Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042963 (vomiting)
 31,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Selective 5-HT3 antagonists have proven to be safe and effective for the prevention of chemotherapy-induced nausea and vomiting. Dolasetron is a new highly selective addition to this class of antiemetics that has been shown to have significant antiemetic activity in patients receiving cisplatin-containing regimens. This pilot study was designed to evaluate the antiemetic efficacy of dolasetron in cancer patients receiving doxorubicin and/or cyclophosphamide. This study used an open-label, non-randomized design to evaluate the efficacy and safety of intravenous dolasetron in the prevention of emesis in patients receiving doxorubicin (25-75 mg/m2) and/or cyclophosphamide (400-1200 mg/m2). Sixty-nine patients received a single, intravenous dose of dolasetron over 15-20 min beginning 30 min prior to the start of chemotherapy. Dose levels of dolasetron studied were: 0.3, 0.6, 1.2, 1.8 and 2.4 mg/kg. Patients were monitored for emesis, nausea and adverse events for 24h after the start of chemotherapy. Overall, 61% of patients experienced complete control of emesis. No significant trend towards increased antiemetic efficacy (P = 0.076) or nausea control with increasing dolasetron dose was noted, although the power to detect significant differences was limited by the small number of patients on the 0.3-mg/kg and 2.4-mg/kg dose levels. Age, gender, and type of chemotherapy were significant predictors of complete antiemetic control. Adverse events were generally mild and included headache, chills, lightheadedness, fever, diarrhea, dizziness, and asymptomatic prolongation of ECG intervals. Intravenous dolasetron is safe and effective in the prevention of emesis induced by doxorubicin and/or cyclophosphamide.
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PMID:Dose-ranging evaluation of the antiemetic efficacy of intravenous dolasetron in patients receiving chemotherapy with doxorubicin or cyclophosphamide. 867 51

Dolasetron mesilate [(2 alpha, 6 alpha, 8 alpha, 9a beta)-octahydro-3-oxo-2,6-methano-2H-quinolizin-8-yl-1H-indole-3-c arboxylate monomethane-sulfonate], is a 5-HT3 receptor antagonist, which is in development for the treatment of chemotherapy-induced emesis. The compound is rapidly reduced by carbonyl reductase to form its major pharmacologically active metabolite reduced dolasetron (red-dolasetron), which us further metabolized by cytochrome P450 (CYP450). Studies were conducted, using human liver microsomes, to characterize the CYP450 enzymes responsible for the in vitro metabolism of red-dolasetron. Red-dolasetron underwent oxidation of the indole aromatic ring at positions 5, 6, and 7, and also N-oxidation. Enzyme-selective inhibition and correlation studies showed that hydroxylation of red-dolasetron was CYP2D6-dependent, and N-oxidation was conducted by CYP3A4. The rate of formation of 6-hydroxy red-dolasetron was significantly correlated with that of 5-hydroxy red-dolasetron, which further suggested that these metabolites were formed by the same CYP450 enzyme(s). Inhibition studies also demonstrated that 6-hydroxylation was, to a lesser extent, CYP3A4-dependent. This was confirmed by correlation experiments, wherein formation of this metabolite was significantly correlated with that of N-oxide formation, in quinidine-inhibited microsomes. Results were compared with those obtained with two other indole-containing 5-HT3 receptor antagonists: tropisetron and ondansetron. Tropisetron hydroxylation was CYP2D6-dependent, whereas that of ondansetron was both CYP2D6- and CYP2E1-dependent. Results were further confirmed, when compounds were incubated with microsomes containing recombinant human liver CYP2D6, CYP3A4, and CYP2E1. Red-dolasetron was a competitive inhibitor of CYP2D6, with an IC50 value of 70 microM, which is 2 orders of magnitude above maximum plasma concentrations found in humans. The implications of these in vitro results to the in vivo metabolism of these compounds in humans and their potential pharmacokinetic consequences is discussed.
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PMID:Characterization of the cytochrome P450 enzymes involved in the in vitro metabolism of dolasetron. Comparison with other indole-containing 5-HT3 antagonists. 872 43

