Safety of reduced-dosage ketoprofen for long-term oral administration in healthy dogs

Safety and efficacy of reduced dosage ketoprofen with or without tramadol for long-term treatment of osteoarthritis in dogs: a randomized clinical trial

BACKGROUND

This study aimed to evaluate the safety and efficacy of reduced-dosage ketoprofen with or without tramadol in dogs. Five healthy dogs receiving standard-dosage ketoprofen (2 mg/kg SC, then 1 mg/kg PO daily) comprised Group A. Twenty dogs with osteoarthritis were randomized to receive reduced-dosage ketoprofen (0.5 mg/kg SC once; 0.25 mg/kg PO daily) alone (Group B) or in combination with tramadol (5 mg/kg/day PO) (Group C). Treatments were administered for 28 days. Platelet aggregation time (PAT), gastrointestinal (GI) endoscopy and glomerular filtration rate (GFR) were performed up to 60 days after treatment initiation. Pain was scored using a validated clinical metrology instrument up to D120. Data were analyzed with general linear mixed model for repeated measures (α = 0.05).

RESULTS

PAT was not different between groups but was increased with time for all groups. GI lesion scores were higher in Group A than Groups B and C (day 28; P = 0.005) and were increased with time for Group A (P = 0.005). GFR was lower in Group A than Groups B and C (day 28; P < 0.01) and were decreased with time for group A (P < 0.001). Standard-dosage ketoprofen administration resulted in clinically relevant adverse effects. Pain score decreased in both treated groups (B and C) from D0 to D28. Need of rescue analgesia from D29 to D120 was higher in Group B than in Group C (P = 0.039).

CONCLUSIONS

The long-term safety profile of reduced-dosage ketoprofen is similar whether the drug is administered alone or in combination with tramadol to dogs with osteoarthritis. Analgesic efficacy of the combination looks attractive.

The renal effects of NSAIDs in dogs

The quality of life for dogs with osteoarthritis can often be improved with nonsteroidal anti-inflammatory drugs (NSAIDs); however, the number of adverse drug events associated with NSAID use reported to the Federal Drug Administration Center for Veterinary Medicine is higher than that for any other companion animal drug. Of those events, adverse renal reactions are the second most reported. NSAIDs produce pharmacologic effects via inhibition of cyclooxygenase (COX), which decreases production of prostanoids. Prostaglandins are synthesized by both the COX-1 and COX-2 enzymes in the healthy kidney and influence renal blood flow, glomerular filtration rate, renin release, and Na excretion. There are important species differences in the renal expression of COX-1 and COX-2. For example, dogs have higher basal levels of COX-2 expression in the kidney compared with humans. In addition, in dogs with chronic kidney disease, an increase in COX-2 expression occurs and synthesis of prostaglandins shifts to the COX-2 pathway. For those reasons, NSAIDs that target COX-2 may be expected to adversely affect renal function in dogs, especially dogs with chronic kidney disease. The purpose of this review was to evaluate the literature to report the renal effects of NSAIDs in dogs.

Systematic review of nonsteroidal anti-inflammatory drug-induced adverse effects in dogs

The aim of this systematic review was to identify, assess, and critically evaluate the quality of evidence of nonsteroidal anti-inflammatory drug (NSAID)-induced adverse effects in dogs. Original prospective studies published in peer-reviewed journals in English (1990-2012) that reported data on the safety of NSAIDs administration in dogs were searched. For each study, design type (I, II, III, or IV) and assessment of quality (+, Ø, -) were rated. For each drug, quantity and consistency rating (***, **, *) and strength of evidence (high, moderate, low, or extremely low) were identified and evaluated. The strength of evidence was defined in terms of how applicable and relevant the conclusions were to the target population. Sixty-four studies met the inclusion criteria. Thirty-five (55%) research studies and 29 (45%) clinical trials were identified. A high strength of evidence existed for carprofen, firocoxib, and meloxicam; moderate for deracoxib, ketoprofen, and robenacoxib; and low for etodolac. Quality and consistency rating were as follows: carprofen (***/***), deracoxib (**/***), etodolac (*/unable to rate), firocoxib (***/**), ketoprofen (**/***), meloxicam (***/***), and robenacoxib (**/**), respectively. Adverse effects were detected in 35 studies (55%) and commonly included vomiting, diarrhea, and anorexia. Three studies (5%) reported a power analysis related to adverse effects of ≥80%. In randomized, placebo-controlled, blinded studies (n = 25, 39%), the incidence of adverse effects was not statistically different between treated and control dogs. Finally, most studies were not appropriately designed to determine the safety of NSAIDs, and involved a healthy nongeriatric population of research dogs.

