Robenacoxib versus meloxicam for the control of peri-operative pain and inflammation associated with orthopaedic surgery in cats: a randomised clinical trial

Evaluation of the analgesic efficacy of grapiprant compared with robenacoxib in cats undergoing elective ovariohysterectomy in a prospective, randomized, masked, non-inferiority clinical trial

OBJECTIVES

The main objective of this study was to compare the postoperative analgesic effects of grapiprant with those of robenacoxib in cats undergoing ovariohysterectomy (OVH).

METHODS

In total, 37 female cats (age range 4 months-10 years, weighing ⩾2.5 kg) were enrolled in a prospective, randomized, masked, non-inferiority (NI) clinical trial. Cats received oral robenacoxib (1 mg/kg) or grapiprant (2 mg/kg) 2 h before OVH. Analgesia was assessed via the Feline Grimace Scale (FGS), the Glasgow Composite Measure Pain Scale-Feline (CMPS-F), von Frey monofilaments (vFFs) and pressure algometry (ALG) 2 h before treatment administration, at extubation, and 2, 4, 6, 8, 18 and 24 hours after extubation. Hydromorphone (<8 h postoperatively) or buprenorphine (>18 h postoperatively) were administered to cats with scores of ⩾5/20 on CMPS-F and/or ⩾4/10 on FGS. NI margins for CMPS-F and vFFs were set at 3 and -0.2, respectively. A mixed-effect ANOVA was used for FGS scores (P <0.05). Data are reported as mean ± SEM.

RESULTS

The data from 33 cats were analyzed. The upper limit of the 95% confidence interval (CI) (0.35) was less than the NI margin of 3 for CMPS-F, and the lower limit of the 95% CI (0.055) was greater than the NI margin of -0.2 for vFFs, indicating NI of grapiprant. The FGS scores were greater than baseline at extubation for both treatments (1.65 ± 0.63; P = 0.001); however, there was no difference between treatments. There was no difference between treatments, nor treatment by time interaction, for vFFs (P <0.001). The CMPS-F scores for both treatments were higher at extubation but returned to baseline after 4 h (P <0.001). For ALG, there was no difference in treatment or treatment by time interaction. The robenacoxib group had lower pressure readings at extubation and 6 h compared with baseline.

CONCLUSIONS AND RELEVANCE

These results indicate that grapiprant was non-inferior to robenacoxib for mitigating postsurgical pain in cats after OVH performed via ventral celiotomy. The impact of grapiprant for analgesia in OVH via the flank is unknown.

Robenacoxib versus meloxicam following ovariohysterectomy in cats: A randomised, prospective clinical trial involving owner-based assessment of pain

BACKGROUND

Injectable non-steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed to queens undergoing ovariohysterectomy (OVH), but the requirement for postoperative administration is unclear and practices vary. Existing studies assessing efficacy rely on pain scoring by experienced clinicians. However, following OVH, most cats are discharged within hours of recovery.

METHODS

Cats undergoing OVH were randomly assigned to two treatment groups: MEL and ROB. Cats in the MEL group (n = 76) received meloxicam (0.2 mg/kg) and those in the ROB group (n = 65) received robenacoxib (2 mg/kg). Owners were contacted by a blinded assessor 3 days postoperatively and asked to identify physical or behavioural changes and to assign pain scores using a numerical rating scale.

RESULTS

More cats in the ROB group displayed abnormal behaviours than cats in the MEL group (p = 0.03). Most owners assigned a pain score of 0 (72%) (n = 101), but pain scores were significantly higher in the ROB group than in the MEL group (p = 0.005).

LIMITATION

Methods of owner assessment of pain in cats have not been validated.

CONCLUSIONS

Both meloxicam and robenacoxib are effective in controlling postoperative pain. Meloxicam may have improved efficacy in certain patient populations. Applying a blanket approach to prescribing NSAIDs to cats undergoing OVH postoperatively may not be necessary. This has safety, environmental and cost implications.

