The anti-emetic efficacy of maropitant (Cerenia?) in the treatment of ongoing emesis caused by a wide range of underlying clinical aetiologies in canine patients in Europe

Cardiorespiratory Effects and Desflurane Requirement in Dogs Undergoing Ovariectomy after Administration Maropitant or Methadone

General anesthesia for ovariectomy in dogs is based on a balanced anesthesia protocol such as using analgesics along with an inhalant agent. While opioids such as fentanyl and methadone are commonly used for their analgesic potency, other drugs can also have analgesic effects. Maropitant, an antiemetic for dogs and cats, has also been shown to exert analgesic effects, especially on visceral pain. The aim of this study was to compare the cardiorespiratory effects and analgesic properties of maropitant and methadone combined with desflurane in dogs undergoing ovariectomy. Two groups of 20 healthy mixed-breeds bitches undergoing elective ovariectomy received intravenous either maropitant at antiemetic dose of 1 mg kg^-1 or methadone at the dose of 0.3 mg kg^-1. Cardiorespiratory variables were collected before premedication, 10 min after sedation and during surgery. Recovery quality and postoperative pain were evaluated 15, 30, 60, 120, 240 and 360 min postoperatively. Results showed that maropitant produced analgesia and reduced the requirement of desflurane in amounts similar to those determined by methadone (5.39 ± 0.20% and 4.91 ± 0.26%, respectively) without significant difference, while maintaining heart rate, arterial blood pressure, respiratory rate and carbon dioxide end-tidal partial pressure even at a more satisfactory level. Therefore, maropitant may be recommended as an analgesic drug for abdominal surgery not only in healthy dogs but also in those with reduced cardiorespiratory compensatory capacities or at risk of hypotension, especially when combined with a sedative such as dexmedetomidine.

Pharmacokinetics of maropitant citrate in Rhode Island Red chickens (Gallus gallus domesticus) following subcutaneous administration

Maropitant citrate is a synthetic neurokinin‐1 receptor antagonist and substance P inhibitor used for control of emesis in dogs in cats. Maropitant citrate is used empirically in birds, despite a lack of pharmacokinetic data in avian species. The objective of this study was to determine the pharmacokinetic profile of a single dose of maropitant citrate 1 and 2 mg/kg subcutaneously (SC) in eight Rhode Island Red hens (Gallus gallus domesticus). A crossover study design was used with 1‐week washout between trials. Blood samples were collected over 36 h after drug administration. Plasma concentrations were measured using liquid chromatography–tandem mass spectrometry and pharmacokinetic parameters were determined via non‐compartmental analysis. The mean maximum plasma concentration, time to maximum concentration, and elimination half‐life following 1 and 2 mg/kg SC were 915.6 ± 312.8 ng/ml and 1195.2 ± 320.2 ng/ml, 0.49 ± 0.21 h and 1.6 ± 2.6 h, and 8.47 ± 2.24 h and 8.58 ± 2.6 h, respectively. Pharmacokinetic data suggests doses of 1 or 2 mg/kg SC may be administered every 12–24 h to maintain above target plasma concentration similar to dogs (90 ng/ml). These data provide a basis for further investigation of maropitant citrate pharmacokinetics and pharmacodynamics in birds.

Drug-Dosing Adjustment in Dogs and Cats with Chronic Kidney Disease

Chronic kidney disease is a common kidney disorder in adult and aged dogs and cats; the management of associated complications and comorbidities generally requires a life-long medical treatment to ensure a good quality of life of affected patients. However, indications and the literature on drug dosing in dogs and cats with chronic kidney disease are often lacking. The aim of this review is to revise the current literature on drug dosing in canine and feline patients with renal impairment, with a special focus on the most commonly used medications to manage chronic kidney disease and possible comorbidities.