Postoperative analgesic effects of dexketoprofen, buprenorphine and tramadol in dogs undergoing ovariohysterectomy

The objective of this study was to compare the postoperative analgesic effects of dexketoprofen, tramadol, and buprenorphine in dogs undergoing ovariohysterectomy. Seventy-five adult female dogs were randomly assigned to receive an intravenous injection (IV) of 1mg/kg of dexketoprofen (D), 0.02 mg/kg of buprenorphine (B) or 2mg/kg of tramadol (T). Pain assessment was performed during 48 h after ovariohysterectomy using a dynamic interactive visual analogue scale (DIVAS) and Glasgow composite measure pain scale (CMPS-SF). Rescue analgesia was required in 43%, 21%, and 5% of dogs in the B, T, and D groups, respectively, with significant differences between B and D (p=0.010) groups. The DIVAS and CMPS-SF values of the B group were significantly higher than those of the T and D groups. The most common undesirable effect was dysphoria in dexketoprofen group. Tramadol and dexketoprofen provide superior postoperative analgesia compared with buprenorphine in dogs undergoing ovariohysterectomy.

Target animal safety study of meloxicam administered via transmucosal oral spray (Promist(®) technology) for 6 months in dogs

This study evaluated the safety of meloxicam administered via transmucosal oral spray (TMOS) at 1, 2, 3 and 5 times the maximum proposed dose for 6 months in dogs. After baseline assessments, 40 Beagles (20 M, 20 F) were randomized to gender-balanced groups administered either water or meloxicam TMOS at 1, 2, 3 and 5 times the maximum proposed dose once daily for 26 weeks. Dogs were subjected to daily food consumption measurements and clinical and dose site observations. Periodic evaluations were made of body weight, physical examination, clinical pathology, urinalysis, buccal mucosal bleeding time (BMBT) and gastroduodenal endoscopy. At study completion, all dogs were subjected to gross necropsy. Histopathology was performed on tissues from dogs in groups 0X and 5X and from selected tissues in other dose groups. Clinical signs of previously reported NSAID-associated gastrointestinal upset were noted with higher frequency in meloxicam-dosed animals than in controls. Despite the presence of statistically significant effects on some clinicopathological variables, no toxicologically relevant dose-associated effects were determined on these or on food consumption, dose site observations, body weight, physical examination, urinalysis, BMBT, endoscopic examination or gross and histopathological examination of necropsy tissues.

An overview of glomerular filtration rate testing in dogs and cats

Determination of glomerular filtration rate (GFR) is a valuable, yet underused, diagnostic tool for evaluating renal function in dogs and cats. This article first reviews the hormonal and hemodynamic factors which contribute to GFR, followed by a description of considerations when selecting a pharmacokinetic model and methods of animal-to-animal standardization. The best-characterized existing GFR markers, including creatinine, radiolabeled markers, and iohexol, are reviewed in depth, as well as alternative but lesser used techniques. A weighted means analysis of reported GFR measurements in healthy dogs and cats and a review of selected studies that have examined GFR alterations in animals with naturally occurring and experimental diseases provide the reader with preliminary guidelines on expected GFR results in these species and disease conditions.

Effects of prednisone alone or prednisone with ultralow-dose aspirin on the gastroduodenal mucosa of healthy dogs

BACKGROUND

The coadministration of prednisone and ultralow-dose aspirin has been recommended for the management of various diseases, but the safety of this combination in dogs has not been studied.

