Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “THIOPENTAL”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources
PubMed1981

Effects of thiopental on regulatory mechanisms of brain energy metabolism.

After administration of thiopental to artificially ventilated rats, the EEG, cerebral metabolism, intracellular distribution of hexokinase activity and the thiopental concentration in brain was measured. Considering the EEG changes, the time course of thiopental action was divided into an initial stage with increased beta activity and a following second stage with reduced beta activity. The glucose-6-phosphate concentration significantly increased in the first stage and fell again to the control level with the beginning of the second stage. Furthermore, during the second stage the glucose level increased and the hexokinase activity shifted from the mitochondrially bound form to the soluble form. From these results the following conclusions were drawn: Phosphofructokinase activity appeared inhibited only during the initial stage. During the second stage comparable to the stage of surgical anesthesia, thiopental solubilizes bound hexokinase activity inhibiting thereby energy metabolism.

Amino Acids↗
PubMed1977

Solubilization of brain mitochondrial hexokinase by thiopental.

The control of hexokinase activity probably is accomplished by regulating the partitioning of the enzyme between soluble and particulate forms, the latter being more active. In the present investigation we have examined the thiopental effect on the cerebral hexokinase distribution. In anesthesia, after administration of thiopental to male Sprague Dawley rats, the increase of the soluble fraction of hexokinase was dose dependent. The change in the intracellular hexokinase distribution was reversible and lasted as long as general anesthesia existed. Also in experiments in vitro a solubilization of the mitochondrial hexokinase by thiopental (0.1--1 mM) occurred; it was depending on drug concentration. An inhibition of hexokinase was found neither in the total brain extract, nor in the soluble or the particulate fraction. The results suggest that phosphorylation of glucose in brain may be suppressed in anesthesia by shifting hexokinase activity from a more active mitochondrial form to its less active soluble form. This effect seems to be caused by a direct action of thiopental and is obviously correlated with anesthesia.

Animals↗
PubMed1982

Relationship between brain mitochondrial hexokinase and neuronal function: comparable effects of 2-deoxy-D-glucose and thiopental.

Mitochondrially bound brain hexokinase is solubilized by anesthetics and this effect has been suggested to contribute to anesthesia. In the present investigation the influence of the metabolic inhibitor 2-deoxy-D-glucose (2-DOG) was studied. An isolated rat brain preparation was used to avoid the contribution of peripheral reactions. Isolated rat brains were perfused for 45 min with media containing 4 mmol/l glucose, 10 mmol/l 2-DOG and/or 0.4 mmol/l thiopental. The EEG was monitored and acetylcholine, 2-DOG and its 6-phosphate, as well as the intracellular distribution of hexokinase activity were determined in brain tissue. Soluble hexokinase activity in brain cortex was enhanced by 2-DOG, as also by thiopental, and even more pronounced by both drugs used together, Results from in vitro experiments suggest that solubilization of mitochondrial hexokinase after 2-DOG is mediated by intracellularly accumulated 2-DOG-6-phosphate. 2-DOG produced a significant impairment of neuronal activity, revealing EEG patterns similar to those caused by thiopental anesthesia. Cortical acetylcholine levels were elevated by 2-DOG, as well as by thiopental, and again both drugs showed an additive effect when used in combination. This effect which may be the result of an inhibition of acetylcholine release, was also detectable in mice in vivo after 5 g 2-DOG/kg i.p., whereas the same dose of 3-O-methylglucose had no effect. The results provide further evidence that mitochondrial hexokinase may be involved in the relationship between cerebral metabolism and brain function.

Animals↗
PubMed1989

Placental transfer and tissue distribution of thiopental in the pregnant rat.

The pharmacokinetic profile of thiopental was studied in pregnant rats after an iv bolus dose of 15 mg/kg. The unbound concentration-time profile of the drug in maternal plasma, placenta, fetal brain, fetal carcass, and amniotic fluid was described, developing an adequate pharmacokinetic model. Maternal plasma levels of thiopental fell rapidly after injection, distributing into tissues (half-life of distribution phase averaged 3 min). Thiopental crossed the placenta and entered the fetal body (brain included) and amniotic fluid. Peak levels were seen within 10 min of injection and declined in all tissues parallel to maternal plasma (rate constant range 0.012-0.017 min-1). The concentrations of drug in the fetal unit were smaller than in the central compartment and maternal plasma. However, the absolute transfer ratios (calculated using the pharmacokinetic parameters obtained from the model) and the relative exposure ratios (as the ratio of the area under the unbound concentration-time curve in tissue to that in maternal plasma) suggested that fetuses were exposed to a potentially efficacious level of the drug. The model formulated to describe the tissue distribution of thiopental may offer a useful approach for analysis of the kinetic profile of other compounds administered during pregnancy or at delivery in rats and other species.