Continuous Infusion of Ketamine and Lidocaine Either with or without Maropitant as an Adjuvant Agent for Analgesia in Female Dogs Undergoing Mastectomy

Maropitant, an antagonist of neurokinin-1 (NK-1) receptors, blocks the pharmacological action of substance P on the central and peripheral nervous systems. The objective of this study was to compare the antinociceptive and cardiorespiratory effects of the continuous intraoperative infusion of maropitant with ketamine and lidocaine in female dogs undergoing unilateral radical mastectomy. Twenty-four female dogs were used and were divided randomly into two groups (n = 12). The GLK group received ketamine bolus (1.0 mg/kg), lidocaine bolus (1.5 mg/kg), and continuous infusion of ketamine and lidocaine (10 mcg/kg/min and 50 mcg/kg/min), respectively; the GLKM group received the same anesthetic protocol combined with maropitant bolus (1.5 mg/kg/IV) and continuous infusion of maropitant (100 mcg/kg/h). Continuous infusion was initiated at the start of surgery and was maintained until 1 hour postoperatively. Pain was evaluated in the postoperative period using four scales and a digital analgesimeter. Data were analysed using analysis of variance, Student's t-test, Mann–Whitney test, and Friedman's test (P < 0.05). Kaplan–Meier curves were compared using the log-rank test. The results indicated lower pain scores, better survival curves with a lower number of patients requiring rescue analgesia, and lower peripheral sensitization, in the GLKM group than in the GLK group. It was concluded that the coadministration of maropitant with ketamine and lidocaine had an adjuvant effect with minimal cardiorespiratory effects and effective analgesia, improving pain management and patient comfort.

Effect of combinations of morphine, dexmedetomidine and maropitant on the electroencephalogram in response to acute electrical stimulation in anaesthetized dogs

This study was conducted to compare the efficacy of combinations of morphine, dexmedetomidine and maropitant in preventing the changes in electroencephalographic (EEG) indices of nociception in anaesthetized dogs subjected to a noxious electrical stimulus. In a crossover study, eight healthy adult dogs were randomly allocated to four groups: Mor: morphine 0.6 mg/kg; Dex + Mor: morphine 0.3 mg/kg + dexmedetomidine 5 μg/kg; Maro + Mor: morphine 0.3 mg/kg + maropitant 1 mg/kg; and Dex + Maro + Mor: morphine 0.2 mg/kg + dexmedetomidine 3 μg/kg + maropitant 0.7 mg/kg. Following intramuscular administration of test drugs in a minimal anaesthesia model, a supramaximal electrical stimulus (50 V at 50 Hz for 2 s) was applied and the EEG data were recorded. There were significant increases (p < .05) in the poststimulus median frequency (F50) only in groups Mor and Maro + Mor. Dex + Mor group had a significantly lower change in F50 and F95 compared to all other treatment groups. There was no correlation of the changes in EEG frequencies with blood plasma concentration of the drugs during and after noxious stimulation. Combination of dexmedetomidine and morphine was most effective in abolishing the changes in EEG indices in response to a noxious stimulus indicating a supra-additive interaction between these two drugs.

Evaluation of the effectiveness of preoperative administration of maropitant citrate and metoclopramide hydrochloride in preventing postoperative clinical gastroesophageal reflux in dogs

OBJECTIVE

To investigate the prophylactic effectiveness of preoperative administration of maropitant citrate and metoclopramide hydrochloride in preventing postoperative clinical gastroesophageal reflux (GER) in dogs and to identify risk factors for clinical postoperative GER in dogs.

ANIMALS

93 client-owned dogs undergoing surgery at the Washington State University Veterinary Teaching Hospital between March 2016 and February 2017.

PROCEDURES

Dogs were randomly assigned to either the intervention group (preoperatively received maropitant and metoclopramide) or the control group (did not preoperatively receive maropitant and metoclopramide). After surgery, all dogs were recovered and monitored, and occurrences of GER were noted. The prophylactic effectiveness of maropitant and metoclopramide was evaluated, and univariate and multivariate logistic regression analyses were performed to identify variables associated with postoperative clinical GER in dogs.

RESULTS

No meaningful difference in the incidence of clinical GER during the postoperative period was detected between the control and intervention groups. Results indicated that variables associated with significantly increased odds of postoperative clinical GER included the male sex (OR, 9.2; 95% confidence interval [CI], 1.26 to 195.0), an overweight BCS (OR, 12.3; 95% CI, 2.1 to 135.1), gastrointestinal surgery (OR, 30.5; 95% CI, 3.0 to 786.9), and requirement for a dexmedetomidine constant rate infusion after surgery (OR, 9.6; 95% CI, 1.3 to 212.5).

