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The pharmacokinetics of maropitant were evaluated in beagle dogs dosed orally with Cerenia® tablets ( Pfizer Animal Health) once daily for 14 consecutive days at either 2 mg/kg or 8 mg/kg bodyweight. Noncompartmental pharmacokinetic analysis was performed on the plasma concentration data to measure the AUC0-24 (after first and last doses), Ct (trough concentration-measured 24 h after each dose), Cmax (after first and last doses), tmax (after first and last doses), λz (terminal disposition rate constant; after last dose), t1/2 (after last dose), and CL/F (oral clearance; after last dose). Maropitant accumulation in plasma was substantially greater after fourteen daily 8 mg/kg doses than after fourteen daily 2 mg/kg doses as reflected in the AUC0-24 accumulation ratio of 4.81 at 8 mg/kg and 2.46 at 2 mg/kg. This is most likely due to previously identified nonlinear pharmacokinetics of maropitant in which high doses (8 mg/kg) saturate the metabolic clearance mechanisms and delay drug elimination. To determine the time to reach steady-state maropitant plasma levels, a nonlinear model was fit to the least squares ( LS) means maropitant Ct values for each treatment group. Based on this model, 90% of steady-state was determined to occur at approximately four doses for daily 2 mg/kg oral dosing and eight doses for daily 8 mg/kg oral dosing. [ABSTRACT FROM AUTHOR]

Cox, S.R., Lesman, S.P., Boucher, J.F., Krautmann, M.J., Hummel, B.D., Savides, M., Marsh, S., Fielder, A., Stegemann, M.R. The pharmacokinetics of mavacoxib, a long-acting COX-2 inhibitor, in young adult laboratory dogs. J. vet. Pharmacol. Therap. 33, 461-470. The pharmacokinetics of mavacoxib were evaluated in an absolute bioavailability study, a dose-proportionality study and a multi-dose study in young healthy adult laboratory Beagle dogs and in a multi-dose safety study in Beagle-sized laboratory Mongrel dogs. When administered as the commercial tablet formulation at 4 mg/kg body weight (bw) to fasted dogs, the absolute bioavailability (F) of mavacoxib was 46.1%; F increased to 87.4% when mavacoxib was administered with food. Following intravenous administration, the total body plasma clearance of mavacoxib was 2.7 mL·h/kg, and the apparent volume of distribution at steady-state was 1.6 L/kg. The plasma protein binding of mavacoxib was approximately 98% in various in vitro and ex vivo studies. The dose-normalized area under the plasma concentration-time curve was similar in Beagle and Beagle-sized Mongrel dogs when mavacoxib was administered with food. Mavacoxib exhibited dose-proportional pharmacokinetics for single oral doses of 2-12 mg/kg in Beagle dogs and for multiple oral doses of 5-25 mg/kg in Beagle-sized Mongrel dogs. Only minor accumulation occurred when mavacoxib was administered at doses of 2-25 mg/kg bw orally to laboratory dogs with a 2-week interval between the 1st two doses but with a monthly interval thereafter. Across all three Beagle studies ( n = 63) the median terminal elimination half-life ( t½) was 16.6 days, with individual values ranging 7.9-38.8 days. The prolonged t½ for mavacoxib supports the approved regimen in which doses are separated by 2-4 weeks. [ABSTRACT FROM AUTHOR]

Maropitant (Cerenia™), a selective neurokinin1 receptor antagonist, was evaluated for safety and efficacy in treatment and prevention of acute vomiting due to various etiologies in dogs in a randomized clinical trial. Two-hundred seventy-eight dogs were enrolled from 29 veterinary hospitals. Two-hundred fifty-two were evaluable for efficacy, while 275 were evaluable for safety. A randomized block design was utilized (three maropitant- and one placebo-treated dog per block). Initial treatment was maropitant at 1 mg/kg body weight (0.45 mg/lb) or an equivalent volume of saline (placebo) administered subcutaneously. On the subsequent 1 to 4 days, maropitant or placebo (dependent on allocation) was administered subcutaneously or orally at approximate 24-h intervals as needed. Oral doses were administered as maropitant tablets using unit dosing to deliver a minimum dose of 2 mg/kg body weight (0.9 mg/lb) or equivalent numbers of similar placebo tablets. Dogs and housing were observed twice daily for evidence of vomiting. Emesis was significantly ( P ≤ 0.0012) reduced in maropitant-treated dogs as 50% (32/64) of placebo-treated dogs continued to vomit compared to only 21.8% (41/188) of maropitant-treated dogs. Post-treatment clinical signs were consistent with clinical diagnoses and judged not to be treatment related. In this clinical trial, maropitant was safe and effective in reducing emesis due to various etiologies in dogs. [ABSTRACT FROM AUTHOR]

