bemesetron and Vomiting

Topics: Afferent Pathways; Animals; Antiemetics; Antineoplastic Agents; Brain Stem; Chemoreceptor Cells; Ferrets; Humans; Ion Channels; Ondansetron; Postoperative Complications; Radiotherapy; Receptors, Serotonin; Reflex; Serotonin; Serotonin Antagonists; Solitary Nucleus; Tropanes; Vagus Nerve; Vestibule, Labyrinth; Vomiting

This pilot randomized study compared MDL 72,222, a highly selective 5-HT3 receptor antagonist, with a high-dose metoclopramide regimen (HDM) for chemotherapy-induced nausea and vomiting. MDL 72,222 was given in 20 mg intravenous doses 30 minutes before chemotherapy, as well as 2, 6, and 12 hours after chemotherapy infusion. The HDM was composed of diphenhydramine 50 mg i.v., metoclopramide 2 mg/kg i.v., and lorazepam 0.04 mg/kg i.v. administered 30 minutes before chemotherapy and 2, 4, 6, and 8 hours after chemotherapy. Patients were randomized to either MDL 72,222 (n = 12) or the HDM (n = 12) and were matched for age, weight, Karnofsky performance status, and chemotherapy. More patients in the MDL 72,222 group had received prior cisplatin. The MDL 72,222 group and the HDM group received a mean cisplatin dose of 66 mg/m2 and 62 mg/m2, respectively. Patients were observed for retching and/or emesis for 24 hours and completed a visual analog scale (VAS) for nausea. Six MDL 72,222 and five HDM patients had no vomiting. One MDL 72,222 and two HDM patients had one episode of emesis within 24 hours of chemotherapy. The median number of emetic episodes in the first 24 hours was 0.5 for MDL 72,222 and 1.0 for HDM patients. HDM patients were frequently asleep and were not awakened for evaluation of nausea with the VAS; 58% (70 of 120) of the HDM (mean score: 19.1 mm) and 14% (17 of 119) of the MDL 72,222 (mean score: 17.1) patients could not have VAS scores obtained (X2 = 50.74, p < 0.001). MDL 72,222 had similar efficacy with less sedation, and further trials are warranted.

Topics: Adult; Aged; Antiemetics; Cisplatin; Diphenhydramine; Drug Therapy, Combination; Female; Genital Neoplasms, Female; Humans; Lorazepam; Metoclopramide; Middle Aged; Nausea; Pilot Projects; Serotonin Antagonists; Tropanes; Vomiting

Activation of vanilloid receptors has commonly been used to facilitate neurogenic inflammation and plasma exudation to model components of the pathogenesis of migraine; however, these studies have been performed mainly in species lacking the emetic reflex. In the present studies, therefore, we used Suncus murinus, a species of insectivore capable of emesis, to investigate if the vanilloid receptor agonist resiniferatoxin is capable of modeling the emesis associated with migraine. Resiniferatoxin (100 nmol/kg, s.c.) induced an emetic response that was antagonized significantly (P<0.05) by ruthenium red (1-3 micromol), (2R-trans)-4-[1-[3,5-bis(trifluromethyl)benzoyl]-2-(phenylmethyl)-4-piperidinyl]-N-(2,6-dimethylphenyl)-1-acetamide (S)-hydroxybutanedioate (R116301; 10-100 micromol/kg), and scopolamine (1 micromol/kg), but not by dihydroergotamine (0.3-3 micromol/kg), sumatriptan (1-10 micromol/kg), methysergide (1-10 micromol/kg), tropanyl 3,5-dichlorobenzoate (MDL72222; 3-30 micromol/kg), ondansetron (0.3-3 micromol/kg), metoclopramide (3-30 micromol/kg), domperidone (3-30 micromol/kg), diphenhydramine (1-10 micromol/kg), or indomethacin (3-30 micromol/kg). The failure of a wide range of representative anti-migraine drugs to reduce retching and vomiting limits the use of this model to identify/investigate novel treatments for the emesis (and nausea) associated with migraine attacks in humans. However, the results provide further evidence for the involvement of a novel vanilloid receptor in resiniferatoxin-induced emesis and implicate both tachykinins and acetylcholine in the pathway(s) activated by resiniferatoxin in S. murinus.

