Non-steroidal anti-inflammatory drugs are a mainstay of analgesia, especially in cases of long-term pain such as osteoarthritis or other musculoskeletal diseases. NSAIDs are able to address the source of inflammation and as such reduce downstream effects in ways that pure analgesics cannot. However, they are not without adverse effects, and concerns have long been present for the use of NSAIDs in cats due to the risk of kidney damage. This has been compounded in cats suffering from chronic renal disease, where the use of NSAIDs has long been avoided. However, there is significant overlap between cats with renal disease and with arthritis, and so the ability to use NSAIDs in cats with CKD would be advantageous. Previous data has suggested meloxicam may be relatively safe in cats with early to mid-stage CKD. Robenacoxib is a more COX-2 selective NSAID that may have a safer dosing range and smaller adverse effect profile than less selective drugs.
The purpose of this study was to evaluate the safety and adverse effects of robenacoxib in cats with chronic musculoskeletal disease. The authors reviewed and combined data from four previous studies evaluating the safety of robenacoxib.
Inclusion and exclusion criteria varied between the studies, which were based in several different countries. In general, they required demonstration of chronic musculoskeletal pain for inclusion criteria. Exclusion criteria were general concomitant medical disorders, analgesics, or medications predisposing to gastric ulceration or renal damage.
After enrollment, cats were randomized to receive robenacoxib or placebo once daily for 12 weeks in study 1, 4 weeks in study 2, and 6 weeks in studies 3 and 4. Studies 3 and 4 also included a crossover component. Cats from the crossover component were excluded from adverse effect analysis due to impossibility of attribution, however, their inclusion would not change statistical outcomes.
Both clinical and hematologic adverse effects were investigated. Efficacy was not considered in this study. The primary outcome was the number of cats in each group with at least one adverse event. Various secondary clinical and hematologic adverse events were also investigated.
The proportion of cats with at least 1 reported adverse effect was 47.7% with robenacoxib compared to 41.0% with placebo and was not significantly different (P = .15). The relative risk of an AE was calculated as 1.15 (P = .20), and the number needed to harm was 14.8. There was no significant difference between the robenacoxib and placebo groups in the number of clinical signs reported. The most common AEs were emesis, anorexia, diarrhea, and lethargy.
No significant hematologic, urinary or biochemical differences were seen between groups.
Some limitations were present in this study. It did not include a large number of cats, and the follow-up time was relatively short compared to the expected duration of therapy. Cats with severe concurrent disease were also excluded. While the study did review several other papers, it did not compare the relative qualities of the manuscripts.
The authors concluded that robenacoxib was not associated with an increased risk of adverse effects in cats with chronic kidney disease compared to placebo. Further work is needed in cats with concurrent diseases or treated for longer time spans.
Lascelles BDX, Court MH, Hardie EM, Robertson SA. Nonsteroidal anti-inflammatory drugs in cats: a review. Vet Anaesth Analg. 2007; 34: 228- 250.
Guillot M, Moreau M, Heit M, Martel-Pelletier J, Pelletier JP, Troncy E. Characterization of osteoarthritis in cats and meloxicam efficacy using objective chronic pain evaluation tools. Vet J. 2013; 196: 360- 367.
King JN, King S, Budsberg SC, et al. Clinical safety of robenacoxib in feline osteoarthritis: results of a randomized, blinded, placebo-controlled clinical trial. J Feline Med Surg. 2015; 18: 632- 642.
Related Blog Posts