CONCLUSIONS AND CLINICAL RELEVANCE

Findings indicated that incidence of clinical GER during the postoperative period was not lower for dogs that received preoperative prophylactic administration of metoclopramide and maropitant, compared with incidence dogs that did not receive the prophylactic treatment. Further research is required into alternative measures to prevent postoperative clinical GER in dogs.

Evaluating the anti-inflammatory and analgesic properties of maropitant: A systematic review and meta-analysis

The neurotransmitter Substance P, and its neurokinin-1 receptor (NK-1R) are involved in the regulation of many pathophysiological processes including emesis, inflammation and nociceptive processing. This review provides a brief summary of the anti-inflammatory and analgesic properties of experimental NK-1R antagonists followed by a systematic review and meta-analysis on maropitant, the only NK-1R antagonist with a label indication for emesis in veterinary patients. There is very limited evidence based information on the putative clinical utilisation of maropitant for pain and inflammation. The aim of this systematic review and meta-analysis was to evaluate published reports on anti-inflammatory, analgesic and anaesthesia-sparing effects of maropitant. Medline, Pubmed, Science direct and Web of Science were searched to identify all published studies on maropitant, followed by a meta-analysis. Fourteen studies with 128 animals receiving maropitant and 127 controls met the inclusion criteria. Overall, maropitant had a significant inhalation anaesthetic-sparing effect (SMD -0.92, 95% CI -1.30, -0.54; P < 0.00001). However, treatment with maropitant had no effect on pain (SMD 0.06, 95% CI -0.37, 0.48; P = 0.80), or leukocyte cell infiltration in different inflammatory conditions (SMD -0.60, 95% CI -1.31, 0.11; P = 0.10). Based on all eligible studies for this review, it can be deduced that maropitant significantly reduced the minimum alveolar concentrations for isoflurane and sevoflurane for many different surgical procedures but it had no clearly proven effect on inflammation and pain.

Pharmacokinetics of morphine in combination with dexmedetomidine and maropitant following intramuscular injection in dogs anaesthetized with halothane

The purpose of this study was to evaluate the pharmacokinetics of morphine in combination with dexmedetomidine and maropitant injected intramuscularly in dogs under general anaesthesia. Eight healthy dogs weighing 25.76 ± 3.16 kg and 3.87 ± 1.64 years of age were used in a crossover study. Dogs were randomly allocated to four groups: (1) morphine 0.6 mg/kg; (2) morphine 0.3 mg/kg + dexmedetomidine 5 μg/kg; (3) morphine 0.3 mg/kg + maropitant 1 mg/kg; (4) morphine 0.2 mg/kg + dexmedetomidine 3 μg/kg + maropitant 0.7 mg/kg. Blood samples were collected before, 15 and 30 min, and 1, 2, 3 4, 6 and 8 hr after injection of the test drugs. Plasma concentration of the drugs was determined by liquid chromatography-mass spectrometry. The elimination half-life (T_1/2 ) of morphine was higher and the clearance rate (CL) was lower when combined with dexmedetomidine (T_1/2  = 77.72 ± 20.27 min, CL = 119.41 ± 23.34 ml kg^-1  min^-1 ) compared to maropitant (T_1/2  = 52.73 min ± 13.823 ml kg^-1  min^-1 , CL = 178.57 ± 70.55) or morphine alone at higher doses (T_1/2  = 50.53 ± 12.55 min, CL = 187.24 ± 34.45 ml kg^-1  min^-1 ). Combining morphine with dexmedetomidine may increase the dosing interval of morphine and may have a clinical advantage.

Perspectives on Feeding and Nutrition

Many palliative care patients have reduced oral intake during their illness. Managing inadequate intake through appetite stimulation and/or artificial hydration and nutrition poses many clinical, ethical, and logistical dilemmas. This article aids the health care team in making appropriate recommendations regarding assisted nutrition and hydration for palliative care and terminal patients. It provides a decision-making framework, including an ethical approach to determining appropriate use of assisted feeding and hydration methods in pets at the end of life. It also summarizes various clinical and logistical approaches to treating decreased food/water consumption, including potential benefits and burdens, should intervention be deemed appropriate.