Topics: Animals; Antiemetics; Butanols; Capsaicin; Cyclooxygenase Inhibitors; Dihydroergotamine; Diphenhydramine; Diterpenes; Domperidone; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Humans; Indomethacin; Malates; Methysergide; Metoclopramide; Migraine Disorders; Ondansetron; Piperidines; Ruthenium Red; Scopolamine; Serotonin Antagonists; Serotonin Receptor Agonists; Shrews; Sumatriptan; Time Factors; Tropanes; Vomiting

The aim of this manuscript is to introduce Cryptotis parva (the least shrew) as a new experimental emesis model. The chemotherapeutic agent, cisplatin, caused a dose-dependent increase in the number of animals exhibiting vomiting and retching behaviours with ED50 values of 6.43+/-1 and 7.9+/-1.2 mg/kg, respectively. The frequencies of these parameters were also dose-dependent. Intraperitoneal administration of 5-HT3 receptor antagonists (tropisetron or MDL 72222) prevented cisplatin-induced emesis and retching behaviours in the least shrew by a dose-dependent mechanism with respective ID50 values of 4.28+/-2.8 and 2.05+/-2 for emesis, and 2.71+/-4.5 and 2.52+/-2.59 for retching. Intraperitoneal injection of selective and nonselective 5-HT3 receptor agonists potently, and in a dose-dependent fashion, induced emesis in the least shrew with the following ED50 potency order: 2-methyl 5-HT approximately 5-HT (p > 0.05) <5-HTQ (p < 0.01)

Topics: Analysis of Variance; Animals; Antiemetics; Antineoplastic Agents; Cisplatin; Creatinine; Dose-Response Relationship, Drug; Drug Combinations; Female; Indoles; Male; Serotonin; Serotonin Antagonists; Serotonin Receptor Agonists; Shrews; Tropanes; Tropisetron; Vomiting

The use of high doses of cisplatin in treating cancers has been limited by two major adverse effects--emesis and peripheral neuropathies. The emesis has become largely controlled by the introduction of a new class of drugs--the 5-HT3 receptor antagonists. The current study was undertaken to determine if these drugs would also prevent cisplatin-induced neuropathy. We have used a developing rat as an animal model and determined the effects of cisplatin on morphology (loss of spinal cord calcitonin gene-related peptide (CGRP)-containing neurons) and behavior (gait abnormalities and pain perception). Rat pups from the age of 5 days were treated twice weekly for 4 weeks with cisplatin (1 mg/kg), the 5-HT3 antagonist MDL 72222 (3 mg/kg) or both. The animals were tested for pain perception (using tail-flick latencies) at 17 and 21 days of age and for a gait abnormality at 24 days of age. At 34 days of age, the animals were perfused and the lumbar region of the spinal cords stained immunocytochemically for CGRP. Our results show that cisplatin treatment resulted in a dramatic loss of CGRP neurons in the dorsal horn of the spinal cord and a corresponding increase in the animals' threshold for pain. In addition, the animals showed a pronounced gait abnormality, characterized by 'toeing-in'. Treatment with MDL 72222 not only failed to protect against the loss of CGRP neurons but also worsened the gait abnormalities seen after cisplatin treatment alone. These studies confirm and extend the list of morphological and functional adverse effects of cisplatin treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Analysis of Variance; Animals; Behavior, Animal; Calcitonin Gene-Related Peptide; Cell Count; Cisplatin; Disease Models, Animal; Gait; Immunohistochemistry; Male; Neurons; Pain Threshold; Rats; Rats, Sprague-Dawley; Serotonin Antagonists; Spinal Cord; Tropanes; Vomiting

