Bioequivalence Evaluation of Three Pediatric Oral Formulations of Bilastine in Healthy Subjects: Results from a Randomized, Open Label, Crossover Study.

BACKGROUND AND OBJECTIVE: Bilastine is a non-sedating H1 antihistamine indicated for the treatment of allergic rhinoconjunctivitis and urticaria. The aim of this trial was to assess the bioequivalence of three novel pediatric oral formulations of bilastine. METHODS: An open label, randomized, four-treatment-period, four-sequence, crossover, single-center study was conducted in 23 healthy volunteers. Each subject received four single doses of bilastine under fasting conditions: a 10-mg orodispersible tablet (DT1), a 10-mg oral solution (SOL), a 10-mg orodispersible tablet without water (DT2dry), and a 10-mg orodispersible tablet with water (DT2water, reference formulation). Blood samples were collected during 72 h with a washout period of at least 7 days. Bilastine maximum plasma concentration (Cmax) and area under the plasma concentration-time curve between 0 to t time (AUC0-t) were calculated to assess bioequivalence. Tolerability was evaluated throughout the study. RESULTS: The three oral pediatric formulations tested were bioequivalent to the reference formulation as determined by the ratio test/reference of the geometric mean and their 90% confidence intervals (between 0.80 and 1.25) for the Cmax, AUC0-t and AUC0-∞. Bilastine was well tolerated when administered indistinctly as an orodispersible tablet or as an oral solution. CONCLUSION: The three oral pediatric formulations tested were found to be bioequivalent to the reference formulation. All formulations were well tolerated. TRIAL REGISTRATION: Spanish Clinical Studies Registry (REEC) number 2014-000786-41.

Model-informed pediatric development applied to bilastine: Analysis of the clinical PK data and confirmation of the dose selected for the target population.

Bilastine is a non-sedating second-generation H1 antihistamine approved for treatment of allergic rhinoconjunctivitis (AR) and urticaria (U) in adults at the oral (p.o.) dose of 20 mg once daily (OD). Optimal attributes can be anticipated for its clinical use in pediatrics due to its favorable safety and tolerability and age-independent PD profile. The aim of this work was to characterize bilastine PK in children through population modeling of data from a limited sampling confirmatory clinical trial in children with AR or U. The objective was also to ascertain whether the proposed dose (10 mg/day) in the target pediatric subset aged 2-<12 years matches the systemic exposure seen in adults at the 20 mg/day dose. A popPK model characterizing bilastine PK behavior in children aged from 4 to <12 years treated with 10 mg oral bilastine daily was successfully developed and qualified. No relationship was found between bilastine PK and age or weight; stopping rules pre-stablished to finalize the trial, i.e., model completeness and no dependence of exposure on decreasing age, were thus fulfilled. On a second step, the popPK model in children was linked to the PD model in adults assuming the same PD as described in adults and used to compare the PD outcome between both populations. Finally, an allometric scaling method and a physiological approximation were used to evaluate the suitability of the selected dose in the youngest children, showing that children from 2 years were deemed to belong to the same population as well. The achievement of comparable PK (i.e., within the range) to that observed in adults after the therapeutic dose of 20 mg, together with the achievement of similar PD and additional integrative analysis, served to confirm the validity of the 10 mg daily dose for the target pediatric subset (2 to <12 years).

Bilastine in allergic rhinoconjunctivitis and urticaria: a practical approach to treatment decisions based on queries received by the medical information department.

BACKGROUND: Bilastine is a safe and effective commonly prescribed non-sedating H1-antihistamine approved for symptomatic treatment in patients with allergic disorders such as rhinoconjunctivitis and urticaria. It was evaluated in many patients throughout the clinical development required for its approval, but clinical trials generally exclude many patients who will benefit in everyday clinical practice (especially those with coexisting diseases and/or being treated with concomitant drugs). Following its introduction into clinical practice, the Medical Information Specialists at Faes Farma have received many practical queries regarding the optimal use of bilastine in different circumstances. DATA SOURCES AND METHODS: Queries received by the Medical Information Department and the responses provided to senders of these queries. RESULTS: The most frequent questions received by the Medical Information Department included the potential for drug-drug interactions with bilastine and commonly used agents such as anticoagulants (including the novel oral anticoagulants), antiretrovirals, antituberculosis regimens, corticosteroids, digoxin, oral contraceptives, and proton pump inhibitors. Most of these medicines are not usually allowed in clinical trials, and so advice needs to be based upon the pharmacological profiles of the drugs involved and expert opinion. The pharmacokinetic profile of bilastine appears favourable since it undergoes negligible metabolism and is almost exclusively eliminated via renal excretion, and it neither induces nor inhibits the activity of several isoenzymes from the CYP 450 system. Consequently, bilastine does not interact with cytochrome metabolic pathways. Other queries involved specific patient groups such as subjects with renal impairment, women who are breastfeeding or who are trying to become pregnant, and patients with other concomitant diseases. Interestingly, several questions related to topics that are well covered in the Summary of Product Characteristics (SmPC), which suggests that this resource is not being well used. CONCLUSIONS: Overall, this analysis highlights gaps in our knowledge regarding the optimal use of bilastine. Expert opinion based upon an understanding of the science can help in the decision-making, but more research is needed to provide evidence-based answers in certain circumstances.