The anti-inflammatory action of maropitant in a mouse model of acute pancreatitis

The neurokinin 1 receptor (NK1R) plays an important role in the pathogenesis of acute pancreatitis (AP). Maropitant is an NK1R antagonist that is widely used as an antiemetic in dogs and cats. In the present study, we investigated the anti-inflammatory action of maropitant in a mouse model of AP. AP was induced in BALB/c mice by intraperitoneal administration of cerulein, and maropitant was administered subcutaneously at a dose of 8 mg/kg. We assessed the mRNA expression levels of NK1R and substance P (SP) in the pancreatic tissue via real-time reverse transcription polymerase chain reaction. In addition, the effect of maropitant on plasma amylase, lipase, and interleukin-6 (IL-6) levels was measured in each mouse. Inflammatory cell infiltration in the pancreas was assessed by myeloperoxidase (MPO) staining. Our results showed that AP induction significantly elevated the mRNA expression of SP in the pancreatic tissue. Treatment with maropitant significantly lowered plasma amylase and IL-6 levels. In addition, treatment with maropitant inhibited the infiltration of MPO-positive cells in the pancreas. The present study suggests that maropitant possesses an anti-inflammatory activity, in addition to its antiemetic action.

Substance P and the neurokinin-1 receptor expression in dog ileum with and without inflammation

In the gastrointestinal tract, the tachykinin Substance P (SP) is involved in motility, fluid and electrolyte secretion, and blood flow and regulation of immunoinflammatory response. SP exerts its biological activity on target cells by interacting mainly with the neurokinin-1 receptor (NK₁R). The present study aims to quantify the percentage of SP-immunoreactive (SP-IR) enteric neurons and the density of SP-IR nerve fibers in the ileum of control dogs (CTRL-dogs; n=7) vs dogs with spontaneous ileal inflammation (INF-dogs; n=8). In addition, the percentage of enteric neurons bearing NK₁R, and nitrergic neurons (nNOS-IR) expressing NK₁R immunoreactivity were evaluated in both groups. The percentages of SP-IR neurons were similar in CTRL- and INF-dogs, in either the myenteric (MP) (15±8% vs. 16±7%, respectively) and submucosal plexus (SMP) (26±7% vs. 24±14%, respectively). In INF-dogs, the density of SP-IR mucosal nerve fibers showed a trend to decrease (P=0.07). Myenteric neurons of CTRL- and INF-dogs expressed similar percentages of NK₁R-immunoreactivity (39±5% vs. 38±20%, respectively). Submucosal NK₁R-IR neurons were occasionally observed in a CTRL-dog. MP nitrergic neurons bearing NK₁R showed a trend to decrease in INF-dogs vs. CTRL- dogs (41±22% vs. 65±10%, respectively; P=0.11). In INF-dogs, muscle cells and immune cells overexpressed NK₁R immunoreactivity. These findings should be taken as a warning for possible intestinal motility disorders, which might occur during administration of NK₁R-antagonist drugs. Conversely, the strong expression of NK₁R immunoreactivity observed in muscle and mucosal immune cells of inflamed tissues may provide a rationale for the use of NK₁R antagonist drugs in the treatment of intestinal inflammation.

Comparative efficacy of metoclopramide, ondansetron and maropitant in preventing parvoviral enteritis-induced emesis in dogs

The aim of the study was to evaluate the efficiencies of selected anti‐emetic drugs (metoclopramide, ondansetron and maropitant) in preventing vomiting in the treatment of canine parvoviral enteritis. We designed a randomized, prospective clinical study. PVE quick ELISA test‐positive dogs between 4 and 12 months of age were included in the study. Each of metoclopramide, ondansetron, maropitant and control group had 8 dogs. Metoclopramide and ondansetron were administered as 0.5 mg/kg doses three times a day via intravenous route, and maropitant was administered as 1 mg/kg doses once a day subcutaneously. The number and severity of daily vomitings were recorded. All dogs were treated and monitored for five days; treatments were continued until all animals healed. Metoclopramide, ondansetron and maropitant decreased the severity of vomiting from the first day and the vomiting numbers from the third day in PVE treatment. Obtained results showed that maropitant can be used successfully such as metoclopramide and ondansetron, which are frequently used for PVE treatment. At the same time, it was discovered that metoclopramide, ondansetron and maropitant were equally effective in reducing the frequency and severity of vomiting.

