SEARCH · Search PubMed

Results for “EMETICS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources

PubMed1980

Motion sickness in the squirrel monkey.

Because it is of the same taxonomic order as man, the squirrel monkey has been introduced as a nonhuman primate model for the study of such aspects of motion and space sickness as susceptibility, prevention, treatment, and neural mechanisms. In this study on susceptibility, the specific aims were to examine the effects of combined vertical rotation and horizontal acceleration, phenotype, sex, visual cues, morning and afternoon testing, and repeated test exposures on incidence, frequency, and latency of emetic responses. The highest emetic incidence of 89%, with an emetic frequency of 2.0, during 60 min, and a latency of 19 min from onset of testing, occurred at 25 rpm and 0.5 Hz linear acceleration. Susceptibility--defined by incidence, frequency, and/or latency of emesis--was significantly higher in Bolivian than Colombian phenotypes, in the presence of visual cues, in males, but not at different periods of the day or with two successive test exposures. Since the emetic responses were quite similar to man in the eliciting motion stimuli, it was concluded that the squirrel monkey represents a very suitable primate model for studies of motion and space sickness.

Animals↗

PubMed1982

Antiemetic activity of butorphanol against cisplatin-induced emesis in ferrets and dogs.

The analgesic agent butorphanol was evaluated for its ability to block cisplatin-induced emesis in ferrets and dogs. In ferrets, butorphanol (0.15, 0.3, or 0.45 mg/kg; expressed in terms of the tartrate salt) administered sc 30 minutes prior to cisplatin (8 mg/kg iv) reduced the number of emetic episodes but did not eliminate them. When these doses of butorphanol were administered 30 minutes before and 30 and 90 minutes after cisplatin, they caused a dose-related reduction in the number of emetic episodes; there was complete protection at a dose of 0.45 mg/kg/injection. In dogs, butorphanol (0.185 or 0.37 mg/kg/injection, expressed in terms of the tartrate salt) was administered sc on the same multiple-dose schedule used in the ferrets; this caused a nearly complete elimination of the emetic response to cisplatin (3 mg/kg iv). Butorphanol caused some sedation in both species at effective antiemetic doses but had no effect on the antitumor activity of cisplatin against murine L1210 leukemia. Naloxone blocked the antiemetic effect of butorphanol in ferrets, indicating the involvement of opiate receptors. The results of these studies suggest that butorphanol may be useful clinically in mitigating the emetic effects of cisplatin.

Animals↗

PubMed1994

Emesis and anti-emesis.

From a consideration of the above evidence, it is possible to hypothesize that the 5-HT3 receptors, which are located both in the gut and in the AP/NTS, may play an important and perhaps pivotal part in the mechanism(s) of action of chemotherapy and radiotherapy to induce emesis in animals and humans and represent the anti-emetic sites of action of ondansetron and related agents (see Fig. 1). The value of ondansetron and the 5-HT3 receptor antagonists has been to greatly improve the treatment of nausea and emesis in the cancer patient and to cause a renaissance in emesis research. The 5-HT3 receptor antagonists have helped to redefine the phases of chemotherapy induced emesis and establish the first clear neurotransmitter links in the emetic reflex. It has also encouraged the analysis of emetic mechanisms that will identify further points for pharmacological intervention that may ultimately provide "broad spectrum" anti-emetic agents. Such compounds would further improve the quality of life and treatment of the cancer patient, leading to increased success in the treatment of malignant tumours.

Animals↗

PubMed1997

[Value of the combination of oral ondansetron with methylprednisolone as soon as the first cure in mild emetogenic chemotherapy. Groupe français d'étude de l'ondansétron].