Maropitant (Cerenia™; a novel, selective neurokinin1 receptor antagonist), chlorpromazine, metoclopramide and ondansetron were compared in two randomized, placebo-controlled studies for efficacy in preventing emesis induced by emetogens acting centrally (apomorphine; Study 1) or peripherally (syrup of ipecac; Study 2) in dogs. In each study, ten male and ten female beagles were treated in a five-treatment, five-period crossover design. The five treatments were 0.9% saline (0.1 mL/kg), maropitant (1 mg/kg), metoclopramide (0.5 mg/kg), or chlorpromazine (0.5 mg/kg) all administered subcutaneously, or ondansetron (0.5 mg/kg) administered intravenously. One hour posttreatment dogs were challenged with apomorphine at 0.1 mg/kg intravenously (Study 1) or syrup of ipecac at 0.5 mL/kg orally (Study 2). Following emetogen challenge, dogs were observed for 30 min (Study 1) or 1 h (Study 2) for emesis. No clinical signs, other than those related to emesis, were observed. Efficacy of maropitant in preventing emesis induced centrally by apomorphine was not different ( P > 0.05) from metoclopramide or chlorpromazine but was superior ( P < 0.0001) to ondansetron. Efficacy of maropitant in preventing emesis induced by syrup of ipecac was not different ( P > 0.05) from ondansetron but was superior ( P ≤ 0.0102) to metoclopramide or chlorpromazine. Maropitant was effective ( P < 0.0001 relative to control) in preventing vomiting caused by stimulation of either central or peripheral emetic pathways, whereas the other drugs examined prevented vomiting caused by central (metoclopramide and chlorpromazine; P < 0.0001) or peripheral (ondansetron; P < 0.0001) stimulation but not both. [ABSTRACT FROM AUTHOR]

Maropitant (CereniaTM), a selective neurokinin1 receptor antagonist, was evaluated for efficacy and safety in prevention of vomiting due to motion sickness in dogs in two randomized clinical trials. One-hundred eighty-nine dogs with a history of motion sickness were enrolled at 26 veterinary clinics (across 12 US states) across the two trials; of these, 163 were fully evaluable, 19 were evaluable only for safety, and seven were not evaluable. Each trial used a two-period crossover design. Each dog was treated orally with placebo or maropitant (minimum dose of 8 mg/kg body weight using unit dosing) tablets at approximately 2 h (Trial 1) or 10 h (Trial 2) before an automobile ride of approximately 60 min, during which dogs were observed for signs of motion sickness. Following a 10–14-day washout period, each dog was administered the opposite treatment and taken for another journey (same route, driver and vehicle). Maropitant reduced the occurrence of vomiting compared to placebo by 86.1% or 76.5% when given approximately 2 or 10 h prior to travel, respectively. No significant clinical signs were observed after maropitant treatment. Maropitant was safe and effective in preventing vomiting due to motion sickness in dogs when administered at a minimum dose of 8 mg/kg body weight as oral tablets 2 or 10 h prior to travel. [ABSTRACT FROM AUTHOR]

Chemotherapy-induced nausea and vomiting (CINV) is a common side-effect of cisplatin therapy. Maropitant (Cerenia™), a novel neurokinin-1 receptor antagonist, was evaluated for prevention and treatment of cisplatin-induced emesis in tumour-bearing dogs. Dogs ( n= 122) were randomly allocated to three treatment groups: T01, placebo before and after cisplatin; T02, placebo before and maropitant after cisplatin; or T03, maropitant before and placebo after cisplatin. Maropitant treatment (T02) following a cisplatin-induced-emetic event resulted in significantly fewer subsequent emetic events ( P= 0.0005) than in placebo-treated dogs (T01). In placebo-treated (T01) dogs, 56.4% were withdrawn from the study because of treatment failure compared with 5.3% in group T02. When maropitant was administered prior to cisplatin treatment (T03) in a prevention regime, 94.9% did not vomit compared with only 4.9% of placebo-treated dogs, and significantly fewer emetic events ( P < 0.0001) were observed in those dogs that did vomit. In summary, maropitant was safe and highly effective in reducing or completely preventing cisplatin-induced emesis. [ABSTRACT FROM AUTHOR]