Comparative efficacy of bilastine, desloratadine and rupatadine in the suppression of wheal and flare response induced by intradermal histamine in healthy volunteers.

OBJECTIVE: To compare the peripheral antihistaminic activity of bilastine, rupatadine and desloratadine in inhibiting the histamine-induced wheal and flare (W&F) response. RESEARCH DESIGN AND METHODS: Twenty-four healthy volunteers aged 18-40 years participated in this crossover, randomized, double-blind, placebo-controlled clinical study. Subjects received single doses of bilastine 20 mg, desloratadine 5 mg, rupatadine 10 mg and placebo. W&F responses induced by intradermal injection of histamine 5 µg were evaluated before treatment (basal value) and at 0.5, 1, 2, 4, 6, 9, 12 and 24 hours after treatment. Fifteen minutes after histamine injection, W&F surface areas (cm2) were quantified using the Visitrak System. Itching sensation was evaluated using a 100 mm visual analog scale. EudraCT number: 2015-000790-13. MAIN OUTCOME MEASURES: The primary outcome measure was the percentage reduction in W&F areas after each active treatment compared with corresponding basal values. RESULTS: Bilastine induced the greatest inhibition in wheal area and was significantly superior to desloratadine and rupatadine from 1 to 12 hours (both p < .001). Rupatadine and desloratadine were better than placebo without differences between them. Maximum wheal inhibition occurred at 6 hours (bilastine 83%, desloratadine 38%, rupatadine 37%). Onset of action was 1 hour for bilastine and 4 hours for desloratadine and rupatadine. Bilastine was significantly superior to desloratadine and rupatadine for flare inhibition from 1-24 hours (both p < .001) with an onset of action at 30 minutes. Bilastine was significantly better than desloratadine (2-12 hours; at least p < .05) and rupatadine (2-9 hours; at least p < .01) for reducing itching sensation. Neither desloratadine nor rupatadine significantly reduced itching compared to placebo. All active treatments were well tolerated. CONCLUSIONS: Bilastine 20 mg induced significantly greater inhibition of the W&F response compared with desloratadine 5 mg and rupatadine 10 mg throughout the 24 hour study period, and had the fastest onset of action. Only bilastine significantly reduced itching sensation versus placebo.

Cognitive Performance Effects of Bilastine 20 mg During 6 Hours at 8000 ft Cabin Altitude.

INTRODUCTION: Bilastine is a new oral, second generation antihistamine used in the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. It is considered a nonsedating antihistamine and might be recommended for use in pilots, pending research on the effects on flying-related performance under hypobaric conditions that prevail in an airliner. We assessed the effects of a single dose of bilastine 20 mg on alertness and complex task performance of healthy volunteers in a hypobaric chamber at 75.2 kPa (8000 ft/2438 m cabin altitude). METHODS: In a randomized, double-blind, crossover study, 24 volunteers received a single dose of bilastine 20 mg, hydroxyzine 50 mg (active control), and placebo. Using the Vigilance and Tracking Task, Multi-Attribute Task Battery, and Stanford Sleepiness Scale, assessments were made before and up to 6 h after intake of the study medication. RESULTS: Bilastine 20 mg had no impairing effects on sleepiness levels, vigilance, or complex task performance for up to 6 h post-dose. Hydroxyzine 50 mg (active control) was associated with significant sleepiness and impaired performance across this time period, confirming the sensitivity of the tests. CONCLUSION: Bilastine 20 mg did not cause sleepiness or impaired performance on tasks related to flying. It is anticipated that a single dose of bilastine 20 mg will not affect flying performance. Bilastine may provide a safe therapeutic alternative for pilots suffering from allergic rhinitis or urticaria. Our findings might also have implications for the treatment of allergic disorders of personnel involved in other safety-sensitive jobs. Valk PJL, Simons R, Jetten AM, Valiente R, Labeaga L. Cognitive performance effects of bilastine 20 mg during 6 hours at 8000 ft cabin altitude. Aerosp Med Hum Perform. 2016; 87(7):622-627.