Dolasetron mesilate (Anzemet) ((2 alpha, 6 alpha, 8 alpha, 9a beta)-octahydro-3-oxo-2,6-methano-2H-quinolizin-8-yl-1 H-indole-3-carboxylate monomethane-sulfonate) is a 5-HT3 receptor antagonist, which is in development for the treatment of chemotherapy-induced emesis. The ketone moiety of dolasetron is rapidly reduced by carbonyl reductase to form an alcohol, reduced dolasetron (red-dolasetron), which is the major pharmacologically active metabolite in humans. The pharmacokinetics of dolasetron and red-dolasetron were compared in dog, after single intravenous (i.v.) (2 mg/kg) and oral (p.o.) (5 mg/kg) administration of [14C]dolasetron or [14C]red-dolasetron. Pharmacokinetic parameters of dolasetron showed a terminal elimination half-life (t1/2) of 0.1 h, total body plasma clearance (Cltot) of around 109 mL/min/kg, apparent volume of distribution (aVd beta) of 0.83 L/kg, and bioavailability (F) of 7%. Pharmacokinetic parameters of red-dolasetron, calculated after dolasetron or red-dolasetron administration, were very similar. The t1/2 was around 4.0 h, Cltot 25 mL/min/kg, aVd beta 8.5 L/kg, and F around 100%. The apparent first-order formation rate constant (ki) of red-dolasetron was 7 h-1, which was similar to the first-order elimination rate constant (kel) of dolasetron. Cmax of red-dolasetron was similar, after po administration of either compound, but the median Tmax was 0.33 h after dolasetron, compared with 1.5 h after red-dolasetron. The first-order absorption rate constants (ka) of dolasetron and red-dolasetron were 14 h-1 and 2 h-1, respectively. Dolasetron transport across Caco-2 cell monolayers was also higher than that of red-dolasetron. Thus dolasetron was more quickly absorbed than red-dolasetron, and its administration led to the more rapid appearance of red-dolasetron in plasma. There appears to be no advantage in the direct administration of the metabolite, especially as in humans oral administration of dolasetron, 30 min before chemotherapy, has been shown to be effective in preventing emesis.
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PMID:Comparison of the pharmacokinetics of dolasetron and its major active metabolite, reduced dolasetron, in dog. 881 90

The aim of this work was to measure the safety and efficacy of single i.v. doses of dolasetron mesilate for the control of emesis caused by single high-dose (at least 6 Gy) radiotherapy to the upper abdomen. The double-blind, placebo-controlled, multicenter study stratified patients on the basis of being naive or nonnaive to radiotherapy. Patients with or without a history of previous chemotherapy were enrolled. Patients were randomized to receive placebo or 0.3, 0.6, or 1.2 mg/kg dolasetron mesilate 30 min before radiotherapy, then monitored for 24 h. Antiemetic efficacy was assessed from the time to the first emetic episode or rescue, from whether there was a complete response (0 emetic episodes /no rescue medication) or a complete-plus-major response (0-2 emetic episodes/no rescue medication), from the severity of nausea (rated by patients and the investigator), and from the investigator's assessment of efficacy. Fifty patients completed the study (owing to changing medical practice, enrollment objectives were not met; consequently, no significant linear dose trend was expected). Pooled dolasetron was superior to the placebo in its effect on the time to first emesis or rescue in radiotherapy-nonnaive patients (P = 0.015). Dolasetron was statistically superior to the placebo in the overall population on the basis of a complete plus major response: 54%, 100%, 93%, and 83% for the placebo and 0.3-, 0.6-, and 1.2-mg/kg doses respectively (P = 0.002). The low response in the highest dose group may be due to an imbalance in the number of chemotherapy-nonnaive patients in that group. Dolasetron was superior to the placebo on the basis of nausea assessed by the investigator (P = 0.024) and administration of rescue medication (P = 0.006). Complete response at the 0.3-mg/ kg dose was superior to results with the placebo (P = 0.050). Treatment-related adverse events were rare, mild to moderate in intensity, and evenly distributed across the four groups. Overall, dolasetron mesilate was effective and well-tolerated in the control of single, high-dose radiotherapy-induced emesis.
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PMID:A double-blind, placebo-controlled trial of i.v. dolasetron mesilate in the prevention of radiotherapy-induced nausea and vomiting in cancer patients. 888 32

