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PubMed1992

Phase III double-blind comparison of intravenous ondansetron and metoclopramide as antiemetic therapy for patients receiving multiple-day cisplatin-based chemotherapy.

BACKGROUND: Ondansetron hydrochloride is a selective serotonin subtype 3 (5HT3) receptor antagonist that has been shown to be an effective antiemetic in patients receiving cisplatin chemotherapy. METHODS: This double-blind study compared the safety and efficacy of intravenous ondansetron with metoclopramide in patients receiving a 4- or 5-day regimen of cisplatin (20-40 mg/m2/day) combination chemotherapy. Forty-five patients were enrolled, and efficacy of the drug therapy could be studied for all 45. Patients were randomly assigned (1:1) to receive three daily intravenous doses of either 0.15 mg/kg ondansetron or 1 mg/kg metoclopramide. All patients were monitored daily for the number of emetic episodes (vomiting or retching), severity of nausea, adverse events, and laboratory safety parameters. RESULTS: Seven (30%) patients who received ondansetron had no emetic episodes throughout the entire study period compared with two (9%) who received metoclopramide (P = 0.077). The greatest difference in antiemetic efficacy was seen on day 1, when 18 (78%) patients who received ondansetron had no emetic episodes compared with 3 (14%) patients who received metoclopramide (P < 0.001). Significantly fewer antiemetic treatment failures (more than five emetic episodes or withdrawal from the study) occurred with patients given ondansetron (9%) than with those given metoclopramide (50%) during the entire study period (P = 0.002). The most commonly reported adverse event associated with ondansetron therapy was headache (controlled with acetaminophen), whereas diarrhea and restlessness were the most commonly reported adverse events associated with metoclopramide therapy. Extrapyramidal symptoms were judged to have occurred in 13 patients who received metoclopramide and 1 patient who received ondansetron. However, the patient who received ondansetron subsequently was judged to have had an anxiety attack. In patients with low or normal baseline transaminase values, a greater percentage who received ondansetron had transient increases as great as twice the upper limit of normal in aspartate transaminase (5% versus 0%) and alanine transaminase (17% versus 6%) than those who received metoclopramide. CONCLUSIONS: Ondansetron is superior to metoclopramide as antiemetic therapy for multiple-day cisplatin-based chemotherapy.

Adolescent↗
PubMed1985

High-dose intravenous metoclopramide and intermittent intramuscular prochlorperazine and diazepam in the management of emesis induced by cis-dichlorodiammineplatinum.

Intravenous metoclopramide and IM prochlorperazine and diazepam were compared in the management of vomiting occurring during treatment with cis-dichlorodiammineplatinum (cis-platinum). A total of 104 cycles in 30 patients were evaluated. Twenty-two patients took part in a cross-over study in which emetic profiles for each patient managed with each anti-emetic schedule were compared. In all, 44 cycles of treatment in 22 patients were evaluated as part of a cross-over study. No significant difference in emetic control was observed between the two anti-emetic regimens. The side-effects observed using IV metoclopramide included extrapyramidal phenomena (19%) and flushing attacks (16%).

Antiemetics↗
PubMed1986

Randomized crossover antiemetic study in cisplatin-treated patients. Comparison between high-dose i.v. metoclopramide and high-dose i.v. dexamethasone.

