Anti-nausea effects and pharmacokinetics of ondansetron, maropitant and metoclopramide in a low-dose cisplatin model of nausea and vomiting in the dog: a blinded crossover study

International Renal Interest Society best practice consensus guidelines for the diagnosis and management of acute kidney injury in cats and dogs

Acute kidney injury (AKI) is defined as an injury to the renal parenchyma, with or without a decrease in kidney function, as reflected by accumulation of uremic toxins or altered urine production (i.e., increased or decreased). AKI might result from any of several factors, including ischemia, inflammation, nephrotoxins, and infectious diseases. AKI can be community- or hospital-acquired. The latter was not previously considered a common cause for AKI in animals; however, recent evidence suggests that the prevalence of hospital-acquired AKI is increasing in veterinary medicine. This is likely due to a combination of increased recognition and awareness of AKI, as well as increased treatment intensity (e.g., ventilation and prolonged hospitalization) in some veterinary patients and increased management of geriatric veterinary patients with multiple comorbidities. Advancements in the management of AKI, including the increased availability of renal replacement therapies, have been made; however, the overall mortality of animals with AKI remains high. Despite the high prevalence of AKI and the high mortality rate, the body of evidence regarding the diagnosis and the management of AKI in veterinary medicine is very limited. Consequently, the International Renal Interest Society (IRIS) constructed a working group to provide guidelines for animals with AKI. Recommendations are based on the available literature and the clinical experience of the members of the working group and reflect consensus of opinion. Fifty statements were generated and were voted on in all aspects of AKI and explanatory text can be found either before or after each statement.

Copeptin Stimulation by Combined Intravenous Arginine and Oral LevoDopa/Carbidopa in Healthy Short Children and Children with the Polyuria-Polydipsia Syndrome

INTRODUCTION

Stimulated copeptin may provide an alternative to water deprivation testing (WDT) in the evaluation of polyuria-polydipsia syndrome (PPS). Though best studied, arginine stimulation alone produces a modest copeptin response in children. We investigated the effectiveness of the arginine + LevoDopa/Carbidopa stimulation test (ALD-ST) for copeptin.

METHODS

47 healthy short children (controls), 10 children with primary polydipsia, and 10 children with AVP deficiency received arginine hydrochloride (500 mg/kg intravenously over 30 min) and Levodopa/carbidopa (10:1 ratio; 175 mg of l-Dopa/m2 BSA) orally. Serum copeptin was measured at 0, 60, 90, and 120 min.

RESULTS

In controls, ALD-ST increased copeptin from a median of 7.0 pmol/L (IQR 5.0-10.0) to a peak of 44.0 pmol/L (IQR 21.4-181.0) between 60 and 120 min (p < 0.001). Copeptin peak was higher in subjects who experienced nausea or vomiting (57%) than in those who did not (131.0 pmol/L [IQR 42.5-193.8] vs. 22.7 pmol/L [IQR 16.0-33.7], p < 0.001). While subjects with primary polydipsia had similar baseline (8.5 pmol/L [IQR 8.0-11.0]) and stimulated (125.2 pmol/L [IQR 87.6-174.0]) copeptin levels as controls, subjects with AVP deficiency had lower baseline (2.5 pmol/L [IQR 2.0-3.1]) and peak levels (4.6 pmol/L [IQR 2.4-6.0]). A peak copeptin of ≥9.3 pmol/L best predicted absence of complete or partial AVP deficiency with a sensitivity of 100% and specificity of 80%.

CONCLUSIONS

ALD-ST induced a robust peak copeptin in healthy short children and children with primary polydipsia. Nausea/vomiting, a side effect of ALD-ST, amplified the copeptin response. The ALD-ST may be a suitable initial screening test in children with PPS.

Effect of preoperative ondansetron on postoperative nausea in healthy dogs undergoing laparoscopic gastropexy and castration

OBJECTIVE

To investigate if preoperative ondansetron reduces postoperative nausea associated with laparoscopic gastropexy and castration in dogs.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Twenty client-owned, healthy male dogs.

METHODS

Dogs were premedicated with dexmedetomidine (2-5 mcg kg-1) and methadone (0.2-0.5 mg kg-1) intramuscularly. General anesthesia was induced with propofol and maintained with an inhalant anesthetic agent. Dogs were randomized into group S (saline 0.1 mL kg-1, intravenously) or group O (ondansetron 0.2 mg kg-1, intravenously). Plasma and serum were collected before premedication and 3 hours postextubation to measure arginine vasopressin (AVP) and cortisol concentrations. Nausea scoring occurred before and 10 minutes after premedication, immediately after extubation, and at 1, 2 and 3 hours postextubation. Data were analyzed by mixed and split-plot anova with Bonferroni adjustment for the number of group comparisons. Significance was set at p < 0.05.

RESULTS

Nausea scores increased over time at 1 (p = 0.01) and 2 (p < 0.001) hours postextubation in both groups compared with before premedication. Median nausea score (0-100 mm) for groups S and O before premedication were 2.5 and 0.5 mm, respectively. At 1 and 2 hours postextubation, group S scored 7.5 and 4.0 mm and group O scored 6.0 and 5.0 mm, respectively. No significant differences in nausea scores within or between groups were observed before premedication and 3 hours postextubation. Cortisol concentrations increased significantly 3 hours postextubation in both groups (p < 0.001) compared with before premedication, with no differences between groups. AVP concentrations showed no significant differences within or between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Preoperative intravenous administration of ondansetron (0.2 mg kg-1) did not impact postoperative nausea after laparoscopic gastropexy and castration. Investigation of higher doses of ondansetron on the incidence of postoperative nausea and vomiting in dogs after surgery is warranted.