Pharmacology, safety, efficacy and clinical uses of the COX-2 inhibitor robenacoxib

Robenacoxib is a veterinary‐approved non‐steroidal anti‐inflammatory drug (NSAID) of the coxib group. It possesses anti‐hyperalgesic, anti‐inflammatory and anti‐pyretic properties. Robenacoxib inhibits the cyclooxygenase (COX)‐2 isoform of COX selectively (in vitro IC₅₀ ratios COX‐1:COX‐2, 129:1 in dogs, 32:1 in cats). At registered dosages (2 mg/kg subcutaneously in dogs and cats, 1–4 mg/kg orally in dogs and 1–2.4 mg/kg orally in cats), robenacoxib produces significant inhibition of COX‐2 whilst sparing COX‐1. The pharmacokinetic (PK) profile of robenacoxib is characterized by a high degree of binding to plasma proteins (>98%) and moderate volume of distribution (at steady state, 240 ml/kg in dogs and 190 ml/kg in cats). In consequence, the terminal half‐life in blood (<2 h) is short, despite moderate body clearance (0.81 L/kg/h) in dogs and low clearance (0.44 L/kg/h) in cats. Excretion is principally in the bile (65% in dogs and 72% in cats). Robenacoxib concentrates in inflamed tissues, and clinical efficacy is achieved with once‐daily dosing, despite the short blood terminal half‐life. In dogs, no relevant breed differences in robenacoxib PK have been detected. Robenacoxib has a wide safety margin; in healthy laboratory animals daily oral doses 20‐fold (dog, 1 month), eight‐fold (cat, 6 weeks) and five‐fold (dog, 6 months) higher than recommended clinical doses were well tolerated. Clinical efficacy and safety have been demonstrated in orthopaedic and soft tissue surgery, and in musculoskeletal disorders in dogs and cats.

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.

Complications associated with total hip arthroplasty in four large nondomestic felids

CASE DESCRIPTION

A 9-year-old 37-kg sexually intact male snow leopard (Panthera uncia) with no history of lameness but radiographic evidence of right femoral subluxation and flattening of both femoral heads, 2 juvenile (< 1 year old) 25-kg sexually intact male cheetahs (Acinoynx jubatus) with unilateral hind limb lameness resulting from trauma, and an 11-year-old 110-kg sexually intact female Amur tiger (Panthera tigris altaica) with a 2-year history of left hip joint osteoarthritis were examined.

CLINICAL FINDINGS

No clinically relevant clinical findings other than hip joint problems were identified. All 4 felids underwent staged bilateral (snow leopard) or unilateral (cheetahs and tiger [Panthera tigris]) total hip arthroplasty (THA).

TREATMENT AND OUTCOME

In the snow leopard, both femoral THA components were found to be luxated 1 year after surgery. Treatment consisted of autogenous corticocancellous rib graft augmentation of the dorsal acetabular rims and synthetic suture capsulorrhaphies. The snow leopard lived for an additional 4 years with no additional THA-related complications. In the other 3 animals, catastrophic complications (luxation in the cheetahs and femoral fracture in the tiger) occurred shortly after THA. The THA implants were removed, and excision arthroplasty was performed. Long-term outcomes were good in all 3.

CLINICAL RELEVANCE

Findings underscore the challenges associated with THA in large nondomestic felids. Given the high risk for early catastrophic failure as a result of luxation or fracture, plans must be made and resources must be available in case revision surgery or implant removal with excision arthroplasty becomes necessary.

Management of Severe Oral Inflammatory Conditions in Dogs and Cats

Severe oral inflammatory disease is not uncommon in the mouths of canine and feline patients. An approach to oral diagnosis is offered. This article discusses a brief review of important points in the oral diagnosis and management of main canine (canine chronic ulcerative stomatitis (CCUS), eosinophilic stomatitis, and Wegener's granulomatosis (WG)) and feline diseases (feline gingivostomatitis/caudal stomatitis, oral eosinophilic lesions, pyogenic granuloma, and autoimmune diseases with oral manifestations), and-whereby possible-information about the current understanding of disease pathogenesis and treatment is offered.