This prospective, randomized, nonblind study comparing the antiemetic effectiveness of high-dose IV metoclopramide and high-dose IV dexamethasone was performed in 78 advanced cancer patients. Chemotherapeutic treatment consisted in cisplatin at a high-dose (120 mg/m2) (HD-CDDP) and at a low-dose (LD-CDDP), either alone (60 mg/m2) or in combination with other chemotherapeutic agents (50 mg/m2). The evaluation of the effectiveness of antiemetic therapy was based on three parameters: prevention of vomiting ("major protection"), number of emetic episodes, and subjective preference. Out of 78 study patients, 67 were evaluable. Overall, metoclopramide proved to be statistically superior to dexamethasone in preventing vomiting (P less than 0.005), in reducing the median/mean number of emetic episodes (P less than 0.001/0.001), and in subjective preference (P less than 0.01). The results divided between HD-CDDP and LD-CDDP groups were also in favor of metoclopramide for reduction of the median/mean number of emetic episodes (P less than 0.001/0.001 for the HD-CDDP group and P less than 0.001/0.005 for the LD-CDDP group) and in subjective preference (P less than 0.001 and P less than 0.001 for the HD- and LD-CDDP groups, respectively). No statistical differences were noted when LD-CDDP was used in monochemotherapy, whereas when LD-CDDP was used in combination chemotherapy, statistical differences in favor of metoclopramide were noted again for the median/mean number of emetic episodes (P less than 0.01/0.05) and for subjective preference (P less than 0.01), even though the effectiveness of both antiemetic agents was greatly reduced. The evaluation of previously untreated patients reflected the overall results: for the HD-CDDP group all three parameters demonstrated statistical significance in favor of metoclopramide; for the LD-CDDP group, of all three parameters, prevention of vomiting (major protection) was the only one for which there was no significant difference. Mild sedation was the only side effect of metoclopramide. No extrapyramidal reactions were noted during this trial, but concomitant orphenadrine treatment was given. Dexamethasone was always well tolerated. In conclusion, high-dose IV metoclopramide demonstrated its superiority over high-dose IV dexamethasone in all subsets of our population except the LD-CDDP monochemotherapy group, in which the two antiemetics were found to be equivalent in effect.

Adult↗
PubMed1994

Control of emesis by intravenous granisetron in breast cancer patients treated with 5-FU, epirubicin and cyclophosphamide.

Granisetron, a potent and selective 5-hydroxytryptamine receptor (5-HT3) antagonist was reported to be an effective antiemetic agent both in animal studies and in patients given highly emetogenic chemotherapy. A sample of 43 patients with breast cancer was accrued from September to November 1992 in a phase II study to assess the efficacy of granisetron in patients receiving FEC (5-FU, epirubicin, cyclophosphamide). Each patient received 3 mg intravenous granisetron as a single dose just prior to chemotherapy. Oral metoclopromide was prescribed to each patient as a rescue anti-emetic. The emetic episodes and degree of nausea were evaluated on a daily basis. Good control of emesis (0-2 episodes of vomiting) and nausea (mild or no nausea) was in the range 77%-98% and 77%-93% respectively. There was a complete response (no emetic episodes throughout the 6-day period) in 16 patients (37.2%). Onset of emesis tends to occur on day 1 and tend to subside after day 3; 85% of patients had onset of emesis in the first 2 days after chemotherapy. Control of emesis and nausea tends to improve after day 3, which could be the result of the reduced emetogenicity of the combination FEC with time. Altogether, 77% had good control of acute emesis; control of delayed emesis was better with 84% achieving a major response on day 2 after chemotherapy, which improved to more than 90% after day 4. Granisetron was generally tolerated with headache being the most common side-effect followed by constipation and flushing. This study suggests that granisetron is an effective and well-tolerated anti-emetic agent, which deserves randomised trials to elucidate its efficacy further.

Administration, Oral↗
PubMed1989

Ablation of the area postrema and emesis.

The emetic action of dopamine, norepinephrine, epinephrine, nicotine, dimethylphenyl-piperazinium (DMPP), and 4-m-chlorophenylcarbamoyloxy-2-butynyltrimethylammonium (McN-A-343) injected intracerebroventricularly (i.c.v.) to the unanesthetized cat was investigated and compared. ED50 values (mg) were as follows: nicotine, 0.011; epinephrine, 0.047; norepinephrine, 0.57; DMPP, 0.9; dopamine, 1.66; and McN-A-343, 4.42. The most potent was nicotine, whereas the least active McN-A-343. On the other hand, DMPP produced the longest emetic response, about 30 min, while McN-A-343-induced emesis lasted up to 1 min. The ablation of the area postrema abolished the emetic response to i.c.v. dopamine, norepinephrine, epinephrine, nicotine, and DMPP. However, the emetic response to i.c.v. McN-A-343 was significantly reduced in cats with an ablated area postrema. Taken together, the results obtained show that the area postrema is almost always involved in the central regulation of emesis and that the area postrema represents, in most cats, a common site of confluence of different inputs subserving the emesis.

