AUC(0-24) of 15.50∓0.62 mg·h·L(-1) and 15.14∓0.30 mg·h·L(-1), AUC(0-∞) of 15.82∓0.70 mg·h·L(-1) and 15.57∓0.32 mg·h·L(-1), respectively. The relative bioavailability F(0-24) was 102.38% and F(0-∞) was 101.61% for the dispersible tablets.
CONCLUSION
The two tablets are bioequivalent in rabbits.
Topics: Administration, Oral; Animals; Biological Availability; Female; Male; Pyridostigmine Bromide; Rabbits; Tablets; Therapeutic Equivalency
PubMed: 22027790
DOI: No ID Found -
Pacing and Clinical Electrophysiology :... Jun 2011The long-term efficacy of pyridostigmine, a reversible acetyl cholinesterase inhibitor, in the treatment of postural orthostatic tachycardia syndrome (POTS) patients...
BACKGROUND
The long-term efficacy of pyridostigmine, a reversible acetyl cholinesterase inhibitor, in the treatment of postural orthostatic tachycardia syndrome (POTS) patients remains unclear. We report our retrospective, single-center, long-term experience regarding the efficacy and adverse effect profile of pyridostigmine in the treatment of POTS patients.
METHODS
This retrospective study included an extensive review of electronic charts and data collection in regards to patient demographics, orthostatic parameters, side-effect profile, subjective response to therapy, as well as laboratory studies recorded at each follow-up visit to our institution's Syncope and Autonomic Disorders Center. The response to pyridostigmine therapy was considered successful if patient had both symptom relief in addition to an objective response in orthostatic hemodynamic parameters (heart rate [HR] and blood pressure). Three hundred patients with POTS were screened for evaluation in this study. Of these 300, 203 patients with POTS who received pyridostigmine therapy were reviewed. Of these 203 patients, 168 were able to tolerate the medication after careful dose titration. The mean follow-up duration in this group of patients was 12 ± 3 (9-15) months. Pyridostigmine improved symptoms of orthostatic intolerance in 88 of 203 (43%) of total patients or 88 of 172 (51%) who were able to tolerate the drug. The symptoms that improved the most included fatigue (55%), palpitations (60%), presyncope (60%), and syncope (48%). Symptom reduction correlated with a statistically significant improvement in upright HR and diastolic blood pressure after treatment with pyridostigmine as compared to their baseline hemodynamic parameters (standing HR 94 ± 19 vs 82 ± 16, P < 0.003, standing diastolic blood pressure 71 ± 11 vs 74 ± 12, P < 0.02). Gastrointestinal problems were the most common adverse effects (n = 39, 19%) reported. The overall efficacy of pyridostigmine in our study was seen in 42% of total patients or 52% of patients who could tolerate taking the drug.
CONCLUSION
The subgroup of POTS patients who can tolerate oral pyridostigmine may demonstrate improvement in their standing HR, standing diastolic blood pressure, and clinical symptoms of orthostatic intolerance.
Topics: Cholinesterase Inhibitors; Female; Humans; Male; Postural Orthostatic Tachycardia Syndrome; Pyridostigmine Bromide; Treatment Outcome; Young Adult
PubMed: 21410722
DOI: 10.1111/j.1540-8159.2011.03047.x