Retrospective study of aldosterone and progesterone secreting adrenal tumors in 10 cats

Background

Primary hyperaldosteronism caused by adrenal neoplasia has been well described in cats. Multiple corticosteroid abnormalities occur in a subset of affected cats, but characterizations of this syndrome are limited to several case reports.

Objectives

To describe a series of cats with adrenal tumors secreting aldosterone and additional corticosteroids.

Animals

Ten cats with multiple corticosteroid secreting adrenocortical tumors.

Methods

Retrospective case series. Medical records of cats with adrenal tumors secreting both aldosterone and progesterone were identified. Data concerning historical findings, clinicopathologic features, treatments, and outcomes were retrieved from medical records.

Results

All 10 cats had diabetes mellitus in addition to biochemical features of hyperaldosteronism such as hypokalemia. High corticosterone concentrations were observed in all 3 cats in which this corticosteroid was measured. Ultrasound examinations revealed unilateral adrenal tumors in all 10 cases, and the contralateral adrenal gland was either atrophied or not identified in 5 cats. Three of 4 cats developed hypoadrenocorticism after surgical adrenalectomy. Three cats achieved diabetic remission after adrenalectomy. Two cats treated with adrenalectomy survived >1 year, 1 cat survived 6.5 months, and 1 cat was alive 5.5 months after diagnosis. Survival >1 year occurred in 2 of 4 cats treated with medical management alone. Two cats were not treated.

Conclusions and Clinical Importance

The presence of multiple corticosteroid abnormalities should be considered in cats with aldosterone secreting adrenal tumors, especially those with concurrent diabetes mellitus. Both surgical and medical management can result in long‐term survival, although diabetic remission was documented only in cats undergoing adrenalectomy.

Safety evaluation of the interchangeable use of robenacoxib in commercially-available tablets and solution for injection in cats

Background

Robenacoxib (Onsior™) is a non-steroidal anti-inflammatory drug developed for canine and feline use for the control of pain and inflammation. It is available as both tablets and solution for injection.

The objective of this study was to evaluate the safety of the interchangeable use of commercially available robenacoxib formulations when administered to cats orally using 6 mg tablets and subcutaneously using a solution for injection containing 20 mg/mL. Thirty-four naïve healthy 4-month old cats were enrolled in this 37-day study and were randomized to four groups (three robenacoxib and one control). One robenacoxib group received the maximum recommended dose (MRD) rate of each formulation, while the other two received two and three times this dose rate. The cats underwent three 10-day treatment cycles comprised of seven days of once daily oral administration followed by three days of subcutaneous administration. The third cycle was followed by an additional seven days of oral treatment. The control group received oral empty gelatin capsules or subcutaneous saline injections. Assessment of safety was based on general health observations, clinical observations, physical, ophthalmic, electrocardiographic and neurological examinations, clinical pathology evaluations, food consumption, body weight, and macroscopic and microscopic examinations. Blood samples were collected for toxicokinetic evaluation.

Results

Blood concentrations of robenacoxib confirmed systemic exposure of all treated cats. All cats were in good health through study termination and there were no serious adverse events during the study. There were no changes in body weight, food consumption, ophthalmic, physical or neurological examinations during the study. Treatment-related abnormalities were of low occurrence at all doses and included injection site changes (transient edema with minimal or mild, subacute/chronic inflammation histologically) and prolongation of the QT interval. These findings were consistent with previously observed findings in studies with robenacoxib administered separately orally or subcutaneously in cats. Thus, there were no adverse effects that could be attributed specifically to the interchangeable use of oral and injectable robenacoxib.

Conclusions

This 37-day laboratory study supports the safety of interchanging robenacoxib injection at a daily dose of 2 mg/kg with robenacoxib tablets at a daily dose of 1 mg/kg, or vice versa.