Animals↗
PubMed1997

Prophylactic oral dolasetron mesylate reduces nausea and vomiting after abdominal hysterectomy. The Canadian Dolasetron Study Group.

PURPOSE: The incidence of postoperative nausea and vomiting (PONV) varies from 50% to 75% after gynaecological surgery under general anaesthesia. This study evaluates the dose-response relationships, safety, and efficacy of the new 5-HT3 antagonist, dolasetron mesylate, in the prevention of PONV in women undergoing total abdominal hysterectomy (TAH). METHODS: Three hundred and seventy four women scheduled for TAH under general anaesthesia were studied at 13 Canadian centres. Patients received in a randomized, double-blind manner 25, 50, 100, or 200 mg dolasetron or placebo po one to two hours before induction of anaesthesia. The anesthetic protocol was standardized. Efficacy was evaluated for 24 hr after surgery by comparing the number of emetic episodes, administration of rescue medication, severity of nausea, and patient satisfaction. RESULTS: Analysis of complete response (no emetic episodes and no rescue for 24 hr) revealed a linear dose-response relationship across dolasetron groups (P < 0.002). Dolasetron 100 mg (P < 0.003) and 200 mg (P < 0.01) were superior to placebo. The percentage of patients with no emetic episodes increased from 29.3% (placebo) to 54.1 % (100 mg). Subgroup analysis revealed ASA status (I > II), previous history of PONV, previous history of motion sickness, and total morphine dose (> 55 mg associated with less PONV than < 55 mg) influenced the incidence of emetic symptoms, but did not alter the results of the primary analysis. CONCLUSION: Prophylactic dolasetron (100 mg and 200 mg) reduces the incidence of PONV in patients having total abdominal hysterectomy.

Adolescent↗
PubMed1994

[Ondansetron versus droperidol. Postoperative treatment against nausea and vomiting. Comparison of action, adverse effects and acceptance by gynecologic inpatients].

INTRODUCTION: Ondansetron is more effective than a placebo in treating postoperative nausea and vomiting (PONV), but it has not been proved to be superior to established antiemetics for prophylaxis or therapy. We compared ondansetron vs droperidol for the treatment of PONV. METHODS: Our prospective, randomized double-blind study was performed between 15 October 1992 and July 1993; it included 271 gynaecological ASA I-III inpatients who had been operated on under general anaesthesia with intubation. Patients were excluded if: there was no informed consent; it was an ambulatory or emergency operation; the patient was pregnant or breast feeding; allergies were being treated with antihistamines; drug addiction was present or convulsions or Parkinson's disease; any pre- or intraoperative antiemetic medication had been administered. All patients wishing an antiemetic and/or suffering from at least one emetic episode during the first 24 h postoperatively received either 8 mg ondansetron or 1.25 mg droperidol from identical 4 ml ampoules intravenously. The verbal nausea score (1 = none, 2 = mild, 3 = moderate, 4 = severe) was recorded every 30 min for 4 h, then before and 2 h after each antiemetic dose. All emetic episodes and the interval between administration and effect were also noted. Patients were interviewed 36-48 h postoperatively on subjective effects, side-effects and individual acceptance. After oral premedication with diazepam, anaesthesia was induced with thiopental, in a few cases with etomidate or propofol. Relaxation was achieved with pancuronium or atracurium and, when indicated, with succinylcholine. Muscular relaxation was antagonized with neostigmine and glycopyrrolate. Gastric content was aspirated once after intubation. Anaesthesia was maintained with nitrous oxide/oxygen, enflurane, halothane or isoflurane and fentanyl up to 0.3 mg. Statistical evaluation was performed by the unpaired Student's t-test and the Mann-Whitney U test. Categoric variables were examined by the chi 2 test. Significance was defined as P < 0.05. RESULTS: Of 271 patients, 100 (37%) experienced PONV. The groups were statistically comparable with respect to demographic data, type and duration of operation, emesis record, perioperative uterotonic medication. Twenty patients in the ondansetron group and 27 in the droperidol group received the first antiemetic within 2 h, the other patients up to 17 h after extubation. Nausea scores and emetic episodes were identical before antiemetic medication. The reduction of these parameters after medication was similar. Complete response over 6 h was 60% in the ondansetron and 68% in the droperidol group. In both groups the first medication failed in 4 cases during the initial 2 h. Twenty of the ondansetron and 16 of the droperidol patients needed a second dose; among these 2 and 4, respectively, a third ampoule. No rescue medication was necessary over 24 h and a mean of 1.4 ampoules was administered in both groups. Onset and quality of emetic action were identical in both groups. It was not possible to evaluate 25 interviews due to linguistic or amnestic problems. Multiple side-effects were noted frequently. Injection pain was reported significantly more often in the droperidol, pruritus in the ondansetron group. Ninety-three percent of the ondansetron and 85% of the droperidol patients opted for the same drug for future PONV treatment. CONCLUSIONS: Ondansetron (8 mg) and droperidol (1.25 mg) proved to be equally effective when used as a postoperative antiemetic. Both drugs showed similar side-effects. Due to differences in methods it was difficult to compare our results to those obtained in other studies.

