TGR5-dependent hepatoprotection through the regulation of biliary epithelium barrier function.

OBJECTIVE: We explored the hypothesis that TGR5, the bile acid (BA) G-protein-coupled receptor highly expressed in biliary epithelial cells, protects the liver against BA overload through the regulation of biliary epithelium permeability. DESIGN: Experiments were performed under basal and TGR5 agonist treatment. In vitro transepithelial electric resistance (TER) and FITC-dextran diffusion were measured in different cell lines. In vivo FITC-dextran was injected in the gallbladder (GB) lumen and traced in plasma. Tight junction proteins and TGR5-induced signalling were investigated in vitro and in vivo (wild-type [WT] and TGR5-KO livers and GB). WT and TGR5-KO mice were submitted to bile duct ligation or alpha-naphtylisothiocyanate intoxication under vehicle or TGR5 agonist treatment, and liver injury was studied. RESULTS: In vitro TGR5 stimulation increased TER and reduced paracellular permeability for dextran. In vivo dextran diffusion after GB injection was increased in TGR5-knock-out (KO) as compared with WT mice and decreased on TGR5 stimulation. In TGR5-KO bile ducts and GB, junctional adhesion molecule A (JAM-A) was hypophosphorylated and selectively downregulated among TJP analysed. TGR5 stimulation induced JAM-A phosphorylation and stabilisation both in vitro and in vivo, associated with protein kinase C-ζ activation. TGR5 agonist-induced TER increase as well as JAM-A protein stabilisation was dependent on JAM-A Ser285 phosphorylation. TGR5 agonist-treated mice were protected from cholestasis-induced liver injury, and this protection was significantly impaired in JAM-A-KO mice. CONCLUSION: The BA receptor TGR5 regulates biliary epithelial barrier function in vitro and in vivo through an impact on JAM-A expression and phosphorylation, thereby protecting liver parenchyma against bile leakage.

Systemic bile acid sensing by G protein-coupled bile acid receptor 1 (GPBAR1) promotes PYY and GLP-1 release.

BACKGROUND AND PURPOSE: Nutrient sensing in the gut is believed to be accomplished through activation of GPCRs expressed on enteroendocrine cells. In particular, L-cells located predominantly in distal regions of the gut secrete glucagon-like peptide 1 (GLP-1) and peptide tyrosine-tyrosine (PYY) upon stimulation by nutrients and bile acids (BA). The study was designed to address the mechanism of hormone secretion in L-cells stimulated by the BA receptor G protein-coupled bile acid receptor 1 (GPBAR1). EXPERIMENTAL APPROACH: A novel, selective, orally bioavailable, and potent GPBAR1 agonist, RO5527239, was synthesized in order to investigate L-cell secretion in vitro and in vivo in mice and monkey. In analogy to BA, RO5527239 was conjugated with taurine to reduce p.o. bioavailability yet retaining its potency. Using RO5527239 and tauro-RO5527239, the acute secretion effects on L-cells were addressed via different routes of administration. KEY RESULTS: GPBAR1 signalling triggers the co-secretion of PYY and GLP-1, and leads to improved glucose tolerance. The strong correlation of plasma drug exposure and plasma PYY levels suggests activation of GPBAR1 from systemically accessible compartments. In contrast to the orally bioavailable agonist RO5527239, we show that tauro-RO5527239 triggers PYY release only when applied intravenously. Compared to mice, a slower and more sustained PYY secretion was observed in monkeys. CONCLUSION AND IMPLICATIONS: Selective GPBAR1 activation elicits a strong secretagogue effect on L-cells, which primarily requires systemic exposure. We suggest that GPBAR1 is a key player in the intestinal proximal-distal loop that mediates the early phase of nutrient-evoked L-cell secretion effects.

Optimizing antiemetic therapy in multiple-day and multiple cycles of chemotherapy.