Altered states part 2: addressing nausea in canine research subjects

Nausea and emesis can occur for multiple reasons. While research staff can readily empathize with this type of discomfort, proper assessment and treatment can be challenging. In order to provide optimal care for canine research subjects, it is critical that institutions develop a treatment plan and take preemptive measures to control nausea and emesis when they occur.

Canine parvoviral enteritis: an update on the clinical diagnosis, treatment, and prevention

Canine parvovirus type 2 is the cause of a highly contagious acute enteritis associated with high morbidity and mortality, with very low survival rates in untreated dogs. Although severe clinical disease typically occurs in dogs younger than 6 months of age, adults with insufficient immunity may potentially be affected. In this article, the current state of knowledge is reviewed regarding the diagnostic aspects of parvoviral enteritis, with special emphasis placed on the clinical relevance of the detection of viral antigens in the feces, detection of viral antibodies in the serum, or the polymerase chain reaction-based amplification of the viral DNA in the feces. In addition, the components of the supportive and symptomatic treatment aiming to optimize the outcome of the disease in the clinical setting are thoroughly reviewed. Immunization guidelines for the prevention of the disease are also updated.

Comparison of NK-1 Receptor Antagonist (Maropitant) to Morphine as a Pre-Anaesthetic Agent for Canine Ovariohysterectomy

OBJECTIVE

To compare the NK-1 receptor antagonist maropitant to morphine during and after surgery in dogs undergoing ovariohysterectomy (OHE).

METHODS

30 healthy female dogs were randomly divided to receive either a pre-anaesthetic dose of morphine (0.5 mg/kg SQ) or maropitant (1 mg/kg, SQ) prior to OHE. Anaesthesia was induced with propofol and maintained with isoflurane. Expired isoflurane concentration, heart rate (HR), systolic arterial pressure (SAP) and respiratory rate were measured. Post-operative pain scores and appetite were evaluated during the recovery period. Rescue analgesia (morphine 0.1 mg/kg IV) was administered as needed post-operatively based on blinded pain score assessments.

RESULTS

Although clinically comparable; during surgical stimulation, the maropitant group had lower HR (108±18 vs 115±24 bpm; p = 0.04), lower SAP (114±23 vs 125±23 mmHg; p = 0.003) and required slightly lower percent of isoflurane anaesthetic (1.35±0.2 vs 1.51±0.4%; p = 0.005), when compared to the morphine group. In the recovery period, the maropitant group had lower pain scores at extubation (1.7±0.7 vs 3.4±2.3; p = 0.0001) and were more likely to eat within 3 hours after extubation (64.7 vs 15.3%). However, post-operative rescue analgesia requirements were similar between groups. All other measured parameters were similar between groups. The overall difference observed between groups was small and all monitored and measured parameters were within the expected range for anesthetized dogs.

CLINICAL SIGNIFICANCE

No major differences in cardiorespiratory parameters or anaesthetic requirements were observed between maropitant and morphine when used as a pre-anesthetic agent for OHE. Further studies are necessary to fully elucidate the benefits of maropitant as a pre-anaesthetic agent for canine OHE.

Effects of maropitant, acepromazine, and electroacupuncture on vomiting associated with administration of morphine in dogs

OBJECTIVE

To evaluate effects of maropitant, acepromazine, and electroacupuncture on morphine-related signs of nausea and vomiting in dogs and assess sedative effects of the treatments.

DESIGN

Randomized controlled clinical trial.

ANIMALS

222 dogs.

PROCEDURES

Dogs received 1 of 6 treatments: injection of saline (0.9% NaCl) solution, maropitant citrate, or acepromazine maleate or electroacupuncture treatment at 1 acupoint, 5 acupoints, or a sham acupoint. Morphine was administered after 20 minutes of electroacupuncture treatment or 20 minutes after injectable treatment. Vomiting and retching events and signs of nausea and sedation were recorded.