Amniotic Fluid↗
PubMed1990

Effects of thiopental on resistance vessels in cat skeletal muscle.

Barbiturates are used clinically as anaesthetics and to reduce raised intracranial pressure. One side effect is hypotension, usually ascribed to a depression of cardiac contractility, while their effects on the resistance vessels are more controversial: both vasodilation and vasoconstriction have been described. This study analyzes the effects of thiopental on basal vascular tone in the cat skeletal muscle. We found that total resistance increased by almost 20% at low (50 mumol/l) and decreased down to about 50% of control at high (350 mumol/l) plasma concentrations of thiopental. The vasoconstriction dominated in the large arterioles (i.d. greater than 25 microns) and the vasodilation in the small arterioles (i.d. less than 25 microns). A dose-dependent inhibition of myogenic vascular reactivity (here defined as the maximum resistance increase to a transient rise in transmural pressure) coincided with the vasodilation. Autoregulation of blood flow was depressed by thiopental. During vasoconstriction there was a net transcapillary fluid absorption and during vasodilation a net fluid filtration. The fluid movements could be ascribed to variations in capillary hydrostatic pressure. If applicable to the cerebral circulation these results suggest that thiopental at high plasma concentrations might induce, instead of reduce, interstitial brain oedema.

Animals↗
PubMed1986

Enhancement of vasoconstrictor responses to thiopental and barium chloride by intraluminal treatment with saponin in isolated canine mesenteric arteries.

Using a cannula-insertion method for isolated arteries, the effects of thiopental, barium chloride, and prostaglandin F2 alpha were investigated on isolated canine mesenteric arteries with and without saponin treatment. Thiopental caused a vasoconstriction in a dose-related manner. The observed vasoconstriction was not influenced by phentolamine in doses which inhibited norepinephrine-induced vasoconstriction. After intraluminal saponin treatment, thiopental- and barium chloride-induced constrictions were significantly enhanced, but prostaglandin F2 alpha-induced constriction was not potentiated. It is suggested that vasoconstrictor responses to thiopental and barium chloride may be enhanced by an increase in calcium influx after disrupting the endothelium of the artery.

Animals↗
PubMed1999

Laryngeal mask insertion using thiopental and low dose atracurium: a comparison with propofol.

PURPOSE: To compare the laryngeal mask airway (LMA) insertion conditions produced by propofol and a thiopental - low dose atracurium combination. METHODS: In a randomized controlled double blind study, 120 premedicated patients were allocated into four groups. After pre-oxygenation, anesthesia was induced as follows: 1 microg x kg(-1) fentanyl, 2.5 mg x kg(-1) propofol (group I); 1 microg x kg(-1) fentanyl, 5 mg x kg(-1) thiopental (group II); 1 microg x kg(-1) fentanyl, 5 mg x kg(-1) thiopental, 0.05 mg x kg(-1) or 0.1 mg x kg(-1) atracurium (groups III and IV respectively). The LMA was inserted by a blinded anesthesiologist who also assessed the following insertion conditions on a three point scale; jaw relaxation, biting, gagging, coughing, presence of laryngospasm, adequacy of airway patency, number of attempts at insertion and overall insertion conditions. RESULTS: There was no difference in insertion conditions between groups I, III and IV. Group II produced the worst overall conditions (P<0.05). There were no differences in hemodynamic changes and apnea times between all four groups. CONCLUSION: The combination of fentanyl-thiopental with low dose atracurium (0.05 or 0.1 mg x kg(-1)) provided conditions comparable with those of propofol for LMA insertion.

Adult↗
PubMed1986

Aminophylline shortens thiopental sleep-time and enhances noradrenergic neurotransmission in rats.

We investigated the effect of aminophylline on thiopental sleep-times and monoamine neurotransmitter turnover rates in discrete brain areas. Aminophylline-treated rats had shorter thiopental sleep-times than saline-treated controls. Noradrenergic neurotransmission was greater following aminophylline treatment in thiopental-anesthetized rats in all brain areas while turnover in other monoaminergic pathways was unchanged. These data suggest that acute aminophylline treatment increases central noradrenergic neurotransmission which pharmacodynamically diminishes the hypnotic response to thiopental.