PURPOSE OF REVIEW: Only a few studies have investigated the effect of antiemetic therapy in patients treated with multiple-day or multiple cycles of chemotherapy. The present review will assess the available data, highlight the current recommendations and draw attention towards the remaining problems in this field of antiemetic treatment. RECENT FINDINGS: Evidence-based guidelines recommend a combination of a 5-HT3-receptor antagonist and dexamethasone in the prophylaxis of nausea and vomiting in multiple-day cisplatin-based chemotherapy. In patients treated with multiple cycles of chemotherapy the addition of a NK1-receptor antagonist aprepitant to standard antiemetic therapy has increased the antiemetic effect, and multiple cycle extension studies have demonstrated that this increment in effect is sustained during multiple cycles of chemotherapy. A recent study indicated that the dopamine D2-receptor antagonist metopimazine has some additive effect on delayed symptoms induced by multiple-day chemotherapy. SUMMARY: The development of the NK1-receptor antagonist aprepitant has significantly improved the antiemetic control in patients treated with multiple cycles of chemotherapy. Far too many patients still experience considerable emetic side effects. The effect of aprepitant in multiple-day chemotherapy has yet to be defined. The effect of new antiemetic agents such as palonosetron and olanzapine also needs to be investigated in randomized trials.

Randomized, double-blind trial comparing the antiemetic effect of tropisetron plus metopimazine with tropisetron plus placebo in patients receiving multiple cycles of multiple-day cisplatin-based chemotherapy.

PURPOSE: To compare the antiemetic efficacy and tolerability of tropisetron plus metopimazine with tropisetron plus placebo during 4 cycles of multiple-day, cisplatin-based chemotherapy. MATERIALS AND METHODS: 82 chemotherapy-naive patients with germ cell cancer scheduled to 4 cycles of multiple-day cisplatin-based chemotherapy (20 or 40 mg/m(2)/day for 5 days) given every 3 weeks were included. A double-blind parallel trial design was used and patients randomized to tropisetron plus metopimazine or tropisetron plus placebo. Tropisetron was administered as a single 5 mg intravenous dose on days 1-5 and a single 5 mg oral dose on day 6, and metopimazine as 30 mg orally t.i.d. on day 1, and q.i.d on days 2-6. RESULTS: Patients were evaluable for efficacy during a total of 195 cycles. Small, but certain advantages were obtained with the combination. In cycle 1, complete protection from emetic episodes on day 1, days 1-5, days 6-9 and days 1-9 was achieved in 85.7%, 42.9%, 86.2% and 40.5% with tropisetron plus metopimazine and in 90.0%, 22.5%, 64.3% and 17.5% with tropisetron plus placebo, respectively. This difference achieved statistical significance in the overall period, days 1-9 (P = 0.029). During the entire period (days 1-9), significantly less nausea was seen in patients receiving tropisetron plus metopimazine (P = 0.027), whereas other nausea parameters did not reach statistical significance. The cumulative emetic protection rate after 4 cycles was 0.51 with tropisetron plus metopimazine and 0.25 with tropisetron plus placebo (P = 0.037). Side effects were generally few and mild with both treatments and no significant differences were seen. CONCLUSION: Tropisetron plus metopimazine is superior to tropisetron during 4 cycles of multiple-day cisplatin-based chemotherapy, but both treatments are ineffective in a number of patients. The effect of the combination seems comparable to that of ondansetron plus dexamethasone. Newer drugs such as the neurokinin(1) receptor antagonist, aprepitant, should be investigated to optimize antiemetic therapy in patients receiving multiple-day chemotherapy.

A randomized, double-blind trial assessing the efficacy and safety of sublingual metopimazine and ondansetron in the prophylaxis of chemotherapy-induced delayed emesis.