Post-treatment with maropitant reduces oxidative stress, endoplasmic reticulum stress and neuroinflammation on peripheral nerve injury in rats

OBJECTIVE

To determine the effective dose and therapeutic potential of maropitant using through expression of mediators of oxidative stress, inflammatory and of the unfolded protein response (UPR) (bio) markers on spinal cord using a model of neuropathic pain induced through chronic constriction injury (CCI) in rats.

STUDY DESIGN

Randomized, blinded, prospective experimental study.

ANIMALS

98 male Wistar rats.

METHODS

Rats were anesthetized with sevoflurane and after CCI, they were randomly assigned to the following groups that received: vehicle, 3, 6, 15, 30 e 50 mg/kg/24q of maropitant. The effect on inflammatory mediators (IL10, TNFα), oxidative stress (GPx, CAT, SOD), microglial (IBA-1) and neuronal (NeuN, TACR1) markers was evaluated though immunohistochemistry and expression levels of markers of hypoxia (HIF1α, Nrf2), antioxidant enzymes (Catalse, Sod1 and GPx1), and endoplasmic reticulum stress mediators (GRP78, CHOP and PERK) through qRT-PCR.

RESULTS

Intraperitoneal injection (IP) of maropitant inhibited nociception with ID50 values of 4,1 mg/kg (5,85-19,36) in a neuropathic pain model through CCI. A dose of 30 mg/kg/24q was significantly effective in reducing mechanical allodynia 1 to 4h after treatment with nociception inhibition (145,83%). A reduction in the expression of hypoxia factors (HIF1α, Nrf2) was observed, along with an increase in antioxidant activity (CAT, SOD and GPX). Additionally, there was a reduction in inflammatory markes (IL10, TNFα), microglial (IBA-1), and neuronal markers (NeuN, TACR1).

CONCLUSION AND CLINICAL RELEVANCE

These findings demonstrate that the determined dose, administered daily for seven days, had an antinociceptive effect, as well as anti-inflammatory and antioxidant activity.

Current definition, diagnosis, and treatment of canine and feline idiopathic vestibular syndrome

Idiopathic vestibular syndrome (IVS) is one of the most common neurological disorders in veterinary medicine. However, its diagnosis and treatment varies between publications. The aim of the current study was to gather experts' opinion about IVS definition, diagnosis, and treatment. An online-survey was used to assess neurology specialists' opinion about the definition, diagnosis and treatment of IVS. The study demonstrated that the definition, diagnosis, and treatment of IVS are largely consistent worldwide, with the EU prioritising less frequently advanced imaging and more often otoscopy to rule out other diseases. IVS was defined by most specialists as an acute to peracute, improving, non-painful peripheral vestibular disorder that often affects cats of any age and geriatric dogs. Regarding diagnosis, a detailed neurological examination and comprehensive blood tests, including thyroid values, blood pressure, and otoscopic examination, was seen as crucial. A thorough workup may also involve MRI and CSF analysis to rule out other causes of vestibular dysfunction. Treatment of IVS typically involved intravenous fluid therapy and the use of an antiemetic, with maropitant once daily being the preferred choice among specialists. Antinausea treatment was considered, however, only by a handful specialists. This survey-based study provides valuable insights from neurology experts and highlights areas that require further research to bridge the gap between theory and practice.

Antiemetic Drugs Compatibility Evaluation with Paediatric Parenteral Nutrition Admixtures

Chemotherapy-induced nausea and vomiting are defined as the most common of side effects of treatment and, at the same time, are very difficult to accept for patients', frequently causing changes in the therapy regimen, significantly reducing its effectiveness. Thus, an antiemetic prophylactic is essential to the provision of such a therapy for the patient. Pharmacotherapy often includes various drugs, including antiemetics, with the administration of such drugs by injection through two separate catheters being the preferred method. However, the co-administration of drugs and parenteral nutrition admixtures (PNAs) requires the consideration of compatibility, stability and potential negative interactions. To meet the purposes of clinical pharmacy, a compatibility test of ondansetron, dexamethasone and hydrocortisone with paediatric PNAs was conducted. PNAs differ in the composition of amino acid source (Primene® or Aminoplasmal Paed® 10%) and the type of injectable lipid emulsion (Lipidem® 200 mg/mL, Clinoleic® 20%, SMOFlipid® 200 mg/mL, Intralipid® 20%). An in vitro evaluation was performed in a static way as a simulated co-administration through a Y-site. The drug PNA ratios were determined based on the extreme infusion rates contained in the characteristics of medicinal products. All calculations were performed for a hypothetical patient aged 7 years weighing 24 kg. As a result of this study, it can be concluded that all tested PNAs showed the required stability in the range of parameters such as pH, osmolality, turbidity, zeta potential, MDD and homogeneity. The co-administration of antiemetic drugs does not adversely affect lipid emulsion stability. This combination was consistently compatible during the evaluation period.