Safety and tolerability of bilastine 10 mg administered for 12 weeks in children with allergic diseases.

BACKGROUND: Regulations on medicinal products for paediatric use require that pharmacokinetics and safety be characterized specifically in the paediatric population. A previous study established that a 10-mg dose of bilastine in children aged 2 to <12 years provided an equivalent systemic exposure as 20 mg in adults. The current study assessed the safety and tolerability of bilastine 10 mg in children with allergic rhinoconjunctivitis and chronic urticaria. METHODS: In this phase III, multicentre, double-blind study, children were randomized to once-daily treatment with bilastine 10-mg oral dispersible table (n = 260) or placebo (n = 249) for 12 weeks. Safety evaluations included treatment-emergent adverse events (TEAEs), laboratory tests, cardiac safety (ECG recordings) and somnolence/sedation using the Pediatric Sleep Questionnaire (PSQ). RESULTS: The primary hypothesis of non-inferiority between bilastine 10 mg and placebo was demonstrated on the basis of a near-equivalent proportion of children in each treatment arm without TEAEs during 12 weeks' treatment (31.5 vs. 32.5%). No clinically relevant differences between bilastine 10 mg and placebo were observed from baseline to study end for TEAEs or related TEAEs, ECG parameters and PSQ scores. The majority of TEAEs were mild or moderate in intensity. TEAEs led to discontinuation of two patients treated with bilastine 10 mg and one patient treated with placebo. CONCLUSIONS: Bilastine 10 mg had a safety and tolerability profile similar to that of placebo in children aged 2 to <12 years with allergic rhinoconjunctivitis or chronic urticaria.

Bilastine: a new antihistamine with an optimal benefit-to-risk ratio for safety during driving.

INTRODUCTION: Rational selection of a second-generation H1-antihistamine requires efficacy and safety considerations, particularly regarding central nervous system (CNS) effects (cognitive and psychomotor function), potential for driving impairment, minimal sedative effects and a lack of interactions. This review evaluates the key safety features of the non-sedating antihistamine, bilastine, during driving and in preventing road traffic accidents. AREAS COVERED: Among the second-generation H1-antihistamines, sedative effects which can affect cognitive and psychomotor performance, and possibly driving ability, may not be similar. Bilastine is absorbed rapidly, undergoes no hepatic metabolism or cytochrome P450 interaction (minimal drug-drug interaction potential), and is a substrate for P-glycoprotein (limiting CNS entry). Positron emission tomography showed that, compared with other second-generation H1-antihistamines, bilastine has the lowest cerebral histamine H1-receptor occupancy. Bilastine 20 mg once daily (therapeutic dose) is non-sedating, does not enhance the effects of alcohol or CNS sedatives, does not impair driving performance and has at least similar efficacy as other second-generation H1-antihistamines in the treatment of allergic rhinoconjunctivitis and urticaria. EXPERT OPINION: Current evidence shows that bilastine has an optimal benefit-to-risk ratio, meeting all conditions for contributing to safety in drivers who need antihistamines, and hence for being considered as an antihistamine of choice for drivers.

Bilastine vs. hydroxyzine: occupation of brain histamine H1 -receptors evaluated by positron emission tomography in healthy volunteers.