The prevention of delayed emesis following chemotherapy remains an important challenge. This randomized, double-blind, double-dummy, multicenter study was designed to compare the efficacy and tolerance of metopimazine and ondansetron at preventing nausea and emesis in patients receiving chemotherapy. Two hundred patients were evaluated for efficacy: 103 patients received metopimazine (7.5 mg x 2 t.i.d.) and 97 received ondansetron (8 mg b.i.d.) for 5 days. Patients were asked to report episodes of nausea and emesis in a diary, and quality of life (QoL) was evaluated using the Functional Living Index--Emesis questionnaire. The incidence of complete response (defined as no nausea and emesis for 5 days) did not differ between the two treatment arms (53.4% for metopimazine versus 49.5% for ondansetron; P=0.58). No significant difference was found for the incidence of emesis (23.3% for metopimazine versus 30.9% for ondansetron) or QoL. Tolerance was as expected for both drugs and comparable, except for the incidence of gastrointestinal disorders, which was significantly lower in the metopimazine group (19.4 versus 32.7%; P=0.03). We conclude that metopimazine is an alternative to ondansetron that is better tolerated for the prevention of delayed emesis in patients receiving chemotherapy.

A pilot study of ondansetron plus metopimazine vs. ondansetron monotherapy in children receiving highly emetogenic chemotherapy: a Bayesian randomized serial N-of-1 trials design.

GOALS OF WORK: Chemotherapy-induced nausea and vomiting is problematic in paediatric brain tumour treatment protocols which often discourage the use of corticosteroids as anti-emetics. The dopamine receptor antagonist, metopimazine, is an effective anti-emetic in combination with ondansetron in adults. The present study was designed to assess its efficacy in children with cancer, a group in which it has not been studied previously. PATIENTS AND METHODS: We conducted a series of randomized, multiple-crossover, double-blind, placebo-controlled N-of-1 trials comparing ondansetron/metopimazine with ondansetron monotherapy in children with brain tumours receiving highly emetogenic therapy and combined the individual results using Bayesian statistical modeling. MAIN RESULTS: Ten of twelve enrolled patients completed at least one chemotherapy cycle on study (median=2.5 cycles, range 1-11). Two patients were unable to complete any cycles, and a further three patients withdrew from the study prior to completing all cycles because of an inability to tolerate the taste of the study drug. Combination therapy increased the proportion of days during which patients had no emesis (overall odds ratio=1.52, 95% credible region=0.32-6.40, probability of odds ratio>1=72%), decreased the number of emetic episodes per day (overall rate ratio=0.67, 95% credible region=0.15-3.14, probability of rate ratio<1=75%) and decreased parents' ratings of their child's distress. The drug was more effective during the delayed chemotherapy phase than the acute phase. No adverse events were attributed to metopimazine. CONCLUSIONS: Based on this pilot study, we believe that the high likelihood that metopimazine is an effective adjunct to ondansetron monotherapy suggests that this combination therapy is worthy of further study in children receiving emetogenic chemotherapy.

Comparison of the efficacy and safety of combinations of metopimazine or ondansetron with methylprednisolone in the prevention of delayed emesis in patients receiving chemotherapy.

BACKGROUND: Delayed emesis following chemotherapy in cancer patients remains an important challenge for treatment and contributes to poor quality of life and treatment compliance. OBJECTIVES: To compare the efficacy and tolerability of associations of metopimazine and ondansetron with methylprednisolone for the prevention of delayed chemotherapy-induced nausea and emesis. METHODS: A randomised, open-label, observational, cross-over design was used to compare two treatment strategies following two consecutive sessions of chemotherapy separated by at least 1 week. Patients were randomised to treatment with sublingual metopimazine (15 mg tid) or ondansetron lyophilisate (8 mg bid) for 5 days. All patients received oral methylprednisolone (48 mg). Patients reported episodes of nausea and emesis in a diary, and completed the Functional Living Index Emesis quality of life questionnaire. Adverse events were also evaluated. RESULTS: Ninety-nine patients were included in the study, 79.5% of whom were women, with a mean age of 52.7 years. Breast cancer was the most common individual cancer and most patients were receiving combinations of cytotoxic drugs. Treatment was successful at preventing delayed emesis in 73.6% of patients during treatment with the metopimazine-methylprednisolone association and 57.5% during the ondansetron-methylprednisolone association. Analysis of discordant pairs revealed a significant benefit in favour of the methopimazine-methylprednisolone association (p = 0.006). No significant difference was observed between treatments for the overall quality of life score. The incidence of gastrointestinal disorders, particularly constipation, was significantly higher during ondansetron-methylprednisolone treatment (p = 0.0112). CONCLUSION: Methopimazine is an effective and well-tolerated alternative to setrons for the treatment of delayed nausea and emesis in patients undergoing chemotherapy.