Phylogenetic analyses of 5-hydroxytryptamine 3 (5-HT3) receptors in Metazoa

The 5-hydroxytrptamine 3 (5-HT3) receptor is a member of the 'Cys-loop' family and the only pentameric ligand gated ion channel among the serotonin receptors. 5-HT3 receptors play an important role in controlling growth, development, and behaviour in animals. Several 5-HT3 receptor antagonists are used to treat diseases (e.g., irritable bowel syndrome, nausea and emesis). Humans express five different subunits (A-E) enabling a variety of heteromeric receptors to form but all contain 5HT3A subunits. However, the information available about the 5-HT3 receptor subunit occurrence among the metazoan lineages is minimal. In the present article we searched for 5-HT3 receptor subunit homologs from different phyla in Metazoa. We identified more than 1000 5-HT3 receptor subunits in Metazoa in different phyla and undertook simultaneous phylogenetic analysis of 526 5HT3A, 358 5HT3B, 239 5HT3C, 70 5HT3D, and 173 5HT3E sequences. 5-HT3 receptor subunits were present in species belonging to 11 phyla: Annelida, Arthropoda, Chordata, Cnidaria, Echinodermata, Mollusca, Nematoda, Orthonectida, Platyhelminthes, Rotifera and Tardigrada. All subunits were most often identified in Chordata phylum which was strongly represented in searches. Using multiple sequence alignment, we investigated variations in the ligand binding region of the 5HT3A subunit protein sequences in the metazoan lineage. Several critical amino acid residues important for ligand binding (common structural features) are commonly present in species from Nematoda and Platyhelminth gut parasites through to Chordata. Collectively, this better understanding of the 5-HT3 receptor evolutionary patterns raises possibilities of future pharmacological challenges facing Metazoa including effects on parasitic and other species in ecosystems that contain 5-HT3 receptor ligands.

Comparison of radiographic scoring systems for assessment of bone healing after tibial plateau leveling osteotomy in dogs

Introduction

Accurate radiographic assessment of bone healing is vital in determining both clinical treatment and for assessing interventions aimed at the promotion of bone healing. Several scoring systems have been used to evaluate osteotomy changes following tibial plateau leveling osteotomy (TPLO). The goal of this study was to compare the ability of five radiographic scoring systems to identify changes in bone healing following TPLO over time (Aim I), and to evaluate the influence of limb positioning on TPLO osteotomy scoring (Aim II).

Materials and methods

Phase I-A randomized, blinded, prospective study was conducted using similarly positioned postoperative TPLO radiographs from seven dogs taken immediately postoperatively, 6-weeks, and 8-weeks postoperatively. Ten reviewers assessed the radiographs, and five different scoring systems were tested for each set including three previously published ones, a Visual Analog Score (VAS), and a subjective 11-point scale. For each system, responses for 6-week postoperative were compared to 8-week postoperative. Scores were judged as correct (=showing an increase in score), incorrect (=decrease in score), or unchanged (=same score). Phase II-An international group of 39 reviewers was asked to score radiographs from three dogs, taken in different positions, using the VAS grading system. Scores were averaged and comparisons were made for each set.

Results

Phase I-The VAS system identified the greatest number of sets correctly (76%), with the least unchanged scores (15%), and 9% incorrect scores. Phase II-All three patients had an increase in the average difference between VAS-scores for differently positioned radiographs compared to similarly positioned radiographs. The magnitude of change between different positions far exceeded the magnitude of comparison of the similarly positioned radiographs from the 6- and 8-week time point.

Discussion/Conclusion

The VAS system appears to be the most appropriate of the tested systems to identify small changes in bone healing. In addition, the positioning of postoperative TPLO radiographs makes a substantial difference in the healing score that is assigned. Care must be undertaken when performing postoperative radiographs in both the clinical and research setting to ensure accurate assessment of bone healing.

Pharmacokinetics and anti-nausea effects of intravenous ondansetron in hospitalized dogs exhibiting clinical signs of nausea

The purpose of this study was to evaluate the pharmacokinetics of intravenous (IV) ondansetron in a population of hospitalized dogs exhibiting clinical signs of nausea. The causes of nausea included pancreatitis, gastroenteritis, endocarditis, chemotherapy-induced nausea, diabetes mellitus and ketoacidosis, acute kidney injury with aspiration pneumonia, pyometra, uroabdomen, neoplasia, and hepatopathy. Twenty-four dogs were randomly assigned to one of the following IV ondansetron protocols: 1 mg/kg q12h, 0.5 mg/kg q12h, 1 mg/kg q8h, 0.5 mg/kg q8h. Serum was collected at 0, 0.25, 0.5, 1, 2, 4, 8, 16, and 24 h after the first dose, and nausea scores were recorded at multiple time points. Ondansetron and arginine vasopressin (AVP) concentrations were measured via high-performance liquid chromatography coupled to tandem mass spectrometry and ELISA, respectively. Noncompartmental pharmacokinetic modeling and dose interval modeling were performed. Ondansetron displayed linear pharmacokinetics. In the 0.5 mg/kg group, mean C_max  = 214 ng/ml, AUC_0-8h  = 463 ng/ml*h, and calculated half-life was 1.9 h. In the 1 mg/kg group, mean C_max  = 541 ng/ml, AUC_0-8h  = 1057 ng/ml*h and calculated half-life was 1.6 h. Serum ondansetron concentrations were not significantly different between dogs that required rescue anti-nausea medication (non-responders) and dogs that did not require rescue therapy (responders). In total, 83.3% of patients in the 0.5 mg/kg q8h, 0.5 mg/kg q12h, and 1 mg/kg q8h groups had improvement in nausea scores. In total, 66.7% of patients in the 1 mg/kg q12h group had improvement in nausea scores. In total, 33% of patients had resolution of nausea in the 0.5 mg/kg q8h, 1 mg/kg q8h, and 1 mg/kg q12h groups, and 16% of patients had resolution of nausea in the 0.5 mg/kg q12h group. AVP concentrations were highly variable and did not correlate with nausea scores. Nausea scores significantly decreased regardless of dosage protocol. AVP was not a reliable biomarker of nausea in this group of dogs.