Aminophylline↗
PubMed1992

The comparative effects of propofol, thiopental, and diazepam, administered intravenously, on pentylenetetrazol seizure threshold in the rabbit.

The anticonvulsant effects of propofol, thiopental, and diazepam, administered intravenously, on pentylenetetrazol (PTZ) seizure threshold were studied and compared in the rabbit. The PTZ seizure threshold determined in various rabbit groups during the control phase of conducted experiments, was found to be in the range of 10.1 +/- 2.0 to 13.5 +/- 3.7 mg/kg. Intravenous administration of comparable doses of propofol, thiopental, and diazepam resulted in marked and significant increases in PTZ seizure threshold. At all administered doses (1.25-10.0 mg/kg), propofol was found to be more effective than thiopental in increasing the PTZ threshold dose. However, the anticonvulsant effects of diazepam were more marked than those of propofol, except at a dose of 10 mg/kg where both agents exhibited equipotent activities. These data demonstrate that propofol enjoys a considerable degree of anticonvulsant activity in the rabbit. This anticonvulsant action is greater than that of thiopental at doses ranging from 2.5 to 10 mg/kg and equipotent with diazepam at the 10 mg/kg dose.

Animals↗
PubMedDate not supplied

Cost analysis of propofol versus thiopental induction anesthesia in outpatient laparoscopic gynecologic surgery.

This study investigated the cost of propofol versus thiopental anesthesia in 243 patients who underwent outpatient laparoscopic gynecologic surgery. Patients records were analyzed for medication use, duration of surgery, anesthesia, recovery room stay, and associated costs. Despite the higher drug cost for propofol, the total mean cost was $273.00 less per patient for patients receiving propofol induction anesthesia. Extension of these data translates into cost savings of approximately $7900.00 if propofol had been used for all patients. Although the duration of surgery for the propofol group was shorter by nearly 12 minutes, the anesthesia duration and recovery room stay were both longer for the thiopental group, reflecting the longer duration of action of thiopental. Although the realized cost savings of drugs, surgery, anesthesia, and recovery time when propofol versus thiopental is used for outpatient laparoscopic gynecologic surgery are relatively small on an individual patient basis, cost savings may become more significant if larger patient populations are studied.

Adult↗
PubMedDate not supplied

Three balanced anesthetic techniques for neuroanesthesia: infusion of thiopental sodium with sufentanil or fentanyl compared with inhalation of isoflurane.

STUDY OBJECTIVE: To compare emergence from anesthesia and the hemodynamic and respiratory depressant effects of thiopental sodium infusion plus sufentanil or fentanyl with those of isoflurane as the primary component of a balanced technique for neuroanesthesia. DESIGN: Randomized, double-blind, prospective study. SETTING: University hospital and its affiliated Veterans Affairs Medical Center. PATIENTS: Thirty patients undergoing elective craniotomy for aneurysm or tumor. INTERVENTIONS: Thiopental with infusion of sufentanil 0.1 microgram/kg/hr, thiopental with infusion of fentanyl 1 microgram/kg/hr, or inhalation of 0.25% to 2% isoflurane as the major component of a balanced anesthesia technique that included nitrous oxide (N2O) and vecuronium (potency ratio of sufentanil to fentanyl, 10:1). MEASUREMENTS AND MAIN RESULTS: Intraoperative stress response (as indicated by intraoperative hypertension) was said to be the percentage of time the patient required administration of an antihypertensive drug, measuring from the first dose of thiopental to discontinuation of N2O at the end of the procedure, excluding any period of induced hypotension. Rapidity of emergence was measured by the number of minutes from discontinuation of N2O to first opening of the eyes on command. Adequacy of spontaneous ventilation was evaluated by determining partial pressure of arterial carbon dioxide 1, 2, and 3 hours after discontinuation of N2O. Extent of vasoactive drug administration for control of intraoperative hypertension (as determined by the clinicians caring for the patients) was described by minutes of vasodilator infusion and milligrams of propranolol or labetalol administered. The frequency of postoperative hypertension was defined as the number of patients in each group who required medication for postoperative hypertension. No significant differences in variables were found for thiopental/sufentanil, thiopental/fentanyl, or isoflurane when these drugs were used with N2O and vecuronium. CONCLUSIONS: Any one of these balanced anesthetic techniques appears appropriate for craniotomy.