Randomized trial of AT-1015 for treatment of intermittent claudication. A novel 5-hydroxytryptamine antagonist with no evidence of efficacy.

AT-1015 is a novel selective 5-HT2A serotonin receptor antagonist that is known to impair platelet aggregation and vasoconstriction. Serotonin has been hypothesized to contribute to claudication symptoms in individuals with peripheral arterial disease (PAD) via microvascular vasoconstrictor and thrombotic effects. AT-1015 was thus evaluated in 439 patients with claudication who were randomized in a double-blind, placebo-controlled trial comparing 10 mg, 20 mg, and 40 mg BID versus placebo for 24 weeks. Treadmill walking performance was assessed by peak walking time (PWT) and pain-free walking time (PFWT). Quality of life (QoL) was measured by the Walking Impairment Questionnaire (WIQ) and the Health Status Survey SF-36. Limb hemodynamics was assessed with the ankle-brachial index (ABI). The 40 mg arm was terminated prematurely by recommendation of the Data Safety Monitoring Committee due to an excess number of non-fatal myocardial infarctions. At study conclusion, there were no statistically significant differences in the mean change of PWT, PFWT, ABI and QoL between the 10 mg and 20 mg BID treatment groups compared with placebo. The proportion of patients who experienced an adverse event (AE) was similar across all treatment groups. Antimuscarinic and gastrointestinal AEs were more common in the AT-1015 treatment groups. Two deaths occurred: one in the placebo group and the other in the AT-1015 20 mg group. Although a prolongation of the QTc interval was observed in all groups, this was not clinically significant (QTc > 500 ms). Mean supine pulse rates were significantly increased in all AT-1015 treatment groups, consistent with predicted antimuscarinic effects. Population pharmacokinetic analysis fit a one-compartment model with first-order absorption and elimination. These data indicate that selective serotonin receptor blockade does not improve exercise tolerance or quality of life in individuals with claudication.

Ondansetron plus metopimazine compared with ondansetron plus metopimazine plus prednisolone as antiemetic prophylaxis in patients receiving multiple cycles of moderately emetogenic chemotherapy.

PURPOSE: To compare the antiemetic efficacy and tolerability of ondansetron plus metopimazine with ondansetron plus metopimazine plus prednisolone during nine cycles of moderately emetogenic chemotherapy. PATIENTS AND METHODS: A total of 221 women with stage I or II breast cancer and no prior chemotherapy who were scheduled to receive adjuvant chemotherapy with intravenous cyclophosphamide, fluorouracil and methotrexate or cyclophosphamide, epirubicin, and fluorouracil given every 3 weeks were included in a double-blind parallel trial. Patients were randomized to 3 days of oral treatment with ondansetron plus metopimazine, or ondansetron plus metopimazine plus prednisolone. Ondansetron was administered as 8 mg bid, metopimazine as 30 mg qid, and prednisolone as 50 mg qd. RESULTS: In all, 216 patients (97.7%) were assessable for efficacy during a total of 1,462 cycles. In cycle 1, complete protection from emetic episodes/nausea day 1, days 2 through 5, and days 1 through 5 was achieved in 84.4%/51.4%, 82.6%/41.3%, and 79.8%/34.9% with ondansetron plus metopimazine and in 84.1%/57.0%, 86.8%/53.8%, and 79.4%/43.0% with ondansetron plus metopimazine plus prednisolone, respectively. In cycle 1, the three-drug combination was superior only in the treatment of nausea on days 2 through 5 (P =.0497). The cumulative emetic protection rate after nine cycles was 0.52 with ondansetron plus metopimazine and 0.75 with ondansetron plus metopimazine plus prednisolone. Side effects were generally few and mild with both treatments. Constipation was the only adverse event significantly more frequent with the three-drug combination (P =.029). CONCLUSION: Ondansetron plus metopimazine plus prednisolone is highly effective and superior to ondansetron plus metopimazine during nine cycles of moderately emetogenic chemotherapy.