2022 ISFM Consensus Guidelines on Management of the Inappetent Hospitalised Cat

PRACTICAL RELEVANCE

Inappetence may have many origins and, as a presenting sign or observation in the hospitalised patient, is common in feline practice. Nutritional assessment of every patient is encouraged, to identify the need for, and appropriate type of, intervention indicated. The impact of malnutrition may be significant on the feline patient, perpetuating illness, delaying recovery, slowing wound healing and negatively impacting gut health and immunity. Delayed intervention may result in the cat's deterioration; hence prompt control of contributing factors such as the underlying illness, pain, nausea, ileus and stress is vital to optimise voluntary food intake. Management is multimodal, comprising reduction of stress, medications and assisted nutrition in the form of tube feeding or parenteral nutrition. Use of antiemetic, analgesic, prokinetic and appetite stimulant medications may restore appetite, but placement of feeding tubes should not be delayed. Feeding tubes are generally well tolerated and allow provision of food, water and medication with minimal stress, although clinicians must be aware of complications such as stoma site infections and refeeding syndrome.

CLINICAL CHALLENGES

Cats are vulnerable to malnutrition owing to their unique metabolism and specific nutritional requirements. Moreover, their nature as a species means they are susceptible to stress in the hospital environment, which may result in reduced food intake; previous negative experiences may compound the problem. In particular, an inappropriate clinic environment and/or handling may cause or exacerbate inappetence in hospitalised patients, with negative impacts on recovery. Postponing interventions such as feeding tube placement to await improvement, owing to clinician or caregiver apprehension, may hinder recovery and worsen nutritional deficits.

EVIDENCE BASE

The 2022 ISFM Consensus Guidelines on Management of the Inappetent Hospitalised Cat have been created by a panel of experts brought together by the International Society of Feline Medicine (ISFM). Information is based on the available literature, expert opinion and the panel members' experience.

Evaluation of adverse events in small-breed dogs treated with maropitant and a single dose of doxorubicin

Background

The recommended doxorubicin (DOX) dose for small dogs is 1 mg/kg. Recent data suggest that DOX‐induced gastrointestinal (GI) toxicosis can be reduced with maropitant treatment.

Objectives

To investigate the incidence of adverse events (AEs) in small‐breed dogs administered a single 25 mg/m² DOX followed by administration of maropitant (DOX25). The primary aim was to assess myelo‐ and GI toxicoses for 2 weeks after DOX administration. The secondary aim was to compare the incidence and grades of AEs found in the DOX25 group with a historical control group (DOX 1 mg/kg without administration of antiemetic or antidiarrheal medications).

Animals

Nineteen small‐breed tumor‐bearing dogs.

Methods

A prospective, observational study of tumor‐bearing dogs, weighing 5 to 10 kg, administered a single 25 mg/m² dose of DOX IV, followed by administration of maropitant for the next 5 days.

Results

Inappetence, vomiting, and diarrhea were found in 7/19, 2/19, and 6/19 of the DOX25 dogs, respectively. Neutropenia and thrombocytopenia was 12/19 and 3/19, respectively. Most AEs were grades 1 and 2, except for grades 3 and 4 inappetence and neutropenia in 3 and 4 dogs, respectively. Furthermore, febrile neutropenia occurred in 3/19 dogs in the DOX25 group. All AEs between the DOX25 and historical control groups were not significantly different.

Conclusions and Clinical Importance

Vomiting and diarrhea were deemed acceptable with 25 mg/m² DOX followed by maropitant treatment in 5 to 10 kg dogs; however, additional supportive care might be needed for dogs with inappetence and neutropenia.

Prospective evaluation of complications associated with transesophageal echocardiography in dogs with congenital heart disease

Background

Transesophageal echocardiography (TEE) is useful in the assessment and procedural monitoring of congenital heart disease (CHD) with a relatively low complication rate in humans.

Objectives

To evaluate the safety of TEE and report complications in dogs.

Animals

Forty client‐owned dogs with CHD.

Methods

Prospective observational study including gastroesophagoscopy before and after TEE imaging. TEE was planned with a GE 6VT‐D adult probe in dogs weighing ≥4 kg and a GE 10T‐D microprobe alternating with an intracardiac echocardiography probe placed in the esophagus in dogs <4 kg. Difficulties with probe placement, probe interference and TEE probe imaging times were recorded. Dogs were monitored in the recovery period after TEE using an established nausea scoring system.

Results

New gastroesophageal abnormalities were identified after TEE in 4 dogs including 4 areas of mucosal damage involving <25% of the lower esophageal sphincter (n = 4) and 1 lesion at the heart base (n = 1) and were not attributed to longer imaging times or a specific probe. Lesions identified before TEE in 4 dogs remained unchanged after TEE. The 6VT‐D probe could not be placed in 1 dog with enlarged tonsils, and it obstructed fluoroscopic views in 3 dogs. The probes did not compress any structures in dogs in which fluoroscopy was performed (n = 20). Four dogs had evidence to suggest nausea after the procedure.

Conclusions and Clinical Importance

While major complications remain possible, complications in this study were mild and few in number. Dog size and probe characteristics are factors to consider when performing TEE.

2022 ISFM Consensus Guidelines on the Management of Acute Pain in Cats

PRACTICAL RELEVANCE

Increases in cat ownership worldwide mean more cats are requiring veterinary care. Illness, trauma and surgery can result in acute pain, and effective management of pain is required for optimal feline welfare (ie, physical health and mental wellbeing). Validated pain assessment tools are available and pain management plans for the individual patient should incorporate pharmacological and non-pharmacological therapy. Preventive and multimodal analgesia, including local anaesthesia, are important principles of pain management, and the choice of analgesic drugs should take into account the type, severity and duration of pain, presence of comorbidities and avoidance of adverse effects. Nursing care, environmental modifications and cat friendly handling are likewise pivotal to the pain management plan, as is a team approach, involving the cat carer.