This multicentre randomized single-blind parallel group study compared the efficacy of oral ondansetron plus methylprednisolone (OND+MPS) with conventional antiemetic strategies (TH) over 4 consecutive courses in moderately emetogenic chemotherapy. This study was conducted in naive patients receiving a minimum of 3 cytotoxics including adriamycin (> or = 35 mg/m2) and cyclophosphamide (> or = 500 mg/m2) plus an other alkylating agent. Of the 364 patients included in the study, 70% had a breast cancer and 30% a lymphoma. Patients were divided into two groups. On day 1, one group of patients received OND (8 mg, po) 2 hours before chemotherapy, followed by a slow intravenous injection of MPS (120 mg) 30 minutes before chemotherapy. Eight hours after the start of chemotherapy, patients received OND (8 mg, po) and MPS (16 mg, po). On days 2-4, patients received OND (8 mg, po) and MPS (16 mg, po) twice daily. The second group of patients received conventional antiemetic treatment (benzamide plus corticosteroids with or without benzodiazepins). The primary efficacy parameter was defined as complete control of emesis (0 emetic episodes) over 4 consecutive courses of chemotherapy. In the OND+MPS group, 63% of patients experienced complete control of emesis versus 33% in the TH group (p < 0.001). The secondary parameters (percentage of days with no emetic episodes, control of emetic episodes, grade of nausea at each course, patient preference and quality of life evaluation) were always significantly better in the OND+MPS treated group. The percentage of days without any emetic episode over the 4 courses of chemotherapy was 91% in the OND+MPS group and 75% in the TH group (p < 0.001). Ninety-two percent of patients from OND+MPS group preferred to continue their treatment versus 76% in the TH group (p < 0.001). Concerning the quality of life assessed by FLIC and FLIE questionnaires, the analysis showed a significant difference at the end of the treatment in favor of OND+MPS (p = 0.037 and 0.0075 respectively). This study showed the interest in using the combination OND+MPS right from the first course of moderately emetogenic chemotherapy.

Adult↗

PubMed1988

Emesis induced by 4-(m-chlorophenylcarbamoyloxy)-2-butynyltrimethylammonium chloride (McN-A-343): evidence for a predominant central muscarinic M1 mediation.

The emetic action of 4-(m-chlorophenylcarbamoyloxy)-2- butynyltrimethylammonium chloride (McN-A-343) was investigated in the unanaesthetized cat, after it was injected into the cerebral ventricles, through chronically-implanted cannulae. Intracerebroventricular injection of McN-A-343 produced dose-dependent and shortlasting emesis, which was not completely abolished after ablation of the area postrema. The predominantly selective muscarinic M1 antagonist, pirenzepine as well as the mixed muscarinic M1 and M2 antagonist, atropine, injected into the cerebral ventricles, attenuated or abolished the emesis evoked by intracerebroventricular McN-A-343. Both atropine and pirenzepine produced dose-dependent inhibition of the emesis evoked by McN-A-343. However, the ID50 value for atropine was approximately five times greater than that for pirenzepine. Abolition of McN-A-343-induced emesis only occurred with the largest dose of atropine (1 mg). On the other hand, selected ganglionic blocking agents, an alpha- and beta-adrenoceptor blocking agent, a dopamine antagonist, a 5-hydroxytryptamine antagonist and an antihistamine, all injected into the cerebral ventricles, had no significant effect on emesis evoked by McN-A-343, similarly injected. The emetic response to intracerebroventricular injection of McN-A-343 was attenuated or abolished in cats pretreated with hemicholinium-3, triethylcholine, reserpine and 6-hydroxydopamine, intracerebroventricularly. On the contrary, the emetic response to intracerebroventricular injection of McN-A-343 was not altered in cats pretreated with intracerebroventricular injections of bretylium, alpha-methyl-p-tyrosine and 5,6-dihydroxytryptamine. It is postulated that the emesis produced by McN-A-343, injected into the cerebral ventricles, is mediated through muscarinic M1 receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

(4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethy↗

PubMed1995

Emesis of rhesus monkeys induced by intragastric administration with the HEp-2 vacuolation factor (cereulide) produced by Bacillus cereus.