The involvement of visceral afferent fibers and 5-HT3 or 5-HT4 receptors in the vomiting induced by oral administration of copper sulfate was investigated in beagle dogs. Vomiting induced by copper sulfate (100 mg/kg) was inhibited markedly by bilateral abdominal vagotomy and bilateral greater splanchnic nerve section. The vomiting induced by copper sulfate was inhibited by blocking 5-HT4 receptors with high doses (1 and 3 mg/kg, i.v.) of ICS 205-930. On the other hand, blocking 5-HT3 receptors with MDL 72222 (0.5 and 5 mg/kg, i.v.) or low doses (0.01 mg/kg i.v.) of ICS 205-930 had no apparent effect on the vomiting induced by copper sulfate. Oral administration of a 5-HT4 receptor agonist, 5-methoxytryptamine (5-MT), caused vomiting at a dose of 100 mg/kg, and the vomiting was inhibited markedly by abdominal visceral nerve section or a high dose (1 mg/kg, i.v.), but not a low dose (0.01 mg/kg, i.v.), of ICS 205-930. Intravenous administration of 5-MT (10 mg/kg) failed to induce vomiting. These results suggest that the abdominal visceral afferent fibers and possibly peripheral 5-HT4 receptors play an important role in the vomiting induced by oral administration of copper sulfate in dogs.

Topics: 5-Methoxytryptamine; Administration, Oral; Animals; Copper; Copper Sulfate; Dogs; Female; Indoles; Injections, Intravenous; Male; Nerve Fibers; Receptors, Serotonin; Serotonin Antagonists; Splanchnic Nerves; Tropanes; Tropisetron; Vagotomy; Viscera; Vomiting

1. Erythromycin administration is associated with gastrointestinal problems, disturbed gastrointestinal motility and emesis. This study in the dog investigates the underlying mechanisms. 2. Intestinal myoelectrical activity and the occurrence and latency of emesis were recorded in eight conscious dogs. All drugs were administered intravenously. 3. Erythromycin (7 mg kg-1) increased contractions of the proximal small intestine, and caused emesis in all fasted dogs and in 5 dogs after food. Atropine (50 mg kg-1 min-1) and hexamethonium (10 mg kg-1 h-1) partially inhibited the GI motility effects but did not significantly reduce emesis. 4. Metoclopramide at a high dose (2 mg kg-1 h-1) reduced the incidence of emesis in the presence of increased intestinal motility, but a low dose (150 micrograms kg-1 h-1) was ineffective. 5. A 5-hydroxytryptamine3 (5-HT3) receptor antagonist, MDL 72222 (1 mg kg-1), reduced emesis when given alone and combined with metoclopramide (low dose). The 5-HT4 receptor agonist BRL24924 (Renzapride, 1 mg kg-1) had no effect on emesis either alone in combination with metoclopramide. 6. In conclusion, erythromycin-induced GI motility disturbances and emesis are not causally related. Whereas the increase in intestinal smooth muscle activity is possibly cholinergically mediated, emesis occurs at least in part via a 5-hydroxytryptaminergic mechanism, but does not involve the dopamine system.

Topics: Animals; Atropine; Benzamides; Bridged Bicyclo Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cholinergic Antagonists; Dogs; Electromyography; Erythromycin; Female; Gastrointestinal Motility; Hexamethonium; Hexamethonium Compounds; Injections, Intravenous; Intestine, Small; Male; Metoclopramide; Muscle Contraction; Muscle, Smooth; Serotonin Antagonists; Tropanes; Vomiting

Two new classes of potent 5-HT3 agents have been developed and examined as inhibitors of cytotoxic drug induced emesis in the ferret and dog. The absolute configuration of the most active molecules 10 and 18 have been determined by X-ray crystallography. These two compounds are more potent than known 5-HT3 receptor antagonists both in vivo and in vitro in blocking 5-HT3 receptor activation and preventing chemotherapeutic induced emesis. Compared with 5-HT3 antagonists, such as GR 38032F, zacopride, BRL 43694, and ICS 205-930, compound 10 was more potent in (1) inhibiting binding to 5-HT3 receptor binding sites in rat cortex (Ki = 0.17 nM), (2) blocking the von Bezold-Jarisch effect in the rat (lowest effective dose, 1 microgram/kg iv), and (3) inhibiting 5-HT-induced contraction of guinea pig ileum (lowest effective concentration, 10(-9) M). This novel agent was as effective given po as when given iv in reducing cisplatin-induced emetic episodes in the ferret (ED50 = 4 micrograms/kg iv or po). A 1 mg/kg po dose of 10 virtually abolished cisplatin-induced emesis for 10 h in the ferret. However, it was inactive against apomorphine or copper sulfate-induced vomiting. These data, coupled with receptor binding studies of ligands for D2-dopamine, a1, a2, 5-HT1, 5-HT2, and muscarinic receptors demonstrate that 10 is a highly selective 5-HT3 receptor antagonist with remarkable potency in vivo.