CLINICAL CHALLENGES

Pain has traditionally been under-recognised in cats. Pain assessment tools are not widely implemented, and signs of pain in this species may be subtle. The unique challenges of feline metabolism and comorbidities may lead to undertreatment of pain and the development of peripheral and central sensitisation. Lack of availability or experience with various analgesic drugs may compromise effective pain management.

EVIDENCE BASE

These Guidelines have been created by a panel of experts and the International Society of Feline Medicine (ISFM) based on the available literature and the authors' experience. They are aimed at general practitioners to assist in the assessment, prevention and management of acute pain in feline patients, and to provide a practical guide to selection and dosing of effective analgesic agents.

Antinociceptive and analgesic effect of continuous intravenous infusion of maropitant, lidocaine and ketamine alone or in combination in cats undergoing ovariohysterectomy

Background

Multimodal analgesia consists of the combination of analgesic drugs at low doses to act in different places along the path of pain. Studies with continuous infusion of analgesic drugs in cats are not common. This study aimed to evaluate the analgesic effect of maropitant, lidocaine and ketamine alone or in combination (intravenous bolus + subsequent continuous intravenous infusion) in the management of acute postoperative pain in cats undergoing ovariohysterectomy. Seventy healthy cats undergoing an ovariohysterectomy received a standard anesthetic protocol consisting of acepromazine and morphine, propofol (anesthesia induction), and isoflurane (anesthesia maintenance). The animals were stratified into seven groups (n = 10 in each group): control (CG), maropitant (MG), lidocaine (LG), ketamine (KG), maropitant + lidocaine (LMG), maropitant + ketamine (KMG), and maropitant + lidocaine + ketamine (LKMG). All drugs were injected first as an intravenous bolus and then by continuous intravenous infusion. During surgery, esophageal temperature, respiratory rate, heart rate, oxygen saturation, expired isoflurane concentration, and partial pressure of carbon dioxide at the end of expiration were evaluated at 7 time points. Postoperative pain was evaluated for 6 h after extubation using the visual analogue scale and the UNESP-Botucatu multidimensional composite pain scale for assessing postoperative pain in cats.

Results

Adverse effects related to maropitant, lidocaine and ketamine infusion were not observed. Pain scores were lower in the MG, KG and LG groups when compared to the CG group using both scales. Although pain scores were also lower in all combination groups than CG, more animals in these groups required rescue analgesia compared to MG. This indicates that the postoperative analgesic effect of all drugs, either alone or in combination, confers analgesia, although the combinations did not promote greater analgesia.

Conclusions

Continuous intravenous infusion of maropitant, lidocaine, and ketamine alone induces postoperative analgesic effect in cats undergoing ovariohysterectomy, but combinations of these drugs did not increase the analgesic effect. No adverse effect was observed with any drug or their combination.

Investigation of binding interaction behavior between antiemetic drugs and Trypsin by spectroscopy and molecular docking

Antiemetic drugs are used to control excessive vomiting and nausea and generally absorbed through gastrointestinal tract. In present study, the in-vitro binding interactions two of the antiemetic drugs (dimenhydrinate and ondansetron) between Trypsin (Tsn) secreted from pancreas to small intestine for protein digestion were investigated by fluorescence emission spectroscopy (FES), UV-VIS spectroscopy, synchronous fluorescence spectroscopy (SFS), FT-IR spectroscopy and molecular modeling methods. Also, the effect of these drugs on the catalytic activity of Tsn was determined. The fluorescence quenching experiments indicated that each drugs quenched the intrinsic fluorescence of Tsn with their increased concentrations. The results of SFS and UV-VIS spectra proved the interaction of dimenhydrinate and ondansetron with Tsn. FT-IR spectra showed that the secondary structure of enzyme was altered in the presence of the drugs. All these spectroscopy results were validated and explained by molecular docking studies. Both drugs have inhibition effect on the catalytic activity of Tsn and the IC₅₀ values were determined as 2.6 × 10^-4 M and 6.4 × 10^-4 M for dimenhydrinate and ondansetron, respectively. Docking results revealed that the hydrogen bond interaction of dimenhydrinate with active-site residue Ser195 and ondansetron with active-site residues His57 and Ser195 hydrogen bonds might be cause the inhibition of enzyme activity. The results of this study can provide valuable information in the field of pharmacokinetics and pharmacodynamics.

The use of ondansetron for the treatment of nausea in dogs with vestibular syndrome

Background

Vestibular syndrome is often accompanied by nausea. Drugs currently approved for its treatment have been developed to stop vomiting but not nausea. The efficacy of 5-HT₃ receptor antagonists to reduce nausea has been described for chemotherapy, but not for nausea secondary to vestibular disorders.

Methods

Sixteen dogs with vestibular syndrome-associated nausea were included in the open-label, multicentre study. The intensity of nausea-like behaviour was analysed before ondansetron administration (0.5 mg/kg i.v.) and 2 h afterwards, using a validated 5-point-scale. The occurrence and frequency of salivation, lip licking, restlessness, vocalisation, lethargy, and vomiting were assessed.

Results

All dogs initially showed signs of nausea, whereas only 31% showed vomitus. The intensity of nausea was significantly reduced in all dogs (p ≤ 0.0001) 2 h after ondansetron administration, including the clinical signs of nausea analysed in 11 dogs (salivation [p = 0.0078], lip licking [p = 0.0078], restlessness [p = 0.0039], and lethargy [p = 0.0078]) except for vocalisation (p > 0.9999).

Conclusions

The results provide preliminary evidence of the potential benefit of ondansetron in the treatment of nausea, which was present in all examined dogs. Vomiting was only observed in 5 dogs indicating that nausea can occur separately and should not be perceived only as a preceding stimulation of the vomiting centre.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02931-9.