To study the correlation between emetic toxin and HEp-2 vacuole activity produced by Bacillus cereus isolated from an outbreak of vomiting-type food poisoning, some properties and emetic activities of both purified HEp-2 factor (cereulide) and partially purified factor to rhesus monkeys were determined. The results indicate that both cereulide and partially purified factor were very stable to digestion with proteolytic enzymes, different pH, and heating. Vomiting was induced in the rhesus monkeys orally administered with both substances. From these findings, cereulide (or HEp-2 vacuole factor) is strongly suggested to be an emetic toxin itself.

Administration, Oral↗

PubMed2006

Conditioned gaping in rats: a selective measure of nausea.

When intraorally infused with a flavored solution previously paired with an emetic drug, rats display a characteristic gaping reaction that reflects conditioned nausea in this species that is unable to vomit. The commonly used conditioned taste avoidance measure, is not a selective measure of nausea because nearly every drug tested (even rewarding drugs) is capable of producing a conditioned taste avoidance. In contrast, only emetic drugs produce conditioned gaping reactions in rats, and anti-emetic drugs interfere with the establishment and the expression of conditioned gaping reactions but do not interfere with conditioned taste avoidance. The conditioned gaping reaction can be used as a pre-clinical tool to evaluate the side effects of nausea that might result from newly developed pharmaceutical agents.

Animals↗

PubMed2004

Differential activity of drugs to induce emesis and pica behavior in Suncus murinus (house musk shrew) and rats.

We have previously reported that emetic stimuli induce kaolin ingestion behavior (pica behavior) in rats and mice (i.e., species that do not have the emetic reflex) and that the behavior may be analogous to gastrointestinal discomfort, such as nausea and emesis. We hypothesized that pica behavior may also occur in species capable of vomiting and that it may serve as an additional index of discomfort relevant to antiemetic drug development. The present experiments were conduced using Suncus murinus and rats and kaolin consumption was measured at 24 h after the administration of nicotine (1.25-5 mg/kg, s.c.), copper sulfate (10-120 mg/kg, p.o.), lithium chloride (50-200 mg/kg, i.p.) and cisplatin (1-30 mg/kg, i.p.). In S. murinus, all treatments, excepting lithium chloride, were emetic but none induce kaolin consumption. Conversely, all treatments induced kaolin consumption in rats without inducing emesis. The results indicate that pica behavior is not likely to be useful to assess gastrointestinal discomfort in S. murinus.

Animals↗

PubMed1987

Treatment of paraquat poisoning in man: methods to prevent absorption.

Theoretically, absorption of an ingested dose of paraquat may be reduced by gastric lavage, induced emesis, whole-gut lavage or by the oral administration of absorbent substances. Animal experiments suggest that paraquat is absorbed poorly from the stomach and absorbed incompletely (less than 5%) from the small intestine over a 1-6 h period. Although gastric lavage would therefore seem a logical way to ameliorate the toxicity of an ingested dose of paraquat, peak plasma concentrations are attained rapidly and evidence for the efficacy of gastric lavage in man is poor. In 1977, a potent emetic (PP796) was added to liquid and solid formulations of paraquat because experiments in primates had demonstrated a fivefold reduction in toxicity. In man, ingestion of formulations containing an emetic is more likely to cause spontaneous vomiting within 30 min than non-emetic preparations. However, definite evidence of benefit, as judged by improved patient prognosis, has yet to be established. Gut lavage has been shown to remove only a small proportion of an ingested dose of paraquat. At the flow rates employed in man (75 ml/min), approximately 0.5-1.0 litres of lavage fluid/h may be absorbed across the intestinal wall. Since there is a theoretical risk of increasing paraquat absorption, the use of whole-gut lavage cannot be recommended. Bipyridilium herbicides are absorbed by soil and clay minerals, and montmorillonite in particular has been shown to be a strong binding agent in vitro. Accordingly, the use of Fuller's Earth (calcium montmorillonite) and Bentonite (sodium montmorillonite) for the treatment of poisoning has been investigated in animal models.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Compounds↗

PubMed1984

Role of the area postrema in vomiting and related functions.