Adult↗
PubMed1995

[Intravenous administration of ondansetron vs. metoclopramide for the prophylaxis of postoperative nausea and vomiting].

This randomized, double-blind, multicentre, parallel-group study compared the efficacy and safety of an intravenous dose of ondansetron 4 mg for the prevention of postoperative nausea and vomiting (PONV) with metoclopramide 10 mg and placebo in patients undergoing major gynaecological surgery. A total of 1044 patients (465 ondansetron, 462 metoclopramide, 117 placebo) received study medication immediately prior to induction of anaesthesia and were included in the analysis of data. The proportion of patients experiencing no emesis and no nausea or provided with rescue antiemetic medication, the number of emetic episodes, and the duration and severity of nausea were recorded during the 24-h period after recovery. Significantly more patients who received ondansetron had no emetic episodes (44%) than those who received metoclopramide (36%, P = 0.049) or placebo (25%, P < 0.001). A higher proportion of patients receiving ondansetron (32%) did not experience nausea (metoclopramide 24%, P = 0.009; placebo 16%, P < 0.001). Significantly fewer patients in the ondansetron group required rescue medication or were withdrawn due to treatment failure (P < 0.05). In the ondansetron group the total number of emetic episodes, the median time to the first emetic episode or treatment failure, and the duration and severity of nausea were reduced significantly compared with metoclopramide or placebo (P < 0.05). The safety profile was similar for each treatment group.

Adult↗
PubMed1992

The effects of 5-HT3 receptor antagonists on cisplatin-induced emesis in the pigeon.

In the present study, the emetic effect of the anticancer drug cisplatin, and the protective effects of 5-HT3 receptor antagonists against cisplatin emesis were investigated in the pigeon. The experimental set-up involved the i.v. administration of drugs and subsequent observation of the percentage of vomiting animals and the number of emetic episodes per vomiting animal. It was observed that cisplatin induced dose-dependent emesis in the pigeon. 5-HT3 receptor antagonists afforded partial protection against cisplatin emesis, although some of them, i.e. indole, indole-like derivatives and zacopride, displayed intrinsic emetic activity. A serotonergic mechanism appears to be involved in both cisplatin- and 5-HT3 receptor antagonist-induced emesis, since pretreatment with an inhibitor of 5-HT synthesis, para-chlorophenylalanine (pCPA), prevented vomiting induced by either cisplatin or 5-HT3 receptor antagonists. It is concluded that the intrinsic emetic effects of 5-HT3 receptor antagonists provide pharmacological evidence of species differences in the properties of 5-HT3 receptors.