Adult↗
PubMedDate not supplied

Comparison of pregnancy rates following gamete intrafallopian transfer (GIFT) under general anesthesia with thiopental sodium or propofol.

STUDY OBJECTIVE: To determine whether the pregnancy rate for gamete intrafallopian transfer (GIFT) patients who received thiopental sodium was different from the pregnancy rate for patients who received propofol for the induction of general anesthesia. DESIGN: Retrospective review of clinical records. SETTING: Private outpatient infertility clinic. PATIENTS: Two hundred eighty-two consecutive GIFT procedures performed on 230 patients with infertility. INTERVENTION: Patients undergoing GIFT were divided into two groups on the basis of whether they received thiopental or propofol for induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: Clinical pregnancy following each GIFT procedure was assessed by multiple-serum beta human chorionic gonadotropin and ultrasound determinations. The pregnancy rates of 24.6% and 25.8% for the thiopental and propofol groups, respectively, were not significantly different. CONCLUSIONS: The pregnancy rate following GIFT for patients given propofol for induction of general anesthesia did not differ from that for patients given thiopental.

Adult↗
PubMed2004

Detection of thiopental in the steroid fraction of serum from neonates following maternal exposure.

To follow up an investigation which studied effects of antenatal dexamethasone therapy on neonatal respiratory performance in multifetal gestations, neonatal serum steroids were determined by HPLC. A major peak (X) whose retention time coincided with that of dexamethasone was observed in many, but not all, serum samples. However, there was no correlation between the neonates whose serum samples displayed this X-peak and the mothers who had actually received the steroid therapy, indicating that the X-substance was not dexamethasone. An alternate mobile phase was employed which separated the X-substance and dexamethasone validating the indication. Among ten clinical conditions of the neonate birth, the X-substance was found to correlate only with the mothers who had the cesarean operation for delivery, suggesting that the substance was not necessarily a steroid. Four anesthetic agents used for cesarean operations were studied; the X-substance was identified as thiopental using a LC/MS technique. This was based on the same retention times, the same negative ions at m/z 240.9 and the same daughter ions at m/z 100.8 between the two substances. Thus, caution must be exercised when HPLC is employed to study serum steroids of patients who have previously been exposed to thiopental. Moreover, recent reports have shown that thiopental affects certain metabolic reactions in the rat; the present findings also suggest a need for further investigations of thiopental effect on neonates.

Dexamethasone↗
PubMed2006

Fulminant hyperammonaemia induced by thiopental coma in rats.

Fulminant hyperammonaemia as a threshold effect of coma-inducing dose of sodium thiopental has been revealed in rats. Blood ammonia content increased progressively after the introduction of 1.0 LD(50) (but not 0.8 LD(50)) of sodium thiopental three times in 3h and five times in 18h. The urinary ammonia excretion was not impaired while the volatilization of ammoniac from the body of ST-treated rats was higher, giving evidence of the augmentation of ammonia production. Blood urea increased by one third despite of insignificant alterations of haematocrit and blood creatinine. Ammonia hyperproduction in the digestive tract could result from gastrointestinal stasis, which has been verified by roentgenography and confirmed by correlation of hyperammonaemia with the stool retardation. In thiopental coma rats the slope of a dose-dependent increase of the blood ammonia and the blood urea after the intraperitoneal injection of ammonium acetate did not exceed that in intact animals. So the ammonia hyperproduction in the digestive tract could be the main contributing cause of fulminant hyperammonaemia in rats with thiopental coma and thus be involved into pathogenesis of the coma.

Acetates↗
PubMed1982

Thiopental modification of ischemic spinal cord injury in the dog.

Spinal cord ischemia was produced in male mongrel dogs by permanent occlusion of the infrarenal aorta. All animals were anesthetized with a mixture of nitrous oxide and 1.5% halothane. Group 1 animals were the controls. Group 2 animals were pretreated, 30 minutes prior to aortic occlusion, with sodium thiopental, 20 mg per kilogram of body weight, over 5 minutes, followed by an infusion of 10 mg/kg/hr for 2 1/2 hours. Groups 3 animals received the identical dose of sodium thiopental and, in addition, received mannitol, 1 gm/kg, and methylprednisolone 1 mg/kg. There were no differences in hemodynamic data or arterial blood gases among the groups, except that the thiopental bolus caused a transient reduction in mean arterial pressure. Ninety percent of Group 1 animals were paraplegic, while only 30% of Group 2 and 40% of Group 2 animals were paraplegic. The difference in the incidence of paraplegia in Groups 2 and 3 compared with Group 1 was statistically significant (p less than 0.05). Therefore, thiopental significantly decreased the incidence of paraplegia, while methylprednisolone and mannitol did not enhance its protective effect.