The potent serotonin receptor (5-HT3) antagonists are new highly selective agents for the prevention and control of chemotherapy-induced nausea and vomiting that have been shown to be comparable to or more effective than traditional metoclopramide regimens. This study was designed to compare the antiemetic efficacy of dolasetron and metoclopramide in chemotherapy-naive and non-naive cancer patients receiving high-dose cisplatin-containing chemotherapy. This multicentre, double-blind, randomized trial compared the efficacy and safety of single i.v. doses of dolasetron mesilate salt (1.2 or 1.8 mg/kg) and metoclopramide (7 mg/kg) in 226 patients for the prevention of acute emesis and nausea associated with the administration of high-dose (> or = 80 mg/m2) cisplatin. Efficacy and safety were evaluated for 24 h. Complete responses were achieved by 57%, 48%, and 35% of patients given dolasetron mesilate 1.8 mg/kg (P = 0.0009 vs metoclopramide), dolasetron mesilate 1.2 mg/kg (P = 0.0058 vs metoclopramide), and metoclopramide, respectively. Overall, dolasetron was significantly more effective than metoclopramide for time to first emetic episode, nausea, patient satisfaction, and investigator global assessment of efficacy. Males, chemotherapy-naive patients, and alcoholics had higher response rates. Dolasetron was well tolerated, with mild-to-moderate headache most commonly reported. Twelve percent of patients receiving metoclopramide reported extrapyramidal symptoms compared with 0% of patients receiving dolasetron. In conclusion, dolasetron mesilate was effective for the prevention of CINV with high-dose cisplatin. Single i.v. doses of dolasetron mesilate were more effective than 7 mg/kg metoclopramide in preventing nausea and vomiting induced by highly emetogenic cisplatin-containing chemotherapy. In addition, 1.8 mg/kg dolasetron mesilate consistently produced the highest response rates and appears to be the most effective dose for further clinical development.
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PMID:A double-blind, multicentre comparison of intravenous dolasetron mesilate and metoclopramide in the prevention of nausea and vomiting in cancer patients receiving high-dose cisplatin chemotherapy. 901 Sep 86

Dolasetron (dolasetron mesilate) is a pseudopelletierine-derived 5-HT3 antagonist which has recently become available for clinical use. It is rapidly converted in vivo to its active major metabolite, hydrodolasetron, which appears to be largely responsible for its pharmacological activity. In clinical trials, single intravenous or oral doses of dolasetron were effective in preventing acute chemotherapy-induced nausea and vomiting (CINV). Intravenous doses of 1.8 mg/kg achieved complete suppression of vomiting in approximately 50% of patients receiving highly emetogenic cisplatin-containing chemotherapy and in approximately 60 to 80% of patients receiving moderately emetogenic chemotherapy. In the latter setting, oral doses of 200 mg achieved similar response rates. In comparative studies, intravenous dolasetron 1.8 mg/kg was as effective as intravenous granisetron 3 mg or ondansetron 32 mg after highly emetogenic chemotherapy, and oral dolasetron 200 mg was equivalent to multiple oral doses of ondansetron (3 or 4 doses of 8 mg) after moderately emetogenic chemotherapy. Dolasetron 1.8 mg/kg was superior to metoclopramide in preventing emesis induced by high dose cisplatin or by moderately emetogenic chemotherapy in high risk subgroups. Dolasetron has also shown efficacy in preventing radiotherapy-induced nausea and vomiting (RINV) in preliminary studies. Single intravenous or oral dolasetron doses ranging from 12.5 to 100 mg and 25 to 200 mg, respectively, were significantly more effective than placebo in preventing postoperative nausea and vomiting (PONV) in female surgical patients. A 50 mg intravenous dose was as effective in preventing PONV as ondansetron 4 mg in a mixed-gender group. Intravenously administered dolasetron was also effective in treating established PONV, although complete suppression of vomiting was achieved in < 40% of patients. Dolasetron has a tolerability profile characteristic of this class of compounds, with headache, dizziness and diarrhoea being the most commonly occurring adverse events in clinical trials. Diarrhoea is not thought to be related to dolasetron administration, being experienced mostly by patients receiving chemotherapy. Dolasetron and other 5-HT3 receptor antagonists have been associated with minor changes in ECG intervals, but these generally do not appear to be clinically important. Thus, available evidence suggests that dolasetron will provide an alternative to other 5-HT3 receptor antagonists for the management of CINV and PONV. Further studies are required to determine whether it offers any advantages over other agents in these settings and to determine the optimum dosage for preventing RINV.
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PMID:Dolasetron. A review of its pharmacology and therapeutic potential in the management of nausea and vomiting induced by chemotherapy, radiotherapy or surgery. 925 83