Network pharmacology reveals pharmacological effect and mechanism of Panax notoginseng (Burk.) F. H. Chen on reproductive and genetic toxicity in male mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cisplatin (CP), one of the most commonly used antitumor drugs in clinic, could induce reproductive and genetic toxicity. Traditional Chinese medicine believed that this side effect might be caused by the deficiency of both qi and blood. Panax notoginseng (Burk.) F. H. Chen (PN) is a traditional precious Chinese medicine for nourishing blood and hemostasis, which had the synergistic antitumor and reducing toxicity effects. However, the protective effect and mechanism of PN on CP-induced reproductive and genetic toxicity were still unknown.

AIM OF THE STUDY

This study was designed to illuminate the possible protective effect and mechanism of PN on CP-induced reproductive and genetic toxicity.

MATERIALS AND METHODS

Network pharmacology was first applied to analyze the potential components and targets of PN against CP-induced reproductive and genetic toxicity. Then, the results of network pharmacology were validated in a mouse model of reproductive and genotoxicity induced by CP. Body weight, testis weight, epididymis weight, sperm count, sperm viability and sperm morphology were used to assess protective effects of PN on CP-induced reproductive toxicity. Tail moment in peripheral blood cells and micronucleus in bone marrow cells were used to assess protective effects of PN on CP-induced genetic toxicity. Finally, possible protective targets obtained from network pharmacology, including 8-hydroxy-2-deoxyguanosine (8-OHdG), malondialdehyde (MDA), total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px), were experimentally validated by ELISA.

RESULTS

One hundred and nineteen components of PN and sixty-eight targets of reproductive/genetic toxicity were acquired and constituted as the component-target network. Network pharmacology analysis showed alleviating oxidative stress might play important role in therapeutic mechanism of PN. In verified experiments, PN significantly improved the decline of body weight, testis weight and epididymis weight, increased sperm count and viability, decreased abnormal sperm morphology rate induced by CP in mice. Moreover, PN also significantly decreased the tail moment in peripheral blood cells and micronucleus formation rate in bone marrow cells in CP-induced mice. Finally, not only the decrease of T-SOD and GSH-Px level but also the increase of 8-OHdG and MDA level in serum were restored under PN treatment.

CONCLUSION

Current study found that PN could improve CP-induced reproductive and genetic toxicity, which were probably attributed to alleviating oxidative stress. This finding provided the new perspective for understanding the therapeutic effect of PN on CP-induced reproductive and genetic toxicity and facilitating the clinical use of PN.

Revisiting canine pseudocyesis

Canine (Canis familiaris) pseudocyesis, pseudopregnancy, false pregnancy or nervous lactation is a frequent syndrome observed in non-pregnant, late diestrous or early anestrous females that is characterized by different degrees of mammary gland enlargement, maternal behavior and lactation. Further education about this frequent canine physiological event is still necessary to ensure optimal diagnosis and treatment strategies. Thus, the aim of this article was to review and update the physiopathology, physical and behavioral signs, diagnosis, treatment and prevention of pseudocyesis in bitches in which it is a clinical problem.

Application of the HPLC Method in Parenteral Nutrition Assessment: Stability Studies of Ondansetron

Ondansetron (OND) is a serotonin type 3 receptor antagonist that exhibits antiemetic activity. From the clinical point of view, vomiting and nausea prevention is an important task. Anticancer treatment and recovery impact the patient’s overall state by affecting appetite, well-being, and physical activity, and consequently, nutrition quality. Depending on the patient’s indication and condition, parenteral nutrition is administered to meet full nutritional requirements. In addition, antiemetic drugs can be added to the parenteral nutrition (PN) admixture to treat chemo- or radio-therapy-induced nausea and vomiting. However, adding any medication to the PN admixture can result in the instability of the composition in the overall admixture. This study aimed to develop the HPLC method of determination of OND in Lipoflex special, one of the most popular, ready-to-use PN admixtures. The proposed HPLC method and the sample preparation procedure were suitable for analyzing OND in PN admixture stored under various conditions, such as exposure to sunlight and temperature. It was found that the decomposition of OND during the seven-day storage did not exceed 5% and did not depend on external factors. Based on the conducted research, it is recommended to add OND to Lipoflex special, and it is possible to store such an admixture for seven days.

Efficacy of Auricular Acupressure in Prevention and Treatment of Chemotherapy-Induced Nausea and Vomiting in Patients with Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

More than 40% of patients with cancer have reported that chemotherapy-induced nausea and vomiting (CINV) remained the most debilitating side effects of treatment even in the era of new antiemetics.

OBJECTIVE

The purpose of this review was to systematically evaluate the clinical effect of auricular acupressure (AA) in prevention and treatment of chemotherapy-induced nausea and vomiting.

METHODS

The following databases were searched: PubMed, Cochrane Library, EMBASE, the Web of Science, Chinese Biological Medicine (CBM), Chinese National Knowledge Infrastructure (CNKI), Wanfang, and VIP (from database inception to April 2020). Eligible randomized controlled trials of auricular acupressure in treating CINV were collected, including crossover randomized design study. The meta-analysis was carried out by RevMan software (5.3).