Topics: Amides; Animals; Antiemetics; Benzamides; Benzofurans; Bridged Bicyclo Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cerebral Cortex; Cisplatin; Dogs; Ferrets; Guinea Pigs; Ileum; Molecular Structure; Muscle Contraction; Rats; Serotonin; Serotonin Antagonists; Structure-Activity Relationship; Vomiting; X-Ray Diffraction

The involvement of visceral afferent fibers and 5-HT3 receptors in the emesis induced by cisplatin was studied in beagle dogs. The emesis induced by cisplatin (3 mg/kg, i.v.) was inhibited by the intravenous administration of ICS205930 (2 x 0.01 or 2 x 0.1 mg/kg) and MDL72222 (2 x 0.5 mg/kg), 5-HT3 receptor antagonists, but not by the intravenous administration of metoclopramide (2 x 0.5 mg/kg), a dopamine D2 receptor antagonist. The cisplatin-induced emesis was also suppressed by the intravenous administration of para-chlorophenylalanine (300 mg/kg/day for 3 days), an inhibitor of 5-HT synthesis. On the other hand, the administration of ICS205930 into the IVth ventricle (2 x 0.01 mg/animal) had no effects on the cisplatin-induced emesis. The cisplatin-induced emesis was completely inhibited by abdominal vagotomy and splanchnicectomy, but not by splanchnicectomy alone. On the contrary, the emesis induced by apomorphine was suppressed by the intravenous (0.1 mg/kg) or intracerebroventricular (0.05 mg/animal) administration of metoclopramide, but not by visceral nerve section. These results strongly suggest that cisplatin evokes emesis mainly by acting on the vagal afferent terminals through the release of 5-HT and that peripheral 5-HT3 receptors are involved in this action.

Topics: Afferent Pathways; Animals; Cisplatin; Dogs; Female; Indoles; Male; Metoclopramide; Receptors, Serotonin; Serotonin Antagonists; Tropanes; Tropisetron; Vagus Nerve; Vomiting

The locations of serotonin-3 (5-HT3) receptors involved in initiating vomiting (emesis) were assessed by cutting visceral afferents or lesioning the area postrema. The 5-HT3 receptor agonists phenylbiguanide (PBG) and 2-methyl-5-HT were shown to induce vomiting and related prodromal signs (e.g., licking, swallowing) in nonoperated cats. Two-methyl-5-HT, but not PBG, also usually produced defecation and sometimes urination. Most studies were conducted using PBG, which induced vomiting in 40/49 (82%) cats at doses of 8.0 mg/kg i.p. or less (thresholds ranged from 2-8 mg/kg, median 5 mg/kg). Latencies to the first episode ranged from 4 to 21 min (median 7.5 min). PBG-induced vomiting was blocked by the 5-HT3 receptor antagonist MDL 72222. Lesions of the area postrema had no apparent effect on vomiting induced by PBG or by electrical stimulation of abdominal vagal afferents. In contrast, the threshold of PBG-induced vomiting was increased by supradiaphragmatic vagotomy and greatly increased by splanchnic nerve section. Thus, abdominal visceral afferents, but not the area postrema, play an important role in mediating vomiting induced by i.p. injection of the 5-HT3 receptor agonist PBG. The mechanisms by which vomiting is induced by PBG as compared to the cancer chemotherapeutic drug cisplatin are discussed.

Topics: Animals; Biguanides; Cats; Cerebral Ventricles; Female; Male; Serotonin; Serotonin Antagonists; Splanchnic Nerves; Tropanes; Vagotomy; Vomiting

Despite a number of significant advances over the past decade, prevention and treatment of chemotherapy-induced emesis remain formidable problems, particularly with cisplatin-containing regimens. Nearly one third of patients receiving high-dose cisplatin still experience substantial emesis despite the best available conventional antiemetics, and the toxic effects of these agents remain quite troublesome. In recent years, a new class of agents, the serotonin antagonists, has been identified. These agents hold promise for clinical utility in a wide range of areas. Selective antagonists of the serotonin (5-hydroxytryptamine) type 3 (5-HT3) receptor have proven in early clinical trials to be potent antiemetic agents in patients receiving cytotoxic chemotherapy, with efficacy comparable to or superior to that of conventional antiemetics. Toxic effects to date with the 5-HT3 receptor antagonists have been modest. The current state of knowledge with respect to these agents as antiemetics for patients receiving cytotoxic chemotherapy is summarized.

