Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P46098 (5-HT3 receptor)
 2,290 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

5-Hydroxytryptamine (5-HT) causes antinociception via presynaptic 5-HT3 (5-HT subtype 3) receptors on primary afferent nociceptive neurones in the spinal cord dorsal horn. Therefore, ondansetron (a 5-HT3 receptor antagonist) may increase the perception of a noxious stimulus or decrease the effects of concurrently administered antinociceptive drugs. Using a randomized, double-blind, crossover study design, we have tested this hypothesis in eight healthy volunteers who, on three different days, received either ondansetron and placebo, ondansetron and alfentanil or placebo and alfentanil. Experimental pain was induced with heat, cold, mechanical pressure and electrical stimulation. Ondansetron alone did not change the response to any of the experimental tests, but alfentanil and the combination ondansetron-alfentanil significantly changed the response compared with ondansetron alone. There was no difference between alfentanil alone and the combination ondansetron-alfentanil. We conclude that ondansetron does not change the response to pressure, heat, cold or electrical nociceptive stimuli or antagonize the analgesic effect of alfentanil.
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PMID:Ondansetron does not inhibit the analgesic effect of alfentanil. 794 58

Ondansetron is a competitive serotonin 5-HT3 receptor blocker that has proved useful in the prevention of emesis due to cisplatin and other cancer chemotherapeutic agents. In a randomized, open-label, crossover study in 24 healthy male subjects, the relative bioavailability of a single 8-mg tablet was compared with that of an 8-mg solution using the two one-sided t-tests. The tablet and solution formulations were bioequivalent, as confirmed by similarities in mean Cmax (26.3 vs 27.7 ng/mL), Tmax (1.79 vs 1.70 h), and AUC (166.0 vs 167.3 ng.h/mL) values. In another randomized, open-label, crossover study in 12 healthy male subjects, the bioavailability of an 8-mg ondansetron tablet administered 5 min after a standard meal was slightly but significantly greater than in fasted subjects, as indicated by comparative mean AUC values [201.4 ng.h/mL (fed) vs 172.5 ng.h/mL (fasted)]. Coadministration of a magnesium hydroxide/aluminum hydroxide antacid did not affect the bioavailability of the ondansetron tablet.
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PMID:Ondansetron absorption in adults: effect of dosage form, food, and antacids. 796 57

The involvement of 5-hydroxytryptamine (5-HT) in gastric function and mucosal damage has been defined. 5-HT also potentiates lesion formation in animals. The current study investigated further whether these actions are mediated through 5-HT3 receptors in rats. Ondansetron, a 5-HT3 receptor antagonist, was given subcutaneously, 2 or 4 mg/kg, 30 min before the gastric parameters were measured. The higher dose of ondansetron, 4 mg/kg, significantly increased gastric mucosal blood flow (GMBF) and also basal acid and Na+ secretion. However, it did not affect pepsin output. 5-HT time dependently reduced GMBF and pepsin secretion, but not that of acid and Na+. These actions were not altered by ondansetron pretreatment. The drug, however, dose dependently reduced ethanol-induced gastric mucosal lesions in the 5-HT-treated animals. These findings indicate that 5-HT3 receptors regulate not only basal GMBF, but also acid and Na+ secretion in stomachs. However, the depressive action of 5-HT on GMBF and pepsin secretion is most likely not mediated through 5-HT3 receptors. Ondansetron also modulates the toxicities of ethanol in the stomach and this action is likely to be mediated through the preservation of GMBF.
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PMID:Modulatory role of 5-HT3 receptors in gastric function and ethanol-induced mucosal damage in rat stomachs. 797 27

Ondansetron, a selective 5-HT3 receptor antagonist, has recently been shown, in a dose of 8 mg, to be superior to 1.25 mg droperidol in preventing postoperative vomiting. There are indications that a dose of 4 mg of ondansetron may be just as effective in reducing postoperative nausea and vomiting as a dose of 8 mg. The aim of this study was to evaluate the efficacy and the adverse effects of 4 mg ondansetron in the prevention of postoperative nausea and vomiting compared to droperidol in patients undergoing surgery with inhalation anaesthesia supplemented with alfentanil. METHODS. Following institutional approval, 40 ASA physical status I and II women scheduled for minor gynaecological surgery gave informed consent to participate in this randomized, double-blind comparative study. Five minutes before induction of general anaesthesia, 20 patients received a single intravenous (i.v.) dose of 4 mg of ondansetron and the remaining 20 received 1.25 mg droperidol i.v. Anaesthesia was induced with 2.1-4 mg/kg of thiopental and 0.1 mg of alfentanil i.v. and maintained with 65% nitrous oxide and 1.5%-3% enflurane in oxygen. On pain stimuli another 0.2-0.4 mg of alfentanil was given. Total effective antiemetic response was defined as the absence of nausea and vomiting for 24 h postoperatively. The incidence of nausea, vomiting and the number of patients showing total antiemetic response as well as the incidence of adverse effects were compared with the chi 2 test and P < 0.05 was considered significant. RESULTS. Patients were similar with respect to age, height, body weight and total anaesthetic agents received. Duration of anaesthesia and the time until awakening was not significantly different among groups. Postoperatively 7 out of 20 patients given 4 mg of ondansetron and 3 out of 20 patients with droperidol vomited (n.s.). The incidence of nausea was 11 out of 20 in the ondansetron group, and 4 out of 20 in the droperidol group (P < 0.05). Sixteen patients in the droperidol group and 8 patients in the ondansetron group showed a total effective antiemetic response (P < 0.05). Postoperative sedation and well-being scores did not differ significantly among groups. CONCLUSION. Our results show that for the prevention of postoperative nausea and vomiting 4 mg of Ondansetron was inferior to 1.25 mg of droperidol. The drugs were given intravenously prior to general anaesthesia for minor gynaecological surgery with nitrous oxide and enflurane in oxygen supplemented with small boluses of alfentanil.
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PMID:[Ondansetron as prophylaxis for postoperative nausea and vomiting. A prospective randomized double-blind comparative study with droperidol]. 797 72