RESULTS

Totally 19 RCTs with 1449 patients met the inclusion criteria. Compared with control groups, the relief efficiency of overall CINV was enhanced by AA combined with antiemetics (RR = 1.31, CI 1.22 to 1.41, p ≤ 0.001). Although the therapeutic effect on acute nausea and vomiting was not obvious, AA still played an important role in reducing delayed nausea and vomiting (delayed nausea frequency: RR = 0.68, CI -1.01 to -1.35, p ≤ 0.001; delayed vomiting frequency: RR = 0.91, CI -1.22 to -0.61, p ≤ 0.001). The likelihood of adverse reactions related to antiemetics was reduced by AA combined with antiemetics (RR = 0.62, CI 0.53 to 0.74, p ≤ 0.001). Statistically significant association was found between AA and incidence of constipation, diarrhea, and tiredness, while there was no statistically significant association between AA and abdominal distension or headache.

CONCLUSION

Auricular acupressure supplementation benefited delayed chemotherapy-induced nausea and vomiting as well as constipation, diarrhea, and tiredness. AA alone or AA supplementation has little effect on acute nausea and acute vomiting. There is no conclusion on whether AA alone is superior to antiemetics in the management of delayed CINV. Further studies are needed to confirm the efficacy of auricular acupressure alone in delayed CINV and anticipatory CINV. The results of this review provided the basis for further research with more rigorous study designs, adequate sample sizes, and standardized implementation to confirm the efficacy of auricular acupressure.

Prospective observational study of the use of omeprazole and maropitant citrate in veterinary specialist care

The proton pump inhibitor omeprazole is administered to dogs with gastroduodenal ulceration or oesophagitis, whereas the neurokinin-1 receptor antagonist maropitant citrate is licensed as an antiemetic drug. In people, omeprazole is overprescribed in hospitals, increasing the risk of adverse effects and imposing unnecessary costs in healthcare. To investigate the use of omeprazole and maropitant in our veterinary specialist hospital, we conducted a prospective observational study in its Medicine and Surgery wards, recording patient data and obtaining contemporaneous information from clinicians about their reasons for administering either drug. In doing so, we find omeprazole and maropitant are administered to a large proportion of dogs, including to many of those with no presenting signs suggestive of gastrointestinal disease. We find prescribing clinicians consider both drugs safe but often underestimate their financial cost. We find the stated reasons and objective predictors of administration of both drugs vary according to clinical setting but that these modalities yield concordant results. Reviewing the manner of administration and stated indications for use of both drugs, we find omeprazole is often administered outside dosing recommendations, and both drugs are frequently administered for aims that are unlikely to be achieved when considering their known biological effects in dogs. In conclusion, our work reveals probable overprescribing of omeprazole and maropitant citrate in hospitalised dogs, highlighting a need for initiatives to decrease inappropriate prescribing.

Prospective, controlled, blinded, randomized crossover trial evaluating the effect of maropitant versus ondansetron on inhibiting tranexamic acid-evoked emesis

OBJECTIVE

To evaluate the incidence of tranexamic acid (TXA)-induced nausea and vomiting after the prophylactic use of 2 antiemetics, ondansetron and maropitant, compared with saline.

DESIGN

Prospective, blinded, placebo-controlled, randomized, crossover study.

SETTING

University research facility.

ANIMALS

Eight adult, purpose-bred Beagles.

INTERVENTION

Dogs received 3 treatments on 3 occasions with a 3-week washout period. Either maropitant (1 mg/kg), ondansetron (0.2 mg/kg), or saline solution was given intravenously in equal volumes, followed 10 minutes later by 50 mg/kg IV TXA. A blinded observer evaluated the dogs for signs of vomiting and nausea for 30 minutes. The severity of nausea was assessed with a visual analog scale (VAS) and recorded at baseline before TXA, and at the end of 3 observational periods: 0-5, 5-15, and 15-30 minutes after TXA. A generalized linear mixed effect model was used to assess for group and period effects. Statistical significance was set at P < 0.05 .

MEASUREMENTS AND MAIN RESULTS

None of the dogs vomited after maropitant. Emesis occurred in 5 out of 8 dogs (62.5%), a median (range) of 1 time (1-2) after ondansetron and 1 time (1-3) after saline. There was a significant effect on vomiting of maropitant against saline (P < 0.0001) but not for ondansetron against saline (P = 0.53). The highest nausea VASs were recorded during the first 5 minutes after TXA with a significant reduction of VAS variability in the maropitant group (P = 0.003). The effect of maropitant and ondansetron against saline on the severity of nausea was not statistically significant (P = 0.069).

CONCLUSION

The neurokinin 1 receptor antagonist maropitant at the dose used, administered IV 10 minutes before 50 mg/kg TXA, was effective in preventing vomiting compared with ondansetron and placebo. Our results support the prophylactic IV administration of maropitant in dogs that are scheduled to receive TXA.

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.

Pharmacokinetics of maropitant citrate in New Zealand White rabbits (Oryctolagus cuniculus)

OBJECTIVE

To determine the pharmacokinetics and adverse effects of maropitant citrate after IV and SC administration to New Zealand White rabbits (Oryctolagus cuniculus).

ANIMALS

11 sexually intact (3 males and 8 females) adult rabbits.

PROCEDURES

Each rabbit received maropitant citrate (1 mg/kg) IV or SC. Blood samples were collected at 9 (SC) or 10 (IV) time points over 48 hours. After a 2-week washout period, rabbits received maropitant by the alternate administration route. Pharmacokinetic parameters were calculated. Body weight, food and water consumption, injection site, mentation, and urine and fecal output were monitored.