Dolasetron mesilate is a selective 5-HT3 receptor antagonist that prevents chemotherapy-induced and postoperative nausea and vomiting. For the majority of patients in intravenous dolasetron trials for chemotherapy-induced nausea and vomiting, dosing has been based on body weight (mg/kg). The approved weight-based dose is 1.8 mg/kg based on results of controlled clinical trials. However, trials of dolasetron evaluating oral doses for prevention of chemotherapy-induced emesis, and intravenous doses for prevention and treatment of postoperative emesis have used a fixed milligram dose. To identify an appropriate intravenous fixed milligram dose for the prevention of chemotherapy-induced nausea and vomiting, this analysis was performed to derive efficacy results for fixed milligram doses from pooled results obtained with dosing based on body weight. Intravenous dolasetron doses for 1,598 patients treated on a mg/kg basis (0.3, 0.6, 1.2, 1.8, 2.4, 3.0 and 5.0 mg/kg) in 14 clinical trials were converted to fixed milligram doses based on weight. Fixed-dose groups were established at doses of 50, 75, 100, 125, 150, and 200 mg. Doses less than or equal to the midpoint between two dose groups were included in the lower dose group. Pooled results showed that the 100 mg intravenous dolasetron dose group (who received actual doses of 88-112 mg) produced the highest rate (53%) of complete response (0 emetic episodes and no rescue medication in the 24-h period following initiation of chemotherapy).
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PMID:Rationale for the use of a single fixed intravenous dolasetron dose for the prevention of cisplatin-induced nausea and vomiting. Pooled analysis of 14 clinical trials. 977 66

Fractionated cisplatin-containing regimens are routinely used for chemotherapy in certain types of cancer. Dolasetron has been shown to be effective in preventing acute emesis related to high-dose cisplatin chemotherapy over 24 h; its effectiveness has not been evaluated in fractionated cisplatin-containing chemotherapy. This trial was designed to assess the efficacy of dolasetron alone or dolasetron plus dexamethasone in preventing nausea and vomiting related to fractionated cisplatin chemotherapy. The patients were 210 cancer in-patients, who were randomised to receive 100 mg dolasetron i.v. or 100 mg dolasetron i.v. plus 20 mg dexamethasone before chemotherapy primarily with cisplatin (15-50 mg/m2) infused over < or =4 h for at least 2 but not more than 5 consecutive days. Dolasetron was administered to all patients 30 min before cisplatin. Dexamethasone was administered in double-blind fashion 5 min before cisplatin. Efficacy was measured at hour 24 of each study day using complete response (no vomiting and no rescue medication) and maximum severity of nausea, self-assessed by patients using a 100mm visual analogue scale. Most (198) of the patients completed the study and were evaluable. Overall complete response rates were significantly higher in the dolasetron plus dexamethasone group than in the dolasetron only group (72.9% vs. 40.8%, respectively; P<0.0001). Complete response rates on each study day were also significantly higher with dolasetron plus dexamethasone than with dolasetron alone (P<0.029), with an attenuated efficacy in the delayed phase in both groups. Chi-square test and logistic regression applied to daily response rates indicated a significant influence of treatment (day 1: P = 0.0002, day 2: P<0.0001, day 3: P = 0.0007, day 4: P = 0.0007, day 5: P = 0.029). Treatment and duration of chemotherapy exerted the only statistically significant subgroup effects on complete response (P<0.0001). Both treatments were administered safely. As seen with other 5-HT3 receptor antagonist antiemetics, the addition of dexamethasone to dolasetron significantly increases effectiveness in preventing nausea and vomiting related to fractionated cisplatin chemotherapy. Both dolasetron and dolasetron plus dexamethasone were well tolerated.
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PMID:A double-blind, randomised, parallel study comparing intravenous dolasetron plus dexamethasone and intravenous dolasetron alone for the management of fractionated cisplatin-related nausea and vomiting. 1065 Aug 98