RESULTS

Incidence of vomiting and retching was significantly lower in the maropitant (14/37 [37.8%]) group than in the saline solution (28/37 [75.7%]) and sham-acupoint electroacupuncture (32/37 [86.5%]) groups. The number of vomiting and retching events in the maropitant (21), acepromazine (38), 1-acupoint (35), and 5-acupoint (34) groups was significantly lower than in the saline solution (88) and sham-acupoint electroacupuncture (109) groups. Incidence of signs of nausea was significantly lower in the acepromazine group (3/37 [8.1%]) than in the sham-acupoint group (15/37 [40.5%]). Mean nausea scores for the saline solution, maropitant, and sham-acupoint electroacupuncture groups increased significantly after morphine administration, whereas those for the acepromazine, 1-acupoint electroacupuncture, and 5-acupoint electroacupuncture groups did not. Mean sedation scores after morphine administration were significantly higher in dogs that received acepromazine than in dogs that received saline solution, maropitant, and sham-acupoint electroacupuncture treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Maropitant treatment was associated with a lower incidence of vomiting and retching, compared with control treatments, and acepromazine and electroacupuncture appeared to prevent an increase in severity of nausea following morphine administration in dogs.

Management of acute pancreatitis in dogs: a critical appraisal with focus on feeding and analgesia

Knowledge about acute pancreatitis has increased recently in both the medical and veterinary fields. Despite this expansion of knowledge, there are very few studies on treatment interventions in naturally occurring disease in dogs. As a result, treatment recommendations are largely extrapolated from experimental rodent models or general critical care principles. General treatment principles involve replacing fluid losses, maintaining hydrostatic pressure, controlling nausea and providing pain relief. Specific interventions recently advocated in human medicine include the use of neurokinin-1 antagonists for analgesia and early interventional feeding. The premise for early feeding is to improve the health of the intestinal tract, as unhealthy enterocytes are thought to perpetuate systemic inflammation. The evidence for early interventional feeding is not supported by robust clinical trials to date, but in humans there is evidence that it reduces hospitalisation time and in dogs it is well tolerated. This article summarises the major areas of management of acute pancreatitis in dogs and examines the level of evidence for each recommendation.

Efficacy of orally administered maropitant citrate in preventing vomiting associated with hydromorphone administration in dogs

OBJECTIVE

To evaluate the effectiveness of orally administered maropitant citrate in preventing vomiting after hydromorphone hydrochloride administration in dogs.

DESIGN

Randomized, blinded, prospective clinical study.

ANIMALS

40 dogs with American Society of Anesthesiologists status of I or II, > 6 months of age, and weighing between 24 and 58.2 kg (52.8 and 128.04 lb).

PROCEDURES

Dogs were randomly selected to receive maropitant (2.0 to 4.0 mg/kg [0.9 to 1.8 mg/lb]) or placebo (lactose monohydrate) orally 2 hours prior to receiving hydromorphone (0.1 mg/kg [0.045 mg/lb], IM). A blinded observer recorded the occurrence of vomiting or signs of nausea (eg, salivation or lip-licking) during a 30-minute period after hydromorphone administration. Two-tailed Fisher exact tests were used to compare the incidences of vomiting and signs of nausea with or without vomiting between treatment groups. Results-Of the 20 dogs receiving maropitant, none vomited but 12 (60%) developed signs of nausea. Of the 20 dogs receiving placebo, 5 (25%) vomited and 11 (55%) developed signs of nausea; overall, 16 of 20 (80%) dogs in the placebo treatment group vomited or developed signs of nausea. Compared with the effects of placebo, maropitant significantly decreased the incidence of vomiting but not signs of nausea in dogs administered hydromorphone.

CONCLUSIONS AND CLINICAL RELEVANCE

Among the 40 study dogs, the incidence of vomiting associated with hydromorphone administration was 25%. Oral administration of maropitant prevented vomiting but not signs of nausea associated with hydromorphone administration in dogs.

Acute Vomiting in Cats

Practical relevance The control of nausea and vomiting in cats is important in order to prevent the development of food aversion, anorexia (with its associated complications of weight loss and dehydration), and hepatic lipidosis.

Clinical challenges There are several antiemetic drugs that are clinically effective in cats. Making a rational choice from the available options requires knowledge of the likely cause of the vomiting, and the mechanisms of action and side effects of each drug. For example, a drug such as prochlorperazine, which can cause sedation, may be a useful first-line choice in a hospitalized cat that requires mild sedation to be handled, but would be undesirable in a critically ill cat.