AIM: A close correlation exists between positron emission tomography (PET)-determined histamine H1 -receptor occupancy (H1 RO) and the incidence of sedation. Antihistamines with H1 RO <20% are classified as non-sedating. The objective was to compare the H1 RO of bilastine, a second generation antihistamine, with that of hydroxyzine. METHODS: This randomized, double-blind, crossover study used PET imaging with [(11) C]-doxepin to evaluate H1 RO in 12 healthy males (mean age 26.2 years), after single oral administration of bilastine (20 mg), hydroxyzine (25 mg) or placebo. Binding potentials and H1 ROs were calculated in five cerebral cortex regions of interest: frontal, occipital, parietal, temporal, insula. Plasma bilastine concentrations, subjective sedation (visual analogue scale), objective psychomotor performance (digital symbol substitution test), physiological variables and safety (adverse events, AEs), were also evaluated. RESULTS: The mean binding potential of all five regions of interest (total binding potential) was significantly greater with bilastine than hydroxyzine (mean value 0.26 vs. 0.13, P < 0.01; mean difference and 95% CI -0.130 [-0.155, 0.105]). There was no significant difference between bilastine and placebo. Overall H1 RO by bilastine was significantly lower than that by hydroxyzine (mean value -3.92% vs. 53.95%, P < 0.01; mean difference and 95% CI 57.870% [42.664%, 73.075%]). There was no significant linear relationship between individual bilastine plasma concentrations and total binding potential values. No significant between-treatment differences were observed for sedation and psychomotor performance. Twenty-six non-serious AEs were reported. Sleepiness or sedation was not reported with bilastine but appeared in some subjects with hydroxyzine. CONCLUSIONS: A single oral dose of bilastine 20 mg had minimal H1 RO, was not associated with subjective sedation or objective impairment of psychomotor performance and was devoid of treatment-related sedative AEs, thus satisfying relevant subjective, objective and PET criteria as a non-sedating antihistamine.

Psychomotor and subjective effects of bilastine, hydroxyzine, and cetirizine, in combination with alcohol: a randomized, double-blind, crossover, and positive-controlled and placebo-controlled Phase I clinical trials.

OBJECTIVE: The aim of this study was to compare the effects of concomitant administration of alcohol and bilastine versus alcohol alone on the central nervous system. METHODS: Twenty-four healthy young volunteers of both sexes participated in a randomized, double-blind, double-dummy, crossover, and positive-controlled and placebo-controlled clinical trials. At 1-week intervals, subjects received six different treatments: (i) placebo; (ii) alcohol 0.8 g/kg alone (ALC); (iii) ALC in combination with: bilastine 20 mg (B20 + A); (iv) bilastine 80 mg (B80 + A); (v) cetirizine 10 mg (CET + A); and (vi) hydroxyzine 25 mg (HYD + A). Psychomotor performance tests (fine motor, finger tapping, nystagmus, critical flicker-fusion frequency, temporal estimation, 'd2' cancellation, and simple reaction time) and subjective self-reports (drunkenness, drowsiness, mental slowness, clumsiness, anger, attentiveness, competence, happiness, hostility, interest, and extroversion) were carried out at baseline and multiple points thereafter. RESULTS: All active treatments induced a significant psychomotor impairment. The greatest and most lasting impairment was observed with HYD + A followed by B80 + A and CET + A. In contrast, objective measures showed less impairment with B20 + A and ALC, both with a similar magnitude. Self-reports showed a subjective perception of performance impairment in all active treatments. CONCLUSION: Concomitant administration of bilastine (at therapeutic dose) and alcohol does not produce greater central nervous system depressant effects than ACL alone.

Lack of significant effect of bilastine administered at therapeutic and supratherapeutic doses and concomitantly with ketoconazole on ventricular repolarization: results of a thorough QT study (TQTS) with QT-concentration analysis.

The effect of bilastine on cardiac repolarization was studied in 30 healthy participants during a multiple-dose, triple-dummy, crossover, thorough QT study that included 5 arms: placebo, active control (400 mg moxifloxacin), bilastine at therapeutic and supratherapeutic doses (20 mg and 100 mg once daily, respectively), and bilastine 20 mg administered with ketoconazole 400 mg. Time-matched, triplicate electrocardiograms (ECGs) were recorded with 13 time points extracted predose and 16 extracted over 72 hours post day 4 dosing. Four QT/RR corrections were implemented: QTcB; QTcF; a linear individual correction (QTcNi), the primary correction; and a nonlinear one (QTcNnl). Moxifloxacin was associated with a significant increase in QTcNi at all time points between 1 and 12 hours, inclusively. Bilastine administration at 20 mg and 100 mg had no clinically significant impact on QTc (maximum increase in QTcNi, 5.02 ms; upper confidence limit [UCL] of the 1-sided, 95% confidence interval, 7.87 ms). Concomitant administration of ketoconazole and bilastine 20 mg induced a clinically relevant increase in QTc (maximum increase in QTcNi, 9.3 ms; UCL, 12.16 ms). This result was most likely related to the cardiac effect of ketoconazole because for all time points, bilastine plasma concentrations were lower than those observed following the supratherapeutic dose.

Efficacy and safety of bilastine 20 mg compared with cetirizine 10 mg and placebo in the treatment of perennial allergic rhinitis.