Animals↗
PubMed1992

The neuropharmacology of loperamide-induced emesis in the ferret: the role of the area postrema, vagus, opiate and 5-HT3 receptors.

Loperamide, an opiate receptor agonist, commonly used in the treatment of diarrhoea, reliably induced emesis in the ferret, when given subcutaneously. The response latency was short (less than 10 min) and the emesis lasted for approx 70 min. The dose-response curve for the emetic response was "bell-shaped" and all animals responded at 0.5 mg/kg but none at 5 mg/kg (s.c.). The response was unaffected by dopamine D2 receptor antagonism (domperidone 1.0 mg/kg, s.c.) or 5-HT3 receptor antagonism (granisetron or ondansetron 1.0 mg/kg, s.c.). The onset of the response was delayed for about 60 min by naloxone or naloxone methiodide (1.0 mg/kg, s.c.) and abolished by naloxanazine (1.0 mg/kg, s.c.), reported to be relatively selective for mu receptors. The results implicate mu receptors (possibly mu 1) in the induction of emesis by loperamide and provide some support for activation of opiate receptors also having anti-emetic effects, as suggested in previous studies. The emetic response to loperamide was unaffected by abdominal vagotomy but was abolished by ablation of the area postrema, indicating that loperamide-induced emesis may be used as a test for ablation of the area postrema in studies of the emetic mechanism in the ferret.

Animals↗
PubMed1984

Peptide-induced emesis in dogs.

Systemic administration of apomorphine, angiotensin II, neurotensin and leucine-enkephalin induces emesis in dogs in a dose-dependent fashion. Receptors for Leu-enkephalin and angiotensin II but not apomorphine show receptor desensitization, such that a second systemic administration 5 min after the first is ineffective. Domperidone blocked the emetic response to apomorphine but not to Leu-enkephalin or angiotensin II. Naloxone selectively blocked the Leu-enkephalin response, while saralasin blocked responses to both angiotensin II and Leu-enkephalin, but not apomorphine. Chlorpromazine prevented the emetic response to all agents, suggesting a dopamine receptor in the emetic pathway on the brain side of the blood-brain barrier. In dogs with ablation of the area postrema the emetic response to apomorphine and all peptides was prevented.

Angiotensin II↗
PubMed1992

Pharmacologic/pharmacokinetic evaluation of emesis induced by analogs of RSU 1069 and its control by antiemetic agents.

RB 6145, the ring-opened analog of RSU 1069, and PD 130908, the desoxy ring-opened analog of RSU 1069, were compared to RSU 1069 for their emetic potential in dogs. When RB 6145 and PD 130908 were administered intravenously at doses ranging from 20% to 50% of the mouse equivalent maximum tolerated dose (MTD), both analogs were less emetic than RSU 1069 on a molar basis. Furthermore, the 5HT3 antagonist ondansetron prevented emesis at doses as high as 75% of the MTD. The reactivity, and hence the emetic liability of these compounds, is thought to be mediated by formation of the corresponding aziridine intermediate. In mouse plasma, both analogs rapidly converted to two products, the reactive aziridine and a stable oxiazolidinone species formed upon reaction with bicarbonate in the blood. A positive correlation exists between the amounts of aziridine formed by these analogs and their emetic potential.

Animals↗
PubMed1992

A dual effect of some 5-HT3 receptor antagonists on cisplatin-induced emesis in the pigeon.

