itasetron and Vomiting

Nausea and vomiting induced by chemotherapy are a major cause of distress to patients and reduce compliance with potentially beneficial treatment. Itasetron hydrochloride is a new 5-hydroxytryptamine3 (5-HT3) antagonist with potent antiemetic properties. It is more potent than ondansetron in animal models and in early clinical studies it demonstrates a long half-life and does not undergo hepatic biotransformation before elimination. The aim of this open, uncontrolled study was to establish the effective dose range of itasetron hydrochloride given intravenously (i.v.) to patients due to receive high-dose cisplatin chemotherapy (50-120 mg/m2) for the first time. Thirty-nine patients were enrolled in the trial and received a single i.v. infusion of itasetron hydrochloride at a dose of 17-280 microg/kg body weight before commencing the cisplatin infusion (median dose 90-110 mg/m2). Antiemetic protection was demonstrated by doses in the range of 35-280 microg/kg. The 17 microg/kg dose was not effective. Treatment failure (>5 emetic episodes/24 hours) was reported in only six (16%) of the 38 evaluable patients over all treatment groups. Adverse events were generally mild or moderate and of a similar type and incidence to those of current 5-HT3 antagonists. Physicians' and patients' assessments of efficacy and tolerability of itasetron hydrochloride were similar, the majority rating the treatment as 'good' or 'very good'. In conclusion, itasetron hydrochloride is effective in the dose range 35-280 microg/kg in preventing cisplatin-induced emesis. Taken together with results from a larger dose-finding study, a dose corresponding to 35 microg/kg (equivalent to 2.5 mg itasetron, calculated as free base) has been pursued in Phase III studies with the i.v. formulation.

Topics: Acute Disease; Adult; Aged; Antiemetics; Antineoplastic Agents; Benzimidazoles; Bridged Bicyclo Compounds, Heterocyclic; Cisplatin; Dose-Response Relationship, Drug; Female; Humans; Injections, Intravenous; Male; Middle Aged; Severity of Illness Index; Treatment Outcome; Vomiting

Itasetron hydrochloride is a new 5-hydroxytryptamine3 (5-HT3) antagonist. Experimental investigations show that orally it is rapidly absorbed (about 90 min), is highly bioavailable (greater than 90%), has a long half-life (about 12 h) and is more potent (about 10 times) in animal models than ondansetron, currently standard therapy for the prophylactic control of chemotherapy induced nausea and vomiting. This paper describes the results of a study designed to assess the efficacy and tolerability of five (0.5, 1, 2, 4 and 8 mg) twice-daily doses of itasetron hydrochloride, in comparison with 8 mg b.i.d. ondansetron. Assessments were made in patients (n = 104) with histologically confirmed cancer (excluding head and neck tumors) and about to receive their first course of moderately emetogenic chemotherapy. Itasetron hydrochloride demonstrated comparable efficacy to ondansetron; no statistically significant between-group differences were observed in the primary (complete response rate) or secondary (nausea and delayed emesis) efficacy criteria. Adverse events were similar in type and incidence across all treatment groups, and were those expected for this therapeutic class. The tolerability of itasetron hydrochloride was assessed as 'very good' or 'rather good' by 81% of patients and 89% of physicians. In conclusion, itasetron hydrochloride is effective and well tolerated in patients receiving moderately emetogenic chemotherapy. Oral doses of 1 mg b.i.d. or above will be used in further clinical studies.

Topics: Adult; Aged; Antiemetics; Antineoplastic Agents; Benzimidazoles; Biological Availability; Bridged Bicyclo Compounds, Heterocyclic; Double-Blind Method; Humans; Middle Aged; Neoplasms; Ondansetron; Vomiting

Topics: Animals; Antiemetics; Antineoplastic Agents; Benzimidazoles; Bridged Bicyclo Compounds, Heterocyclic; Controlled Clinical Trials as Topic; Humans; Multicenter Studies as Topic; Receptors, Serotonin; Receptors, Serotonin, 5-HT3; Serotonin Antagonists; Vomiting

The antiemetic activity of DAU 6215, a novel antagonist of 5-HT3 receptors, was investigated in animal models of cytotoxic treatment-evoked emesis and compared with the antiemetic activity of ondansetron and metoclopramide. In dogs, vomiting was induced by i.v. cisplatin; in ferrets, the emetic response was elicited by i.v. doxorubicin or X-ray exposure. Pretreatment with 0.1-1 mg/kg DAU 6215 given i.v. or p.o. prevented the vomiting response to the different emetic agents. In the dog, the antiemetic potency of metoclopramide was 30 times lower than that of DAU 6215. Ondansetron was less potent than DAU 6215 against cisplatin and doxorubicin but was equally effective in the radiotherapy protocol. In this model, lengthening of the pretreatment time to 2 h did not affect the antiemetic efficacy of DAU 6215, whereas it decreased that of ondansetron. The results demonstrate that DAU 6215 is a highly effective and long-lasting inhibitor of cytotoxic treatment-induced emesis in different animal species.

Topics: Animals; Antiemetics; Benzimidazoles; Bridged Bicyclo Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cisplatin; Disease Models, Animal; Dogs; Dose-Response Relationship, Drug; Doxorubicin; Drug Evaluation, Preclinical; Female; Ferrets; Imidazoles; Male; Metoclopramide; Neoplasms, Experimental; Ondansetron; Serotonin Antagonists; Time Factors; Vomiting