Animals↗
PubMed1999

Decreased glutamate metabolism in cultured astrocytes in the presence of thiopental.

The effect of thiopental on glutamate metabolism was studied by 13C magnetic resonance spectroscopy. Cerebral cortical astrocytes were incubated with 0.5 mM [U-13C]glutamate for 2 hr in the presence of 0.5 or 1 mM thiopental. Labeled glutamate, glutamine, aspartate, and glutathione were observed in cell extracts, and glutamine, aspartate, and lactate in the medium. Not only present in the medium was uniformly labeled glutamate, but also glutamate derived from the tricarboxylic acid (TCA) cycle, and thus glutamate release could be detected. The amounts of [U-13C]glutamate and unlabeled glucose taken up by astrocytes were unchanged in the presence of 0.5 mM thiopental and decreased to about 50% and 80%, respectively when the concentration was increased to 1 mM. The amounts of most metabolites synthesized from [U-13C]glutamate were unchanged in the presence of 0.5 mM thiopental, but decreased [U-13C]glutamine, [U-13C]aspartate, and [U-13C]lactate were observed in the 1 mM group. Surprisingly, the amounts of [1,2,3-13C]glutamate, [2,3-13C]aspartate, and [3,4-13C]aspartate (2nd turn via the TCA cycle) were unchanged. However, this was not the case for [1,2-13C]lactate and [2,3-13C]lactate. Such variations indicate cellular compartmentation, possibly caused by a heterogeneous glutamate concentration within the cells affecting TCA cycle turnover rates differently.

Anesthetics, Intravenous↗
PubMed2001

Fast, simple and cost-effective determination of thiopental in human plasma by a new HPLC technique.

BACKGROUND: Thiopental is an anaesthetic drug that is largely used in both short-term and long-term infusion. After long-term infusion of thiopental, non-linear and inter-individual-dependent pharmacokinetics occur because of the saturation and/or induction of the metabolism. Clinical monitoring is important so that therapeutic adjustments can be made in many of the different pharmacological treatments, especially when long-term infusion is required. We describe a new, rapid HPLC method for the determination of plasma thiopental. METHODS: Sample preparation involved precipitation of plasma proteins using a mixture of methanol, zinc sulfate and ethylene glycol, and containing the internal standard 5-ethyl-5-p-tolyl-barbituric acid. After adding trichloroacetic acid, the sample was centrifuged and the supernatant was injected into a C(18) reversed-phase column. The mobile phase used was water-methanol-acetonitrile (50:40:10, v/v). The eluent was monitored at 290 nm. RESULTS: The calibration curve was linear from 0.2 to 100 microg/mL. Precision, calculated as the coefficient of variation (%), was in the range of 3.62-0.70% for the within-day assay and 5.77-1.51% for the between-day assay. The absolute recoveries obtained from supplemented samples were never less than 100%. CONCLUSIONS: This technique shows good reliability and seems to be suitable for a very fast and simple therapeutic monitoring of plasma thiopental.

Anesthetics, Intravenous↗
PubMed1987

Follicular fluid concentrations of thiopental and thiamylal during laparoscopy for oocyte retrieval.

Because access into ovarian tissue of drugs used during anesthesia may be potentially harmful to the oocyte and/or follicular structure, we measured concentrations of thiopental (n = 15) and thiamylal (n = 9) in follicular fluid (FF) aspirates of 24 patients who underwent laparoscopic oocyte retrieval. In both groups, measurable amounts of the respective drug were found in all FF aspirates. Within individual patients, plasma concentrations of both drugs declined during the period of sampling between initial and final follicular aspiration. The mean plasma drug concentration was 7.99 +/- 3.97 micrograms/ml in the thiamylal group and 4.13 +/- 0.90 micrograms/ml in the thiopental group. Mean drug concentrations in FF were similar in both groups (thiopental 1.62 +/- 0.61 micrograms/ml; thiamylal 1.67 +/- 0.83 micrograms/ml). The mean FF/plasma concentration ratio during the sampling period was greater in the thiopental group (0.41 +/- 0.19) as compared with the thiamylal group (0.22 +/- 0.14). Several steps in the clinical management of these patients can be taken to reduce exposure of oocytes to drugs used during anesthesia.

Adult↗