In the present study, the emetic effect of the anticancer drug cisplatin, and protective effects of 5-HT3 receptor antagonists against cisplatin emesis were investigated in the pigeon. The experimental setting involved the i.v. administration of drugs and subsequent observation of the percentage of vomiting animals and number of emetic episodes per vomiting animal over a period of 5 h. In some experiments, the 5-HT and 5-HIAA content in tissues was estimated by the HPLC technique. It was observed that cisplatin (2.5-10 mg/kg) is able to induce dose-dependent emesis in the pigeon. 5-HT3 receptor antagonists (500 micrograms/kg) afford partial protection against cisplatin emesis, although some of them, i.e. indolic derivatives and zacopride, display intrinsic emetic activity at doses of 50-500 micrograms/kg. A serotonergic mechanism appears to be involved in both cisplatin- and 5-HT3 receptor antagonist-induced emesis, since pretreatment with an inhibitor of 5-HT synthesis, para-chlorophenylalanine (300 mg/kg x 3 days), is able to hamper vomiting induced by either cisplatin or 5-HT3 receptor antagonists. It is concluded that the intrinsic emetic effects of 5-HT3 receptor antagonists in the pigeon provide pharmacological evidence of species differences in the properties of 5 HT3 receptors.

Animals↗
PubMed2006

Altered feeding behaviour induced by long-term cisplatin in rats.

In animals without the emetic reflex, several emetogenic stimuli induce pica, an altered feeding behaviour consisting of the ingestion of non-nutritive substances. The development of pica in response to an emetogenic stimulus has been proposed to be useful as an indirect marker of nausea in the rat. In fact, like nausea and emesis in humans, it is accompanied by serotonin release from the enterochromaffin cells, increased c-fos labelling in the area postrema and the nucleus tractus solitarius, and a delay in gastric emptying. Furthermore, pica, measured as kaolin intake, is reduced by anti-emetic drugs. Pica has been demonstrated after single doses of cisplatin, the most emetogenic chemotherapeutic drug. However, cisplatin, as other antineoplastic drugs, is generally given in cycles, where conventional anti-emetics tend to lose efficiency. The aim of this work was to evaluate the pica induced by long-term treatment with cisplatin. Saline or cisplatin was administered once a week for 5 consecutive weeks, and temperature, body weight, food ingestion and kaolin intake were measured on a daily basis. The influence of isolation (pica is necessarily studied in isolated animals) and exposure to kaolin (basal kaolin intake could modify pica itself and other parameters) on temperature, body weight and daily food ingestion was negligible in saline-treated rats. Cisplatin administered at 3 mg/kg/week was too toxic: it produced hypothermia, weight drop and anorexia in both grouped and isolated rats, and 50% mortality in isolated animals. Toxicity associated with cisplatin administered at 1 mg/kg/week was acceptable, with a slower rate of weight gain being the major effect. In these rats, each cisplatin injection produced both acute anorexia and rebound hyperphagic responses. In addition, each administration induced both acute pica and an increase in basal kaolin intake, resembling the development of nausea in humans. This model could be useful for studying both the mechanisms leading to nausea associated with a long-term antineoplastic treatment and the efficiency of new anti-emetic drugs.

Animals↗
PubMed2004

Effect of a selective and potent central nervous system penetrant, neurokinin-3 receptor antagonist (SB-222200), on cisplatin-induced emesis in the ferret.

The anti-emetic activity of selective NK-1 receptor antagonism is well established. However, little is known of the possibility that other NK receptors might also be involved in the emetic reflex. Given the reported location of NK-3 receptors within the rat brainstem vagal motor and sensory nuclei, we investigated the ability of SB-222200, a brain-penetrant NK-3 receptor antagonist, to interfere with emesis evoked in ferrets by the emetogenic cytotoxic agent cisplatin. In contrast to control anti-emetic experiments using the 5-HT3 receptor antagonist ondansetron, SB-222200 was found to have no effects on cisplatin-induced vomiting or on the associated reductions in feeding and drinking behaviors at any dose tested. We suggest that if NK-3 receptors are involved in the mechanisms of cisplatin-induced nausea and vomiting, they play only a minor role, relative to the major anti-emetic activity exhibited by 5-HT3 or NK-1 receptor antagonism.

Animals↗
PubMed2000

Cisplatin-induced emesis in the cat: effect of granisetron and dexamethasone.