Antiemetic efficacy of combination therapy with granisetron plus prednisolone plus the dopamine D2 antagonist metopimazine during multiple cycles of moderately emetogenic chemotherapy in patients refractory to previous antiemetic therapy.

Effective antiemetic treatment of patients who have previously experienced chemotherapy-induced nausea and vomiting is difficult. The aim of this study was to evaluate the antiemetic efficacy of a single intravenous dose of granisetron plus a 3-day oral treatment with prednisolone 25 mg once a day plus metopimazine 30 mg four times a day in patients refractory to previous antiemetic treatment with granisetron or with prednisolone plus metopimazine. The study population was made up of 25 consecutive women with stage I or II breast cancer, who were treated with multiple cycles of adjuvant cyclophosphamide, fluorouracil plus methotrexate or cyclophosphamide, epirubicin plus fluorouracil given i.v. every 3 weeks. Patients received the three-drug combination of antiemetics during a total of 113 cycles of chemotherapy. No emetic episodes were reported in 88.9% cycles on day 1, in 94.7% cycles on days 2 through 5 and in 85.8% cycles on days 1 through 5 after chemotherapy. No nausea was reported in 43.4% cycles on day 1, in 49.6% cycles on days 2 through 5 and in 34.5% cycles on days 1 through 5. Nineteen patients (76.0%) completed the scheduled nine cycles of chemotherapy, 1 being withdrawn because of > or =5 emetic episodes and 5, because they were not satisfied with the antiemetic treatment. The treatment was well tolerated. In conclusion, granisetron plus prednisolone plus metopimazine is a highly effective antiemetic treatment in patients receiving moderately emetogenic chemotherapy refractory to antiemetic therapy with granisetron or prednisolone plus metopimazine.

AT-1015, a novel serotonin (5-HT)2 receptor antagonist, blocks vascular and platelet 5-HT2A receptors and prevents the laurate-induced peripheral vascular lesion in rats.

The serotonin (5-HT2A) antagonistic activities and the protective effect on laurate-induced peripheral vascular lesions of AT-1015, a novel 5-HT2 receptor antagonist, were investigated. In platelet aggregation, AT-1015 selectively inhibited in vitro 5-HT2A receptor-mediated aggregation, and the activity was almost equivalent to that of ketanserin (5-HT2A/2C receptor antagonist) and 100 times more potent than sarpogrelate (5-HT2A receptor antagonist). AT-1015 also inhibited 5-HT2A receptor-mediated aggregation by oral administration in rat, and the dose required for inhibition was equivalent to ketanserin. In a 5-HT-induced vasoconstriction study in rat, AT-1015 slightly reduced maximal contraction and caused a rightward shift of the concentration-response curve (pKB value, 9.5), which was unlike competitive inhibitors such as ketanserin and sarpogrelate (pA2 value, 9.3 and 8.7, respectively). Moreover, the ex vivo inhibitory activity significantly remained after oral administration (1 mg/kg). In the rat peripheral vascular lesion model, AT-1015 (1 mg/kg, p.o.) effectively prevented progression of peripheral lesions, and it was more potent compared with ketanserin, sarpogrelate, and cilostazol. These results suggest that AT-1015 is a potent 5-HT2A receptor antagonist, and its insurmountable antagonism may be relevant to its therapeutic potential in peripheral vascular disease.

Granisetron compared with prednisolone plus metopimazine as anti-emetic prophylaxis during multiple cycles of moderately emetogenic chemotherapy.