The effect of 5HT3 and 5HT4 active compounds on the motivational properties of morphine has been examined in the place conditioning (PC) paradigm using unbiased procedure. Place conditioning with morphine produced significant place preference. Pretreatment with the DAU 6285 (mixed 5HT3 antagonist--5HT4 antagonist) abolished morphine-induced PC. Ondansetron (selective 5HT3 antagonist) attenuated morphine place preference at the dose of 0.1 mg/kg. BIMU 8 (mixed 5HT3 antagonist--5HT4 agonist) failed to modify morphine PC in the 0.001-0.1 mg/kg dose range. While ondansetron given alone failed to produce place conditioning, pairing of BIMU 8 (0.001 mg/kg) induced significant place preference. On the other hand, animals were frequently avoiding compartment paired with the injection of DAU 6285. These findings suggest that 5-hydroxytryptamine by means of 5HT4 receptors mediates appetitive properties of morphine induced-stimuli and suggest that 5HT4 receptor may be involved in the brain reward and reinforcement processes.
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PMID:The effect of drugs interacting with serotonergic 5HT3 and 5HT4 receptors on morphine place conditioning. 801 74

We have investigated the in vivo motor stimulating and gastroprokinetic properties of the azabicycloalkyl benzimidazolone derivative BIMU 1 (3-ethyl-2,3-dihydro-N-(8-methyl-8-azabicyclo[3.2.1]oct-3-yl)-2-oxo-1H- benzimidazole-1-carboxamide hydrochloride) and its binding profile at 5-hydroxytryptamine3 and 5-hydroxytryptamine4 receptors, in an attempt to assess the serotonergic mechanism underlying its prokinetic action. BIMU 1 dose-dependently (0.01-0.3 mg/kg i.v.) increased the motility of a denervated pouch of canine stomach. This excitatory action was sensitive to muscarinic blockade. A similar stimulatory effect was exerted by the benzamidic prokinetic agent cisapride (0.03-0.3 mg/kg i.v.) but not by the 5-HT3 receptor antagonist ondansetron (up to 1 mg/kg i.v.). The significance for propulsive efficacy of the motor stimulating activity of BIMU 1 was evaluated in a model of gastric emptying of liquids in the conscious dog. The emptying rate of a non-caloric liquid meal instilled through a gastric fistula was accelerated by both BIMU 1 (0.01-1 mg/kg i.v. and 0.1-3 mg/kg p.o.) and cisapride (0.03-1 mg/kg i.v. and 0.3-10 mg/kg p.o.). Ondansetron (1 mg/kg i.v.) did not show any effect. The activity of the 5-HT4 receptor antagonist DAU 6285 was evaluated in the gastric emptying model per se and in interaction experiments on the accelerating action of BIMU 1 (0.3 mg/kg i.v.).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Gastroprokinetic properties of the benzimidazolone derivative BIMU 1, an agonist at 5-hydroxytryptamine4 and antagonist at 5-hydroxytryptamine3 receptors. 805 5

Emesis and nausea are common toxicities seen during high-dose interleukin-2 (IL-2) therapy (720,000 IU/kg i.v. every 8 h). A growing list of randomized studies have documented the efficacy of ondansetron, a potent antagonist of the 5-hydroxytryptamine3 receptor, in preventing acute chemotherapy-induced emesis and nausea. However, no study has evaluated the efficacy of ondansetron in preventing IL-2-induced emesis and nausea. This double-blinded, randomized trial was performed to compare the antiemetic and antinausea efficacy of ondansetron with that of droperidol, a butyrophenone, in patients receiving high-dose IL-2 on protocols at the National Cancer Institute. Ondansetron or droperidol was given intravenously, 30 min prior to the first dose of IL-2 and then every 8 h for the duration of IL-2 treatment. No significant differences were seen between the two agents in complete freedom from emesis (p2 = 0.51), level of nausea (p2 = 0.17), antiemetic treatment failure (p2 = 0.89), and time to first emetic episode (p2 = 0.44). Equivalent doses of IL-2 were administered on each arm of the study, with a similar incidence of liver dysfunction (p2 = 0.15) and diarrhea (p2 = 0.64). Finally, there was no significant difference in the response rates to metastatic disease in either arm of the antiemetic study (p2 = 0.67), and these response rates were similar to those in other patients treated under immunotherapy protocols in the Surgery Branch of the National Cancer Institute with high-dose IL-2. We conclude that droperidol is equally effective in preventing emesis and controlling nausea when compared with ondansetron for patients receiving high-dose IL-2.
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PMID:A randomized double-blinded comparison of the antiemetic efficacy of ondansetron and droperidol in patients receiving high-dose interleukin-2. 808 60