Audience For companion animal and feline practitioners, the vomiting cat is a common presentation.

Evidence base The guidance provided in this review draws on the findings of clinical trials in humans, experimental studies in cats, some clinical trials in cats, and clinical experience.

Emesis in dogs: a review

Emesis is a common presenting sign in small animal practice. It requires a rational approach to management that is based upon a sound understanding of pathophysiology combined with logical decision making. This review, which assesses the weight of available evidence, outlines the physiology of the vomiting reflex, causes of emesis, the consequences of emesis and the approach to clinical management of the vomiting dog. The applicability of diagnostic testing modalities and the merit of traditional approaches to management, such as dietary changes, are discussed. The role and usefulness of both traditional and novel anti-emetic drugs is examined, including in specific circumstances such as following cytotoxic drug treatment. The review also examines areas in which common clinical practice is not necessarily supported by objective evidence and, as such, highlights questions worthy of further clinical research.

Supporting the veterinary cancer patient on chemotherapy: neutropenia and gastrointestinal toxicity

The application of effective chemotherapy protocols in companion animals with sensitive tumors may result in return to a good quality of life and extended long-term survival. However, the potential for adding adverse events that impact overall quality of life in veterinary cancer patients is an important consideration. To ensure the experience is a positive one for our clients and patients alike, the practicing veterinary oncologist must ensure clients are appropriately educated as to the type and likelihood of adverse events that may occur in their companions and should plan for appropriate preventative and therapeutic protocols to manage them. Such attention to detail will help guarantee their clients' experience with medical treatment is positive and worthwhile, and will result in improvement in the well-being of their companion.

Efficacy and safety of maropitant, a selective neurokinin 1 receptor antagonist, in two randomized clinical trials for prevention of vomiting due to motion sickness in dogs

Maropitant (Cerenia), a selective neurokinin(1) 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.

Safety and efficacy of injectable and oral maropitant, a selective neurokinin 1 receptor antagonist, in a randomized clinical trial for treatment of vomiting in dogs

Maropitant (Cerenia), a selective neurokinin(1) 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 <or= 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.

The pharmacokinetics of maropitant, a novel neurokinin type-1 receptor antagonist, in dogs

Maropitant is the first NK1 receptor antagonist developed to treat and prevent emesis in dogs; it is administered by subcutaneous (s.c.) injection at 1 mg/kg, or orally (p.o.), in tablet form, at either 2 or 8 mg/kg depending on indication. The absolute bioavailability of maropitant was markedly higher (90.7%) following s.c. injection than after oral administration (23.7% at the 2 mg/kg dose and 37.0% at the 8 mg/kg dose). First-pass metabolism contributes to the low bioavailability of maropitant following oral administration. The difference in bioavailability between the two oral doses reflects the nonlinear kinetics characterizing the disposition of maropitant within the 2-8 mg/kg dose range. Systemic clearance of maropitant following intravenous (i.v.) administration was 970, 995 and 533 mL/h.kg at doses of 1, 2 and 8 mg/kg, respectively. Nonproportional kinetics were observed for p.o. administered maropitant at doses ranging from 2 to 16 mg/kg but dose proportionality was demonstrated at higher doses (20-50 mg/kg). Linearity was also demonstrated following s.c. administration at 0.5, 1 and 2 mg/kg. Maximum plasma drug concentration (Cmax) occurred 0.75 h (tmax) after s.c. administration at 1 mg/kg, and at 1.7 and 1.9 h after oral administration of 8 and 2 mg/kg doses, respectively. The apparent terminal half-life of maropitant was 7.75, 4.03 and 5.46 h after dosing at 1 mg/kg (s.c.), 2 mg/kg (p.o.) and 8 mg/kg (p.o.), respectively. Feeding status had no effect on oral bioavailability. Limited accumulation occurred following once-daily administration of maropitant for five consecutive days at 1 mg/kg (s.c.) or 2 mg/kg (p.o.). At the dose of 8 mg/kg (p.o.) once daily for two consecutive days, the mean AUC(0-24h) (second dose) was 218% that of the first dose value. Urinary recovery of maropitant and its main metabolite was minimal (<1%), thus supporting the evidence that maropitant clearance is primarily hepatic.