Before 1949, the vomiting center was said to be located in the dorsal vagal nuclei of the medulla, but it was uncertain whether two centers existed separately for the control of direct and reflex actions of emetic agents. Borison and Wang then used a stereotaxic technique with electrical stimulation to localize the vomiting center in the reticular formation at a measurable distance from the dorsal vagal nuclei. They also formulated the concept of a separate emetic chemoreceptor trigger zone (CTZ) so that the vomiting center itself is not sensitive to emetic agents and serves solely to coordinate the reflex process. The CTZ was soon identified with the area postrema (AP), but the question remains unanswered whether the CTZ constitutes part or all of tht circumventricular organ. Furthermore, different chemosensory functions, as for defecation and certain forms of autonomic expression, may be represented regionally within the AP. Species that are unable to vomit, e.g., rodents, show other postrema-mediated effects as radiation-induced gastric stasis and drug-induced conditioned taste aversion. In sheep, digitalis-induced arrest of rumination is prevented by postremectomy. It is suggested that these behavioral end points in nonvomiting species may serve for biological assay of antinauseant drugs. Finally, a tabular summary is given of known causes of vomiting in which the AP has been implicated.

Animals↗

PubMed2000

Cytotoxic chemotherapy has minimal direct effect on gastric myoelectric activity in children with 5HT(3) antagonist prophylaxis.

BACKGROUND: Cancer patients receiving cytotoxic chemotherapy frequently develop nausea and vomiting. The direct effect of chemotherapy on gastric pacemaker is not clear. The objective of this study was to assess the direct interference of gastric electrical activity by chemotherapeutic agents as a possible cause of vomiting using electrogastrography (EGG). PROCEDURE: Fasting surface EGGs were recorded in 24 children with malignancy and 24 age-matched controls. All oncology patients received the intravenous prophylatic ondansetron. According to the known emetic potential of the medications they received, the children were divided into mild, moderate, and severe groups. The EGG recordings of oncology patients were segmented into prechemotherapy period, chemotherapy period, and emetic period. The EGG data from each period were collected and analyzed (paired t-test and Mann-Whitney U test). RESULTS: There were 24 children (M:F ratio: 14:10), with a mean age of 9.6 years. Eight children vomited during the course of recording (0/3 from the mild group, 2/6 from the moderate group, and 6/15 from the severe group). The average duration of intravenous medication infusion was 7.8 hr (range 2 min to 24 hr). There was no difference between the EGG of normal control and the prechemotherapy EGG of the oncology patients. No difference was detected between the EGG data from the prechemotherapy period and the chemotherapy period. A statistically significant increase in tachygastria was detected in emetic periods (28 episodes, mean duration 5 min; P = 0.01). CONCLUSIONS: Insignificant EGG changes during chemotherapy suggest that chemotherapy has a minimal direct effect on gastric pacemaker. Tachygastria seemed to be a secondary effect of vomiting rather than the cause of it. These preliminary findings suggest that efforts to modify gastric electrical rhythm as a means of management of chemotherapy-induced vomiting may be futile. Further studies to identify factors responsible for vomiting are warranted.

Adolescent↗

PubMed1996

Are more antiemetic trials with a placebo necessary? Report of patient data from randomized trials of placebo antiemetics with cisplatin.

BACKGROUND: Because of the predictability of significant emesis after its use, cisplatin serves as the standard emetic stimulus for trials of antiemetic drugs. To define better the incidence, severity, and pattern of emesis that follows cisplatin, facilitate the testing of new agents, and obviate the need for further placebo-controlled trials for this indication, individual patient data were compiled from completed studies with placebo antiemetics and cisplatin. METHODS: The time and number of emetic episodes during the 24 hours after cisplatin were obtained for 48 patients given a placebo antiemetic. Each was treated as part of a randomized, double-blind trial reported between 1981 and 1990. Emesis after antiemetic "rescue" therapy was also assessed. RESULTS: Emesis occurred in 47 of 48 patients (98% observed rate, 95% confidence interval, 89-99%). The median number of emetic episodes during the 24 hours after cisplatin was 6. Emesis continued after rescue in 77% of patients. CONCLUSIONS: Cisplatin caused severe emesis that persisted despite rescue in placebo-treated patients. Using the data presented, any therapy preventing acute emesis in 8 or more of the 48 individuals receiving cisplatin > 50 mg/m2 was an active antiemetic (P = 0.05). The four trials discussed here documented the antiemetic effectiveness of granisetron, metoclopramide, and ondansetron. The placebo-treated patients studied can serve as a control group for testing new therapies. Because of the certainty of severe emesis after cisplatin, and the availability both of these data and several proven drugs for this condition, prospective comparisons of antiemetics should employ active control medications.