Topics: Antiemetics; Benzamides; Bridged Bicyclo Compounds; Bridged Bicyclo Compounds, Heterocyclic; Granisetron; Humans; Imidazoles; Indazoles; Indoles; Metoclopramide; Ondansetron; Quinolizines; Receptors, Serotonin; Serotonin Antagonists; Tropanes; Tropisetron; Vomiting

A total of 25 patients (5 groups of 5) were given single i.v. doses of 5, 10, 20, 40 and 60 mg MDL 72,222 (a 5-HT3 receptor antagonist) at 15 minutes before the commencement of a 24-h cisplatin infusion (total dose, 120-200 mg) to determine the efficacy and safety of the former in the prevention of nausea and vomiting associated with such chemotherapy. All patients completed the study. The time to onset of vomiting was significantly correlated with dose. All patients vomited following doses of 5 and 10 mg (range, 1-6 episodes), with onset being noted at 5-8 h. At the 20-mg level, only one episode of vomiting was observed in 3/5 patients, with onset being observed at 18-22 h. Following doses of 40 and 60 mg, 3/10 patients did not vomit; in the remaining patients the number of episodes ranged from 1 to 6, but a significant increase occurred in the time to onset of symptoms. At the higher doses, nausea tended to be milder in nature both at onset and at the time of maximal severity. A similar dose-effect trend was seen in the time to onset of the maximal severity of nausea. The time to and requirement for escape medication was similarly extended at doses of greater than or equal to 20 mg MDL 72,222. Pain at the injection site in one patient was the only unwanted effect associated with MDL 72,222. The results suggest that the i.v. injection of 20 mg MDL 72,222 should be further explored in the control of nausea and vomiting associated with cisplatin administration.

Topics: Adult; Antiemetics; Cisplatin; Drug Evaluation; Female; Humans; Injections, Intravenous; Male; Middle Aged; Nausea; Neoplasms; Serotonin Antagonists; Time Factors; Tropanes; Vomiting

5-Hydroxytryptamine3 antagonists have been reported to prevent emesis elicited by cisplatin and radiation. This study investigated the possibility that drugs with this mechanism of action may be useful in preventing emesis elicited by other stimuli. The drugs ICS 205-930 (0.1 and 1.0 mg/kg) and MDL 72222 (0.1 and 1.0 mg/kg) were administered SC to cats before challenging them with either provocative motion or an emetic dose of xylazine. In no instance was a significant reduction in emesis evident. Zacopride was also administered before motion testing (0.01 to 10.0 mg/kg) and found to not have efficacy. To test the possibility that species or route of administration were factors in the negative results, 1.0 mg/kg of ICS 205-930 was administered SC before IV infusion of 7.5 mg/kg of cisplatin. There was a total suppression of emesis for the duration of the six-hour observation periods. This result verifies other work which found 5-hydroxytryptamine3 antagonists to be effective in preventing emesis elicited by cancer chemotherapeutic treatments. However, there is no evidence that they are effective in other syndromes, such as motion sickness and xylazine-induced emesis.

Topics: Animals; Antiemetics; Benzamides; Bridged Bicyclo Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cats; Cisplatin; Indoles; Motion Sickness; Receptors, Serotonin; Serotonin Antagonists; Thiazines; Tropanes; Tropisetron; Vomiting; Xylazine

MDL 72222, the selective 5-hydroxytryptamine (5-HT) M-receptor antagonist, prevented or reduced cisplatin-induced emesis in ferrets. It is suggested that cisplatin-induced, and possibly other cytotoxic drug-induced vomiting may involve a 5-HT M-receptor mechanism.

Topics: Animals; Cisplatin; Ferrets; Male; Receptors, Serotonin; Serotonin Antagonists; Tropanes; Vomiting