Postoperative nausea and vomiting is a major concern for patients undergoing outpatient surgery under general anaesthesia, and may complicate and delay discharge from hospital. This paper evaluates the safety and efficacy of ondansetron, a 5-HT3 receptor antagonist, in the treatment of postoperative nausea and vomiting. One thousand patients in 30 centres in the United States who received general anaesthesia and developed postoperative nausea and vomiting were studied. In a randomised, double-blind, stratified and parallel designed protocol, patients received either ondansetron 1, 4, 8 mg or placebo for nausea or vomiting occurring within 2 h of entry into the Post Anaesthesia Care Unit. Subsequent episodes of vomiting, nausea scores, laboratory and clinical safety data and adverse events were evaluated during the 24-h study period. In a separate study, pharmacokinetic data were compared for intramuscularly and intravenously administered ondansetron. Each dose of ondansetron was significantly better than placebo in reducing nausea from control values during the initial 2-h study period, and in preventing further emesis over 24 h. There were no significant differences in the incidence of adverse events, changes in laboratory values or measures of vital signs in the ondansetron groups compared to the placebo group. Dose comparisons between the three treatment groups showed that ondansetron 4 mg is the optimal dose to treat postoperative nausea and vomiting. Ondansetron is a well tolerated, efficacious antiemetic which has a similar side effect profile to placebo. Intramuscular administration has the same systemic availability as intravenous administration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Single dose intravenous ondansetron for the 24-hour treatment of postoperative nausea and vomiting. 812 59

One-hundred and forty-five chemotherapy patients receiving cisplatin- and non-cisplatin-containing regimens participated in an open evaluation of ondansetron, a 5-HT3 receptor antagonist, in the prophylaxis of acute and delayed nausea and vomiting. The study had two groups of patients, one receiving cisplatin-containing regimens (Group A) and the other, non-cisplatin-containing regimens (Group B). There were 51 patients recruited to Group A. Ondansetron was given to these patients at a dose of 8 mg intravenously 15 min before chemotherapy, followed by an intravenous infusion for 24 h (1 mg/h), or 8 mg intravenously 4 and 8 h after the start of cisplatin, followed by 8 mg orally three times/day for 5 days. Ninety-four patients were recruited to Group B: these patients received ondansetron at a dose of 8 mg intravenously immediately before chemotherapy or 8 mg orally 1-2 h prior to it, and 8 mg orally three times/day for 3-5 days. For acute emesis (first 24 h), complete control was achieved in 79.5% of Group A patients and in 78.1% of Group B. For delayed emesis (days 2-5), 79.7% of Group A patients and 84.6% of Group B were completely protected during the entire study period. Nausea was also well controlled with ondansetron; 83.2% (Group A) and 86.5% (Group B) reported only mild nausea or no nausea at all. Ondansetron was effective in the control of both cisplatin- and non-cisplatin-induced emesis and well tolerated without any serious drug-related adverse events.
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PMID:Ondansetron in the treatment of nausea and vomiting induced by chemotherapy. Portuguese Ondansetron Study Group. 813 12

The potency of Ondansetron (Zofran, Glaxo), a highly specific 5HT3 antagonist in preventing the very unfavorable complication during introducing anesthesia, i.e. a Bezold-Jarisch reflex-like reaction, was studied in a clinical trial. A total of 20 patients (12 males and 8 females aged 19-65 years) admitted for clinical surgical treatment participated in the trial. Zofran (8 mg in 500 ml Ringer solution) was injected intravenously one hour before intubation at a flow rate of 8 ml. min-1. Systolic and diastolic blood pressure, central venous pressure, breathing frequency and minute ventilation, pCO2 and pO2 in venous blood, electrocardiogram monitoring (ECG) and several common features such as spontaneous muscle activity, palpebral reflexes, skin and mucose surfaces were continuously observed. Visual, auscultatory and X-ray control of the lungs was effected. It was found that blockade of 5HT3 receptors prevented the appearance of Bezold-Jarisch reflex-like reaction. The drug could successfully be used in anesthesiological practice.
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PMID:Evaluation of ondansetron as a drug for premedication. 820 75


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