Adult↗

PubMed1984

Intravenous metoclopramide: prevention of chemotherapy-induced nausea and vomiting. A preliminary evaluation.

The authors tested the safety and efficacy of intravenous metoclopramide in the prevention of chemotherapy-induced nausea and vomiting. Those studied included hospitalized patients receiving their initial treatment with potent, emetogenic non-cisplatin-containing regimens, and outpatients receiving both their initial and maintenance non-cisplatin-containing chemotherapy. Fifty patients received metoclopramide with one or more of three intravenous metoclopramide dosage schedules, based on whether they received their chemotherapy on an inpatient or outpatient basis. Of the 50 patients treated, 39 (78%) achieved total protection (no emesis), and 9 (18%) attained major antiemetic protection (one or two emeses) when all dosage schedules of metoclopramide were combined. Therefore, total or major antiemetic protection was observed in 48 of 50 patients (96%) receiving a broad range of potentially emetogenic chemotherapy. Antiemetic protection was shown not to depend on the schedule of metoclopramide dosing used, but rather on the emetic potential of the chemotherapeutic agents or combinations employed. In addition, previously treated patients in whom chemotherapy-related nausea or vomiting had posed a significant problem in the past, were shown to have an overall lower incidence of total antiemetic and antinausea protection as compared with patients who were previously untreated or did not experience emesis with prior chemotherapy. Thirty patients experienced no nausea or vomiting with intravenous metoclopramide; in the 20 patients who experienced nausea, its incidence was shown to be directly proportional to the emetic potential of the chemotherapy agents employed. Side effects were dose-related, however none were serious enough to warrant drug withdrawal. It is concluded that intravenous metoclopramide possesses significant antiemetic activity in patients receiving potent, non-cisplatin-containing chemotherapy. The dosage and scheduling required to provide total protection against nausea and vomiting appears to be dependent on the inherent emetic potency of the chemotherapy used. Further studies involving large numbers of patients are required to determine the optimal dosage and scheduling of this agent.

Antineoplastic Agents↗

PubMed1995

Randomized, double-blind comparison of a prochlorperazine-based versus a metoclopramide-based antiemetic regimen in patients undergoing autologous bone marrow transplantation.

BACKGROUND: Highly emetogenic combination alkylator therapy is routinely used in autologous bone marrow transplantation for treatment of eligible patients with solid tumors. Antiemetic therapy remains less than optimal in this setting. METHODS: One hundred twenty-six patients with cancer receiving high dose cisplatin, cyclophosphamide, and carmustine with autologous bone marrow support were randomized to receive one of four double-blinded antiemetic regimens: 4-day continuous infusion prochlorperazine (6 mg/m2 intravenous [i.v.] loading dose followed by 1.5 mg/m2/hour) or metoclopramide (80 mg/m2 iv loading dose followed by 20 mg/m2/hr) each with either dronabinol 5 mg/m2 or placebo capsules for two doses before carmustine on the last day of chemotherapy. All subjects received scheduled lorazepam and diphenhydramine throughout the 4-day study period. Efficacy was measured by the Emetic Process Rating Scale and the Rhodes Index of Nausea and Vomiting (INV) Form 2. RESULTS: One hundred six patients completed the study and were fully evaluable. The median number of emetic episodes on the metoclopramide study arm were: 1 (0-7, day -6), 1 (0-6, day -5), 2 (0-9, day -4), and 2 (0-10, with dronabinol day -3) or 2 (0-7, no dronabinol day -3) and on the prochlorperazine study arm were: 4 (0-12, day -6), 0 (0-8, day -5), 0 (0-12, day -4) and 2.5 (0-9, with dronabinol day -3) or 2 (0-12, no dronabinol day -3). Metoclopramide was significantly better on the first day of therapy (day -6, P < .002) and prochlorperazine was significantly better on the third day of therapy (day -4, P < 0.002). There was no significant difference among any of the four arms on the last day of chemotherapy (day -3), or when the median number of emetic episodes over the total study period were compared. The patients' assessment of nausea, vomiting, and retching on the INV Form 2 was consistent with the observer ratings. Toxicities requiring dose reduction or discontinuation of antiemetic drugs included diarrhea, cardiac arrhythmias, sedation, anxiety, and akathisia. CONCLUSIONS: Both metoclopramide and prochlorperazine in combination with lorazepam and diphenhydramine offer good control of nausea and vomiting although the sedation and low risk for cardiac toxicity limit the regimen to an inpatient setting with close monitoring. No regimen was clearly superior during the entire treatment period but prochlorperazine offered more consistent control after the first day.