The emetic action of cisplatin was investigated in the cat using a closed circuit video recording system. In initial investigations, cisplatin 3 and 5 mg/kg, i.v. induced emesis over a 2-day period following a latency of 17.6+/-9.6 and 15.6+/-7.8 h, respectively. The anti-emetic efficacy of granisetron and dexamethasone was investigated in the cisplatin 5 mg/kg, i.v.-induced emesis model. In these experiments, cisplatin induced 47.0+/-14.0 and 20.0+/-9.0 retches+vomits on days 1 and 2, respectively, following a latency of 2.4+/-0.4 h. Granisetron (1 mg/kg, i.m.) administered three times per day reduced significantly the retching+vomiting response induced by cisplatin on days 1 and 2 by 100.0% (P<0.05) and 75.0% (P<0.05), respectively; dexamethasone (0.01-1 mg/kg, i.m.) administered three times per day reduced significantly the retching+vomiting response by 68.8-100.0% (P<0.05) and 33.3-100.0% (P<0.05) on days 1 and 2, respectively. The emetic action of cisplatin 7.5 mg/kg, i.v. was also investigated. This dose of cisplatin-induced emesis following a latency of 1.2+/-0.2 h and comprised 119.0+/-20.8 retches+vomits over a 24-h period. Granisetron and dexamethasone antagonized the emesis occurring in the first 3-h period (P<0.05) but were less effective to antagonize the subsequent emetic response (P0.05). The pharmacological sensitivity of low dose cisplatin-induced emesis in the cat is variable but unique and not representative of the clinical situation.

Animals↗
PubMed2003

Antiemetic effect of a tachykinin NK1 receptor antagonist GR205171 on cisplatin-induced early and delayed emesis in the pigeon.

Cisplatin (4 mg/kg, i.v.) induced both early emesis, which appears within the first 8-h period, and delayed emesis, which appears between 8 and 48 h after its administration to pigeons. GR205171 ([(2S-cis)-N-((2-methoxy-5(5-(trifluoromethyl)-1H-tetrazol-1-yl)-phenyl) methyl)-2-phenyl-3-piperidinamine dihydrochloride]) administered intramuscularly (1-10 mg/kg) reduced significantly the number of emetic response to cisplatin: this reduction was 60-81% (P < 0.05) for early emesis and 48-64% (P < 0.05) for the delayed response. Intracerebroventricularly administered GR205171 (30 microg/kg) also reduced the number of emetic responses: 53% (P < 0.05) in early emesis and 88% (P < 0.05) in the delayed response. However, the latency time to the first emesis was not affected by GR205171. Direct injection of cisplatin (10 microg/kg) into the fourth ventricle produced emesis, which was reduced by GR205171 administered via the peripheral or central route. Substance P-immunoreactive fibres were distributed throughout the dorsal vagal complex. These results suggest that the antiemetic effect of GR205171 on both emetic responses to cisplatin acts on a central site, and that the onset of the emetic response may be mediated partly via GR205171-insensitive mechanisms.

Animals↗
PubMed1997

Effects of a 5-HT1A receptor agonist on acute and delayed cyclophosphamide-induced vomiting.

LY228729 [(-)-4(dipropylamino)-1,3,4,5-tetrahydrobenz-[c,d]indole-6-carboxa mide]], an agonist at the 5-HT1A subtype of 5-HT receptor, was studied as an antiemetic in pigeons dosed with a highly emetic oncolytic agent, cyclophosphamide. An intramuscular injection of 0.32 mg/kg of LY228729 administered 15 min prior to the intravenous injection of 200 mg/kg of cyclophosphamide totally prevented the acute emetic response induced by cyclophosphamide. When used as a rescue therapy in a separate group of pigeons, LY228729 (0.32 mg/kg, i.m.) prevented further emetic episodes when it was administered after vomiting had already been induced by cyclophosphamide. Injections of LY228729 given at intervals over the next 2 d also attenuated the delayed emetic response induced by cyclophosphamide. LY228729 appears to be a broad spectrum antiemetic agent that is effective against the anticipatory, the acute and the delayed stages of emesis induced by oncolytic agents.

Animals↗