Antiinflammatory Drugs

This article reviews the mechanisms of action, clinical use, and recent scientific evidence for the use of nonsteroidal antiinflammatory drugs, grapiprant, acetaminophen (paracetamol), metamizole (dipyrone), and corticosteroids in pain management. The discussion is presented with an emphasis on the treatment of acute pain.

Robenacoxib in the treatment of pain in cats and dogs: safety, efficacy, and place in therapy

Robenacoxib is a novel nonsteroidal anti-inflammatory drug (NSAID) of coxib class developed for the control of inflammation and pain in dogs and cats. It shows high selectivity for the cyclooxygenase-2 (COX-2) enzyme in rats, cats, and dogs. Robenacoxib is available in both injectable and tablet formulations. This review initially focuses on the preclinical pharmacology of robenacoxib in rats that includes its high affinity for COX-2 enzyme and weaker and rapidly reversible binding for COX-1 enzyme in in vitro and ex vivo models of inflammation and its pharmacokinetics in the blood and inflammatory exudate, selective tissue distribution, and safety. These basic pharmacological profiles highlight the suitability of robenacoxib for use in target species, such as cats and dogs. Since the level of expression and activity of COX enzymes is species specific, COX-2-selective inhibition and the resultant effects of coxibs must be studied in target species. The pharmacological and toxicological profiles of robenacoxib in cats and dogs have been discussed prior to reviewing its clinical efficacy and safety. Large, multicenter field trials conducted in cats and dogs demonstrated the noninferior efficacy and safety of robenacoxib compared with noncoxib NSAIDs used in dogs and cats. These trials investigated the efficacy of robenacoxib against various acute and chronic painful conditions. Robenacoxib produced superior efficacy to placebo and COX-2 preferential inhibitors in postsurgical cats. The tissue-selective anti-inflammatory activity of robenacoxib has been demonstrated in dogs with osteoarthritis. Robenacoxib has also been shown to be safe in healthy dogs and cats receiving antihypertensive drugs and loop diuretics that could cause renal injury. The developmental objective of coxibs, comparable efficacy but superior safety to less selective/nonselective NSAIDs, is well established with robenacoxib in preclinical studies. More studies need to be conducted to fully explore the benefits of robenacoxib in clinical subjects.

Comparison of post-operative analgesic efficacy of tolfenamic acid and robenacoxib in ovariohysterectomized cats

The objective of this study was to evaluate the efficacy of a non-selective COX inhibitor (tolfenamic acid) and a selective COX-2 inhibitor (robenacoxib) for post-operative pain control in cats. Thirty cats undergoing ovariohysterectomy were randomly divided into three groups: the control (placebo) group, the tolfenamic acid (4 mg/kg/day) group, and the robenacoxib (1 mg/kg/day) group. Non-steroidal anti-inflammatory drugs (NSAIDs) were administered orally 2 hr before anesthesia induction and 24 and 48 hr post-operation. Buccal mucosal bleeding times (BMBTs) were assessed prior to anesthesia induction. Colorado pain scores and composite pain scores were evaluated in a blinded fashion before induction and 2, 8, 24, 30 and 48 hr post-operation. The Colorado pain scores of cats receiving robenacoxib were significantly lower than those of cats in the control group at 30 (P=0.0126) and 48 (P=0.0439) hr post-operation. The composite pain scores of cats from the robenacoxib group were lower than those of cats in the control group at 30 (P=0.0299) and 48 (P=0.0103) hr post-operation. The Colorado pain scores of cats receiving tolfenamic acid were significantly lower than those of cats in the control group at 30 hr (P=0.0186) post-operation. The composite pain scores in cats in the tolfenamic acid group were lower than the scores of cats in the control group at 24 (P=0.0403) and 48 (P=0.0413) hr post-operation. BMBTs remained within normal limits in all groups. Both tolfenamic acid and robenacoxib are useful for post-operative pain control in cats.