This randomized, double-blind, double-dummy parallel study compared the anti-emetic efficacy and tolerability of the serotonin antagonist granisetron with prednisolone plus the dopamine D2 antagonist metopimazine during nine cycles of moderately emetogenic chemotherapy. Chemotherapy naive women with stage I or II breast cancer scheduled to intravenous cyclophosphamide, fluorouracil and methotrexate or cyclophosphamide, epirubicin and fluorouracil every 3 weeks were included. Patients received a single intravenous dose of granisetron 3 mg or a 3-day oral treatment with prednisolone 25 mg once a day plus metopimazine 30 mg four times a day. A total of 223 women were enrolled and 218 patients (97.8%) were evaluable for efficacy. Granisetron (n = 109) was superior to prednisolone plus metopimazine (n = 109) in the prophylaxis of acute nausea and vomiting during the first cycle of chemotherapy (P < 0.001) and prednisolone plus metopimazine was superior on days 2-5 (P = 0.002). Overall, granisetron was superior on days 1-5 (P = 0.009). The median number of cycles completed with granisetron was five (95% confidence interval 4-6) compared with two (95% confidence interval 2-2) for prednisolone plus metopimazine (P = 0.0019). Constipation and rash were reported more frequently with granisetron (P < 0.001 and P = 0.043 respectively) and palpitations more frequently with prednisolone plus metopimazine (P = 0.015). In conclusion, the number of cycles completed with granisetron was significantly higher than the number completed with prednisolone plus metopimazine, but the anti-emetic efficacy of both treatments declined during multiple cycles of moderately emetogenic chemotherapy.

Randomized, double-blind comparison of ondansetron versus ondansetron plus metopimazine as antiemetic prophylaxis during platinum-based chemotherapy in patients with cancer.

PURPOSE: To investigate the antiemetic effect and tolerability of the 5-hydroxytryptamine3(5-HT3) antagonist ondansetron plus the dopamine D2 antagonist metopimazine versus ondansetron alone in patients receiving platinum-based chemotherapy. PATIENTS AND METHODS: One hundred eleven chemotherapy-naive patients who were scheduled to receive two consecutive courses of platinum-based chemotherapy were randomized between ondansetron 8 mg intravenously (IV) followed by 8 mg orally twice a day plus metopimazine 35 mg/m2 as a 24-hour continuous infusion followed by 30 mg orally four times a day for 4 days, or ondansetron plus placebo. The study used a double-blind, crossover, placebo-controlled design. RESULTS: Ninety-four patients completed the crossover. Complete response (CR; no emetic episodes) was obtained on day 1 in 77.7% of the patients who received the combination versus 50.0% of those who received ondansetron alone (P = .00002), and in 51.7% versus 31.0% on days 2 to 6 (P = .0009). The overall CR (days 1 to 6) was 48.9% versus 25.3% (P = .0002). Additionally, significantly less nausea was observed with the combination on day 1 (P = .0002), days 2 to 6 (P = .0001), and days 1 to 6 (P = .00004). Patient preference was 63.6% for the combination and 13.6% for ondansetron alone; 22.7% expressed no treatment preference (P < .0001; therapeutic gain 50.0%; 95% confidence interval [CI], 31.6% to 68.4%). Adverse reactions were mild and without significant differences between the two treatments. CONCLUSION: Metopimazine plus ondansetron was significantly superior to ondansetron alone, concerning all efficacy parameters assessed, in patients who received platinum-based chemotherapy.

Clinical protocol for pregnancy termination in bitches using prostaglandin F2 alpha.

Sixty-seven pregnant bitches were given atropine sulphate (0.025 mg kg-1), prifinium bromide (0.1 ml kg-1) and metopimazine (0.5 mg kg-1) and 15 min later 2.5 micrograms cloprostenol kg-1 s.c., three times at 48 h intervals (day 1, day 3, day 5). After one treatment, 53 of the 67 bitches had aborted, and after a second treatment, 62 of the 67 bitches had aborted. In 18 bitches, progesteronemia kinetics were followed-up: the first injection of cloprostenol resulted in a significant (P < 0.01) fall in progesteronemia. In 12 of the 18 bitches that had aborted following the first protocol, this rapid fall in progesterone was noteworthy as it decreased progesterone concentration on average from 17.07 +/- 8.20 ng ml-1 on day 1 to 1.31 +/- 0.34 ng ml-1 on day 3. The premedication administered 15 min before the injection of prostaglandins, prevented the appearance of side effects in 39 of the 67 bitches (58.2%).