OBJECTIVE: Bilastine is a non-sedating second-generation H(1) antihistamine with proven efficacy and safety in the treatment of patients with seasonal allergic rhinitis and urticaria. The objective of this study was to demonstrate the efficacy and safety of bilastine in patients with perennial allergic rhinitis (PAR). METHODS: In a multicenter, randomized, placebo-controlled, double-blind, parallel-group study, patients with symptomatic PAR (n = 650) from Argentina, Europe, and South Africa received bilastine 20 mg, cetirizine 10 mg, or placebo once daily for 4 weeks. The primary efficacy outcome was the mean area under the curve (AUC) of reflective total 6-symptom scores (rT6SS) from baseline visit to day 28 (D28). Secondary outcome measures included mean AUC of instantaneous total 6-symptom scores (iT6SS), and mean AUCs of reflective and instantaneous total 4-nasal symptom scores (T4NSS) and total 2-ocular symptom scores (T2OSS) from baseline to D28. An open-label extension phase evaluated the safety of bilastine 20 mg administered to patients (n = 513) for one year. RESULTS: In the overall population no significant differences in efficacy outcomes were found between active treatments and placebo. On account of the high placebo response in South Africa, a post-hoc analysis was conducted. This analysis demonstrated that statistically significant differences existed between active treatments and placebo in the mean AUC of rT6SS (p < 0.05) and T4NSS (p < 0.02), respectively, from baseline to D28 visit for the intent-to-treat population in patients from Europe and Argentina, whereas the difference was not statistically significant in South Africa. Whether this is related to differences in the demographic or clinical characteristics of South African patients (they had PAR for longer and reported more severe symptoms) and/or the disease management process compared with their European and Argentinean counterparts warrants further investigation. CONCLUSIONS: A post-hoc analysis indicated that bilastine and cetirizine were similarly effective and more effective than placebo during a 4-week treatment period in patients with PAR. In addition, bilastine was shown to be safe and well-tolerated over a 1-year treatment period. CLINICAL TRIAL REGISTRY NUMBER: NCT01127620.

Establishing the place in therapy of bilastine in the treatment of allergic rhinitis according to ARIA: evidence review.

BACKGROUND: The ARIA (Allergic Rhinitis and its Impact on Asthma) guidelines development group examined the properties of oral H(1)-antihistamines and made proposals about an 'optimal' drug. Several criteria should be met by oral H(1)-antihistamines in terms of their pharmacological, and clinical efficacy and safety profiles. OBJECTIVE: Bilastine, a new H(1)-antihistamine, has been approved in 28 European countries for the symptomatic treatment of allergic rhinoconjunctivitis and urticaria in adults and children older than 12 years. To determine its potential place in therapy in the treatment of allergic rhinitis, this manuscript examines whether bilastine meets the criteria defined in the European Academy of Allergy and Clinical Immunology (EAACI)/ARIA proposals for oral H(1)-antihistamines. METHODS: The optimal properties of oral H(1)-antihistamines and current ARIA recommendations for their use in allergic rhinitis are presented, as well as relevant pharmacological and clinical data for bilastine obtained from the published literature that specifically address the defined criteria. RESULTS: Bilastine is a potent inhibitor of the histamine H(1) receptor. Data from preclinical studies have confirmed its selectivity for the histamine H(1) receptor over other receptors, and demonstrated antihistaminic properties in vitro and in vivo. Bilastine does not interfere with the cytochrome P450 system and is devoid of cardiac side effects. Studies in healthy volunteers and patients have shown that bilastine does not affect driving ability, cardiac conduction or alertness. In large pivotal randomized, placebo-controlled trials (RCTs), bilastine had a favourable safety profile. Bilastine 20 mg once daily improved all nasal and ocular symptoms of allergic rhinitis with greater efficacy than placebo and comparable to that of cetirizine and desloratadine. Moreover, bilastine was shown to improve quality of life, an important outcome of RCTs in allergic diseases. There were no significant changes in laboratory tests, electrocardiograms or vital signs. A potential limitation of this assessment of bilastine is that it is a literature-based review and the findings are dependent upon the quality of the published evidence. CONCLUSIONS: Bilastine meets current EAACI/ARIA criteria for medications used in the treatment of allergic rhinitis.

Acute and subchronic effects of bilastine (20 and 40 mg) and hydroxyzine (50 mg) on actual driving performance in healthy volunteers.