Adult↗

PubMed2001

Delayed nausea and vomiting in children receiving antineoplastics.

BACKGROUND: The nature and prevalence of delayed antineoplastic-induced nausea and vomiting have not been well-described in children. This study describes the extent of delayed nausea and vomiting in children receiving antineoplastic agents as well as the drug therapies initiated in an attempt to prevent or manage it. PROCEDURE: All children receiving antineoplastics were eligible for study entry. The date and time of each emetic episode were recorded on each day antineoplastics were given and for 3 days thereafter. Nausea was self-assessed daily by children who were older than 3 years and were not developmentally delayed. Diet was also assessed daily. The emetic response, median nausea rating and median diet achieved were described. RESULTS: The emetic response of 124 children who received 174 antineoplastic cycles was evaluated. Most cycles (137/174;79%) were not associated with delayed vomiting. Cycles which included cisplatin, carboplatin, or cyclophosphamide; involved antineoplastic therapy given over 2 or more consecutive days; or were accompanied by vomiting during the acute phase were associated with a significantly higher incidence of delayed vomiting. Moderate to severe nausea was reported on 58% (267/459) of study days. No antiemetics were given on most study days (412/522;79%); nevertheless, most of the study days (381/412;93%) which were unaccompanied by antiemetic support during the delayed phase were completely free from vomiting. Antiemetics were most often given as single agents (ondansetron: 54 study days; dimenhydrinate: 17 study days; dexamethasone: 6 study days). Diet was largely unaffected during the study period. CONCLUSIONS: Antineoplastic-induced delayed nausea and vomiting may be less prevalent in children than in adults. Routine antiemetic administration during the delayed phase may not be warranted in all patients. Med Pediatr Oncol 2001;37:115-121.

Adolescent↗

PubMed1997

Clonidine-induced emesis: a multitransmitter pathway concept.