Evaluation of injectable robenacoxib for the treatment of post-operative pain in cats: results of a randomized, masked, placebo-controlled clinical trial

Background

Few pharmaceuticals are registered in cats for the management of post-operative pain and inflammation. The objective of this study was to assess the field efficacy and safety of an injectable formulation of the nonsteroidal anti-inflammatory drug robenacoxib in cats undergoing surgery. The study was a multi-center, prospective, randomized, masked, parallel-group, placebo-controlled clinical trial. A total of 349 cats were enrolled and underwent surgery comprising forelimb onychectomy, as an example of orthopedic surgery, plus either ovariohysterectomy or castration. All cats received butorphanol prior to anesthesia and forelimb four-point regional nerve blocks with bupivacaine after induction of general anesthesia. Cats were randomized to receive daily subcutaneous (s.c.) injection of robenacoxib, at a target dosage of 2.0 mg/kg (n = 174), or placebo (n = 175) once prior to surgery and for an additional two days post-operatively.

Results

Significantly (P = 0.037) fewer cats administered robenacoxib received additional analgesia rescue therapy (34 of 173, 19.7 %) compared to cats given placebo (73 of 175, 41.7 %). The percentage of treatment success was therefore 80.3 % with robenacoxib and 58.3 % with placebo. Behavior, posture, pain on palpation of the paw and soft tissue surgery sites, and overall pain were significantly (P < 0.05) improved versus placebo at various time points within the first 8 h in cats receiving robenacoxib. The most frequently reported adverse events were incision site infection/dehiscence, bleeding, vomiting, decreased appetite and lethargy. Frequencies of reported adverse clinical signs, hematology, serum chemistry and urinalysis variables, and body weight changes were similar between groups. There were no significant changes from baseline with robenacoxib in hepatic, hematological or renal clinical pathology variables.

Conclusions

Robenacoxib by s.c. injection was effective and well tolerated in the control of post-operative pain associated with orthopedic, ovariohysterectomy and castration surgery in cats.

Effect of benazepril, robenacoxib and their combination on glomerular filtration rate in cats

Background

Combined use of angiotensin-converting enzyme inhibitors and nonsteroidal anti-inflammatory drugs may induce acute kidney injury in humans, especially when combined with diuretics. The objective of this investigation was to evaluate the effects of benazepril, robenacoxib and their combination in healthy cats.

In each of two studies (study 1 followed by study 2), 32 healthy cats were randomised to one of four groups (n = 4 male and 4 female cats per group) in a parallel-group design. The groups received orally once daily for 7 days either placebo (control group), benazepril, robenacoxib or benazepril plus robenacoxib. In study 2, all groups received in addition 0.5 mg/kg furosemide twice daily by subcutaneous injection for 7 days.

Results

Benazepril, robenacoxib and their combination were well tolerated as evidenced from lack of clinical signs and no negative effects on body weight, feed consumption and clinical chemistry, haematology and urinalysis variables.

The primary endpoint of the study was the glomerular filtration rate (GFR), which was estimated from the plasma clearance of iohexol. In the absence of furosemide, GFR was significantly higher in cats receiving the combination of benazepril plus robenacoxib compared to the other three groups, and was also significantly higher in females receiving only benazepril compared to the control.

Administration of furosemide induced diuresis, reduced GFR and activated the renin-aldosterone-angiotensin system, evidenced from increased plasma renin activity and plasma aldosterone concentrations. Compared to the control group in cats treated with furosemide, GFR was increased by benazepril (females only) but decreased by robenacoxib (males only). Benazepril, robenacoxib and their combination significantly inhibited the increase in plasma aldosterone induced by furosemide.

Conclusions

The combination of benazepril and robenacoxib was well tolerated and either increased or had a neutral effect on GFR in healthy cats without or with concomitant furosemide. The combination of benazepril and robenacoxib reduced plasma aldosterone concentrations increased by furosemide. It is recommended to test the efficacy and safety of the combined use of benazepril and robenacoxib in cats with clinical disease, notably proteinuric chronic kidney disease.