Clinical application of nebulized opioids for treatment of dyspnoea in patients with malignant disease.

This article describes our experience in the clinical use of nebulized opioids for the management of dyspnoea in patients with terminal cancer by reviewing three specific patient case studies in which this treatment was found to be both safe and effective in controlling breathlessness. The patients were treated with morphine, hydromorphone or anileridine in various doses according to their prior use of opioids. Additional formal studies are being initiated at this Centre.

Ondansetron plus metopimazine compared with ondansetron alone in patients receiving moderately emetogenic chemotherapy.

BACKGROUND AND METHODS: The serotonin (5-hydroxytryptamine3) antagonists have improved the treatment of acute chemotherapy-induced nausea and vomiting, but their ability to prevent delayed nausea and vomiting seems less pronounced. The results of a preliminary open trial suggested that the addition of a selective dopamine D2 antagonist could improve the antiemetic efficacy of the serotonin antagonists. In a randomized, double-blind, crossover trial, we compared oral treatment with ondansetron (8 mg twice a day) and the dopamine D2 antagonist metopimazine (30 mg four times a day) with treatment with ondansetron alone for three days in 30 patients who had vomited during the previous cycle of chemotherapy. All the patients received moderately emetogenic chemotherapy. RESULTS: Combination treatment with ondansetron and metopimazine significantly reduced the incidence of acute (P = 0.006) and delayed (P = 0.02) nausea and acute (P = 0.02) and delayed (P = 0.006) vomiting, as compared with treatment with ondansetron alone. Patients had significantly fewer days of nausea (P = 0.03) and vomiting (P = 0.003) if they received combination therapy. Sixty-seven percent of the patients preferred ondansetron and metopimazine, and 33 percent favored ondansetron alone (P = 0.10). Adverse reactions were mild with both regimens. With the exception of constipation, which was reported more frequently with combination therapy (P = 0.03), there were no significant differences in adverse reactions. CONCLUSIONS: Ondansetron plus metopimazine is a highly effective and safe antiemetic regimen that is markedly superior to treatment with ondansetron alone in patients receiving moderately emetogenic chemotherapy.

Idaverine, an M2- vs. M3-selective muscarinic antagonist, does not prevent motion sickness in cats.

In this study, the affinity profile of idaverine for the M1- (neuronal tissue), M2- (heart) and M3- (glandular tissue/nonvascular smooth muscle) muscarinic receptors was examined by means of radioligand binding and in vitro organ bath experiments in order to use the compound for the investigation of the muscarinic receptor subtype involved in motion sickness. In the profile study a comparison was made with the muscarinic antagonists atropine, pirenzepine (M1-selective) AF-DX 116 (M2-selective) and 4-DAMP (high affinity for M1- and M3-binding sites). The affinity of idaverine appeared to be equally high for the M1- and M2-binding sites. However, the affinity for the M1-binding sites should be interpreted cautiously since the Hill slope deviated from unity. Idaverine showed a 20-fold selectivity for the M2-binding sites over the M3-binding sites, whereas it showed a small selectivity (less than 5-fold) for the M2-receptors compared to the ileal and tracheal smooth muscle receptors. Thus idaverine appears to be M2 over M3 selective. However, in contrast to AF-DX 116, it is not clear whether idaverine is also M2 over M1 selective. In experiments with cats, idaverine failed to prevent motion sickness at doses from 0.03 to 3 mg/kg. These results are interpreted to implicate M3-receptors in the motion sickness suppressant effect of antimuscarinic drugs.