The emetic effect of clonidine injected into the cerebral ventricles through chronically implanted cannulae was investigated in unanaesthetized cats. Clonidine (0.1-300 micrograms) induced dose-dependent and shortlasting emesis. The emesis induced by the supramaximal dose of clonidine (100 micrograms) was not abolished after the ablation of area postrema. Both the alpha 2 adrenoceptor blocking agent idazoxan and the mixed alpha 1 and alpha 2 adrenoceptor antagonist phenoxybenzamine, injected intracerebroventricularly, attenuated or abolished the emesis induced by clonidine (100 micrograms). On the other hand, the alpha 2 adrenoceptor blocking agent yohimbine, the alpha 1 adrenoceptor blocking drug prazosin and the non-selective beta-adrenoceptor antagonist propranolol, injected into the cerebral ventricles, had no significant effect on clonidine-induced emesis. The antimuscarinic drug atropine injected into the cerebral ventricles prevented the clonidine-induced emesis in a dose-dependent manner. The dopamine antagonist chlorpromazine, the 5-hydroxytryptamine blocking agent methysergide and the histamine H1 and H2 receptor antagonists, antazoline and cimetidine, injected intracerebroventricularly reduced or abolished the emesis produced by clonidine. The ganglionic blocking substance mecamylamine and the opioid antagonist naloxone, all injected into the cerebral ventricles, had no significant effect on clonidine-induced emesis. In cats pretreated with the intracerebroventricular competitive inhibitor of the synthesis of catecholamines, alpha-methyl-p-tyrosine, as well as with the inhibitor of acetylcholine synthesis hemicholinium-3, the emesis caused by clonidine was depressed or abolished. The clonidine-induced emesis was also abolished when catecholamine stores were depleted by intracerebroventricular reserpine. However, the clonidine-induced emesis was not significantly changed when 5-hydroxylryptaminergic nerve terminals were damaged by 5,6-dihydroxytryptamine. It follows, therefore, that cholinergic and noradrenergic mechanisms are of basic importance for the emetic action of clonidine. With regard to receptors, the emesis induced by clonidine injected into the cerebral ventricles, is mediated at least in part through alpha-adrenoceptors, muscarinic cholinoceptors, 5-hydroxytryptamine receptors and H1 and H2 histamine receptors. These receptors appear to be located mostly presynaptically and they transmit emetic impulses to neurones integrating them into emesis. However, the direct effect of clonidine on postsynaptic receptors cannot be excluded, particularly when muscarinic and 5-hydroxytryptamine receptors are implicated. Taken together, these results point to the existence of a multitransmitter pathway/s outside the area postrema, subserving the central regulation of emesis.

Adrenergic alpha-Agonists↗

PubMed1989

Does parenteral magnesium sulfate have an antiemetic effect during chemotherapy with cis-platinum?

Cisplatin is a chemotherapeutic agent with a high emetic potential; it can lead to hypomagnesemia, which is caused by a renal wasting. Because of beneficial effects of magnesium in the therapy of motor disorders of the upper gastrointestinal tract and its sedative, anticonvulsive effect in eclampsia, we tested parenteral magnesium sulfate as a potential antiemetic in patients receiving cisplatin. A prospective, randomized, double-blind, cross-over study was carried out in 20 patients receiving greater than or equal to 60 mg/m2 cisplatin. A standard antiemetic regimen consisting of a single dose of 10 mg diazepam and five times 0.5 mg/kg metoclopramide (every 2 h) was used. Simultaneously, 8 g magnesium sulfate or isotonic sodium chloride was infused over 4.5 h. The efficacy of magnesium was analyzed with an emetic score system; no difference was found between magnesium sulfate and sodium chloride. Only two patients were hypomagnesemic, and they had a better emetic score with the magnesium infusion. We conclude that the i.v. administration of magnesium during cisplatin therapy has no antiemetic effect, at least in normomagnesemic patients.

Adolescent↗

PubMed1987

High-dose metoclopramide by infusion: a double-blind study of plasma concentration-effect relationships in patients receiving cancer chemotherapy.

We have carried out a randomized, double-blind trial to investigate the relationship between the dose and plasma concentration of metoclopramide and its anti-emetic efficacy and adverse effects in patients receiving cancer chemotherapy. Seventeen patients received four different infusion regimens of high-dose metoclopramide in random order with four consecutive courses of chemotherapy, to achieve an approximately eight-fold range in plasma metoclopramide concentrations. In patients receiving cisplatin the incidence of vomiting decreased with increasing metoclopramide dose, but the overall efficacy was poor. There was no relationship between anti-emetic efficacy and either dose or plasma concentration of metoclopramide in patients receiving cyclophosphamide and doxorubicin. The adverse effects of high-dose metoclopramide included diarrhoea, which increased in incidence with increasing metoclopramide dose, and sedation and extrapyramidal reactions, which were not related to dose or plasma concentration. Although anti-emetic efficacy increases with increasing metoclopramide dose in patients receiving cisplatin, high-dose metoclopramide alone does not adequately control cisplatin-induced nausea and vomiting.

Adult↗