RESULTS

Mean ± SD maximum concentration after SC administration was 14.4 ± 10.9 ng/mL and was detected at 1.25 ± 0.89 hours. Terminal half-life after IV and SC administration was 10.4 ± 1.6 hours and 13.1 ± 2.44 hours, respectively. Bioavailability after SC administration was 58.9 ± 13.3%. Plasma concentration at 24 hours was 2.87 ± 1.69 ng/mL after IV administration and 3.4 ± 1.2 ng/mL after SC administration. Four rabbits developed local dermal reactions at the injection site after SC injection. Increased fecal production was detected on the day of treatment and 1 day after treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Plasma concentrations of rabbits 24 hours after SC and IV administration of maropitant citrate (1 mg/kg) were similar to those of dogs at 24 hours. Reactions at the SC injection site were the most common adverse effect detected. Increased fecal output may suggest an effect on gastrointestinal motility. Additional pharmacodynamic and multidose studies are needed.

Pharmacokinetics of single doses of maropitant citrate in adult horses

The neurokinin-1 (NK) receptor antagonist, maropitant citrate, mitigates nausea and vomiting in dogs and cats. Nausea is poorly understood and likely under-recognized in horses. Use of NK-1 receptor antagonists in horses has not been reported. The purpose of this study was to determine the pharmacokinetic profile of maropitant in seven adult horses after single intravenous (IV; 1 mg/kg) and intragastric (IG; 2 mg/kg) doses. A randomized, crossover design was performed. Serial blood samples were collected after dosing; maropitant concentrations were measured using LC-MS/MS. Pharmacokinetic parameters were determined using noncompartmental analysis. The mean plasma maropitant concentration 3 min after IV administration was 800 ± 140 ng/ml, elimination half-life was 10.37 ± 2.07 h, and volume of distribution was 6.54 ± 1.84 L/kg. The maximum concentration following IG administration was 80 ± 40 ng/ml, and elimination half-life was 9.64 ± 1.27 hr. Oral bioavailability was variable at 13.3 ± 5.3%. Maropitant concentrations achieved after IG administration were comparable to those in small animals. Concentrations after IV administration were lower than in dogs and cats. Elimination half-life was longer than in dogs and shorter than in cats. This study is the basis for further investigations into using maropitant in horses.

Pilot prescription survey of antineoplastic agents: real-world data from veterinary teaching hospitals in Japan

The collection of real clinical records from veterinary practices and analysis of these records helps to establish evidence‐based veterinary medicine and further improves animal health and welfare. Prior to the collection of nationwide clinical records, we downloaded the data from the digital accounting systems of two veterinary teaching hospitals in Japan, and the prescriptions of antineoplastic agents were surveyed for a 5‐year period from 2009 to 2013. The ratio of the number of patients prescribed antineoplastic agents to the total number of prescriptions was <5% at both hospitals, and >80% of those patients were dogs. The overall number of prescriptions included more oral rather than injectable formations, whereas among antineoplastic agents, injectable formulations were prescribed more frequently at both hospitals. The most frequently prescribed agents were almost identical at both hospitals: platinum compounds, such as carboplatin and cisplatin (CDDP), vincristine and doxorubicin. The most frequently prescribed product combined with CDDP was doxorubicin at Hospital A. Antiemetic agents combined with CDDP included dexamethasone, ondansetron and metoclopramide, but these antiemetic agents were combined fewer than 10 times among 197 CDDP prescriptions. The prescription history, including the number of prescriptions, dosing intervals and combined medications, was provided by the survey. Although the present database consisted of data from two hospitals, our results indicate that a broad analysis can be conducted using integrated data from multiple hospitals and practices for further cohort studies.

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.

A History of Drug Discovery for Treatment of Nausea and Vomiting and the Implications for Future Research

The origins of the major classes of current anti-emetics are examined. Serendipity is a recurrent theme in discovery of their anti-emetic properties and repurposing from one indication to another is a continuing trend. Notably, the discoveries have occurred against a background of company mergers and changing anti-emetic requirements. Major drug classes include: (i) Muscarinic receptor antagonists-originated from historical accounts of plant extracts containing atropine and hyoscine with development stimulated by the need to prevent sea-sickness among soldiers during beach landings; (ii) Histamine receptor antagonists-searching for replacements for the anti-malaria drug quinine, in short supply because of wartime shipping blockade, facilitated the discovery of histamine (H1) antagonists (e.g., dimenhydrinate), followed by serendipitous discovery of anti-emetic activity against motion sickness in a patient undergoing treatment for urticaria; (iii) Phenothiazines and dopamine receptor antagonists-investigations of their pharmacology as "sedatives" (e.g., chlorpromazine) implicated dopamine receptors in emesis, leading to development of selective dopamine (D2) receptor antagonists (e.g., domperidone with poor ability to penetrate the blood-brain barrier) as anti-emetics in chemotherapy and surgery; (iv) Metoclopramide and selective 5-hydroxytryptamine3(5-HT3) receptor antagonists-metoclopramide was initially assumed to act only via D2 receptor antagonism but subsequently its gastric motility stimulant effect (proposed to contribute to the anti-emetic action) was shown to be due to 5-hydroxytryptamine4 receptor agonism. Pre-clinical studies showed that anti-emetic efficacy against the newly-introduced, highly emetic, chemotherapeutic agent cisplatin was due to antagonism at 5-HT3 receptors. The latter led to identification of selective 5-HT3 receptor antagonists (e.g., granisetron), a major breakthrough in treatment of chemotherapy-induced emesis; (v) Neurokinin1receptor antagonists-antagonists of the actions of substance P were developed as analgesics but pre-clinical studies identified broad-spectrum anti-emetic effects; clinical studies showed particular efficacy in the delayed phase of chemotherapy-induced emesis. Finally, the repurposing of different drugs for treatment of nausea and vomiting is examined, particularly during palliative care, and also the challenges in identifying novel anti-emetic drugs, particularly for treatment of nausea as compared to vomiting. We consider the lessons from the past for the future and ask why there has not been a major breakthrough in the last 20 years.