Bilastine is a new second-generation H1 antagonist. Although bilastine has been demonstrated to produce little or no performance impairment in laboratory tests, it cannot be excluded that it produces impairments in real-life performance such as driving. This study aims to assess the effects of two doses of bilastine (20 and 40 mg) on actual driving after single and repeated administration. Hydroxyzine 50 mg was included as an active control. Twenty-two participants (11 females, 11 males) were tested in a placebo-controlled, randomized, double-blind, four-way cross-over design. Participants were treated with once-daily doses for eight consecutive days. On day 1 and 8 of each treatment period participants performed an actual highway driving test. The primary variable was standard deviation of lateral position (SDLP), a measure of weaving. Results demonstrated that hydroxyzine significantly increased SDLP on days 1 and 8 of treatment. Bilastine did not affect SDLP. It is concluded that hydroxyzine produces severe driving impairment after single doses and that this impairment only partly mitigates over time due to a lack of complete tolerance. Bilastine did not produce any driving impairment after single and repeated doses and can be safely used in traffic in doses up to 40 mg.

Comparison of peripheral and central effects of single and repeated oral dose administrations of bilastine, a new H1 antihistamine: a dose-range study in healthy volunteers with hydroxyzine and placebo as control treatments.

Peripheral anti-H1 and central nervous system (CNS) activities after single (day 1) and repeated (day 7) administrations of increasing doses of bilastine (BIL) were assessed in 20 healthy volunteers throughout a crossover, randomized, double-blind, placebo (PLA)-controlled study. Repeated doses of BIL 20, 40, or 80 mg and hydroxyzine 25 mg (HYD) as positive standard were administered on 7 consecutive days. Before and at several time points after drug intake, skin reactivity to the intradermal injection of histamine, objective tests of psychomotor performance, and subjective mood scales were evaluated. All active treatments led to a significant and similar reduction in the wheal reaction in relation to PLA after both the single (P < 0.001) and repeated administrations (P < 0.001). No delay was observed in the onset of its peripheral activity after the first dose of BIL as compared with HYD. No tolerance or sensitization was seen when comparing acute and repetitive assessments. Central nervous system effects showed that HYD induced the greatest psychomotor impairment (P < 0.05). Repeated HYD intake showed a lower number of significant alterations in comparison to acute administration. Bilastine 80 mg also showed some impairment (P < 0.05). Subjectively, the only active treatment that could not be differentiated from PLA was BIL 20 mg. Hydroxyzine 25 mg showed the greatest differentiation (P < 0.01). A clear dissociation between peripheral anti-H1 and CNS activity was found after BIL treatment. Significant and sustained peripheral H1-blocking effects were observed after both single and repeated administrations of the therapeutic dose of 20 mg BIL. The 40-mg dose of BIL produced subjective report of sedation, whereas unwanted objective CNS side effects were observed only with the 80-mg dose.

Effects of lerisetron, a new 5-HT3 receptor antagonist, on ipecacuanha-induced emesis in healthy volunteers.

The purpose of these studies was to evaluate the effect of lerisetron (1-phenyl-methyl-2-piperazinyl-1H-benzimidazole hydrochloride, CAS 143257-98-1, F-0930-RS2), a new 5-HT3 receptor antagonist, on ipecacuanha-induced nausea and vomiting. The ipecacuanha model of emesis has been used to test the anti-emetic activity of several different 5-HT3 antagonists and the anti-emetic doses that were effective in the ipecacuanha model have been found to correlate well with the clinically effective doses. Study 1 investigated oral doses of lerisetron from 4 mg to 40 mg. Study 2 evaluated the duration of effect of a single dose of 20 mg oral lerisetron. Study 3 evaluated intravenous doses of 18 mg and 12 mg lerisetron. In Study 1, the 40 mg dose of oral lerisetron inhibited emesis in all test subjects. The percentage of subjects who experienced an emetic episode increased as the dose of lerisetron decreased. At the lowest dose level tested five of six subjects had an emetic episode compared with four out of five in the placebo group. In Study 2, 20 mg oral lerisetron was effective up to 12 h after administration. When ipecacuanha was administered at 18 h post-dose three of seven subjects had an emetic episode and at 24 h post-dose the incidence of emesis was similar to the placebo treatment groups in the previous study. Study 3 demonstrated the effectiveness of intravenous doses of lerisetron. The 18 mg intravenous dose reduced the number of patients experiencing emetic episodes by 75% compared with placebo, doses below 12 mg i.v. were not evaluated because of the reduced efficacy of the compound at this dose level. In conclusion, lerisetron has been shown to be effective in the treatment of ipecacuanha-induced nausea and vomiting at intravenous doses of 18 mg and at oral doses of 20 mg for up to 12 hours.