In a multicentre, randomized, double-blind, placebo-controlled dose-ranging study, 1030 patients undergoing outpatient surgery with general anaesthesia received i.v. dolasetron mesylate (12.5, 25, 50, or 100 mg) or placebo. The principal outcome measure was the proportion of patients who were free of emesis or rescue medication for the 24-h period after the study drug was given; the subsidiary outcome measure was survival time without rescue medication. Effects on nausea were quantified using a visual analogue scale. Compared with placebo, a complete response was significantly higher when all four dolasetron doses were combined (49% vs. 58%, P =0.025). In females, dolasetron, 12.5-mg, dolasetron provided maximum clinical benefit (effectiveness compared with adverse events), with no additional benefit in complete response rates or nausea visual analogue scale scores at higher doses. No significant differences were observed in complete response for any dolasetron dose in males compared with placebo. The majority of adverse events reported were mild or moderate. Dolasetron provided well-tolerated, safe, and effective prophylaxis for post-operative nausea and vomiting with maximum effectiveness observed at a dose of 12.5 mg.
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PMID:Dolasetron for the prevention of postoperative nausea and vomiting following outpatient surgery with general anaesthesia: a randomized, placebo-controlled study. The Dolasetron PONV Prevention Study Group. 1075 40

BACKGROUND: The relative efficacy of antiemetics for the treatment of postoperative nausea and vomiting (PONV) is poorly understood. METHODS: Systematic search (MEDLINE, Embase, Cochrane Library, bibliographies, any language, to 8.2000) for randomised comparisons of antiemetics with any comparator for the treatment of established PONV. Dichotomous data on prevention of further nausea and vomiting, and on side effects were combined using a fixed effect model. RESULTS: In seven trials (1,267 patients), 11 different antiemetics were tested without placebos; these data were not further analysed. Eighteen trials (3,809) had placebo controls. Dolasetron 12.5-100 mg, granisetron 0.1-3 mg, tropisetron 0.5-5 mg, and ondansetron 1-8 mg prevented further vomiting with little evidence of dose-responsiveness; with all regimens, absolute risk reductions compared with placebo were 20%-30%. The anti-nausea effect was less pronounced. Headache was dose-dependent. Results on propofol were contradictory. The NK1 antagonist GR205171, isopropyl alcohol vapor, metoclopramide, domperidone, and midazolam were tested in one trial each with a limited number of patients. CONCLUSIONS: Of 100 vomiting surgical patients receiving a 5-HT3 receptor antagonist, 20 to 30 will stop vomiting who would not have done so had they received a placebo; less will profit from the anti-nausea effect. There is a lack of evidence for a clinically relevant dose-response; minimal effective doses may be used. There is a discrepancy between the plethora of trials on prevention of PONV and the paucity of trials on treatment of established symptoms. Valid data on the therapeutic efficacy of classic antiemetics, which have been used for decades, are needed.
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PMID:Treatment of established postoperative nausea and vomiting: a quantitative systematic review. 1173 64


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