HYPOTHESES

The gastroduodenal lesions associated with prednisone and ultralow-dose aspirin administration will be similar to those caused by prednisone alone, but both treatments will result in more severe lesions than placebo.

ANIMALS

Eighteen healthy adult purpose-bred dogs.

METHODS

Randomized, blinded, placebo-controlled study of 3 treatment groups for 27 days: placebo, prednisone, and prednisone and aspirin. Gastroduodenoscopy was performed before and on days 5, 14, and 27 of treatment and mucosal lesions scores were assigned. Mucosal lesion scores were compared by a Kruskal-Wallis test. Clinical signs were compared by the Friedman's chi-square test (significance at P < .05).

RESULTS

There were no significant differences in the gastroduodenal lesion scores among groups, or within groups at any time during the study. Significantly more dog-days of diarrhea occurred in the prednisone and aspirin group during treatment, compared with baseline. No significant differences in clinical signs were found among any of the groups.

CONCLUSION

The concurrent use of prednisone and ultralow-dose aspirin did not increase the severity of gastroduodenal lesions compared with prednisone or placebo. Coadministration of prednisone and ultralow-dose aspirin increases the frequency of mild, self-limiting diarrhea in some dogs.

Pathophysiology of cyclooxygenase inhibition in animal models

Cyclooxygenase (COX) catalyzes the conversion of arachidonic acid into prostaglandins (PGs), which play a significant role in health and disease in the gastrointestinal tract (GI) and in the renal, skeletal, and ocular systems. COX-1 is constitutively expressed and found in most normal tissues, whereas COX-2 can be expressed at low levels in normal tissues and is highly induced by pro-inflammatory mediators. Inhibitors of COX activity include: (1) conventional nonselective, nonsteroidal anti-inflammatory drugs (ns-NSAIDs) and (2) COX-2 selective nonsteroidal anti-inflammatory drugs (COX-2 s-NSAIDs). Inhibition of COX-1 often elicits GI toxicity in animals and humans. Therefore, COX-2 s-NSAIDs were developed to provide a selective COX-2 agent, while minimizing the attendant COX-1-mediated GI toxicities. Rats and dogs overpredict COX inhibition for renal effects such as renal handling of electrolytes in humans. COX inhibitors are shown to have both beneficial and detrimental effects, such as on healing of ligament or tendon tears, on the skeletal system in animal models. Certain ophthalmic conditions such as glaucoma and keratitis are associated with increased COX-2 expression, suggesting a potential role in their pathophysiology.

Evaluation of the adverse effects of oral firocoxib in healthy dogs

This study evaluated the adverse effects of oral firocoxib in dogs. Six dogs (20.2+/-6.3 kg) were studied. Values for complete blood count (CBC), serum urea, creatinine, alanine transaminase, alanine phosphatase, gamma-glutamyl transferase, occult blood in feces, platelet aggregation, and buccal mucosal bleeding time were measured before and 7, 14, 21, and 29 days after SID treatment with firocoxib 5.3+/-0.34 mg/kg (FG) or lactose 1 mg/kg (LG) for 28 days, in a randomized crossover study. Gastrointestinal (GI) tract endoscopy was performed before treatment began and at 29 days. Lesions were scored from grade 0 to 6. Data were analyzed using anova and paired t-tests (P<0.05). None of the dogs presented adverse clinical effects. There were no significant changes in CBC, biochemical profiles within groups, or differences between groups. Pretreatment mean+/-SD bleeding time (LG, 70.7+/-32.1 sec; FG, 75.8+/-38.1 sec) and platelet aggregation (LG, 86.4+/-10.2%; FG, 85.6+/-9.2%) were not significantly different from readings at 29 days (LG, 95.2+/-25 sec; FG, 91.7+/-24 sec and LG, 73.2+/-15.1%; FG, 84+/-10.3%) nor the groups were different. None of the dogs had positive fecal occult blood tests, and endoscopic lesion scores were grade 0 both before treatment and at 29 days. Administration of firocoxib did not cause any adverse effects on GI, or hematological or serum biochemical variables and appears to have been well tolerated by dogs.

The Interaction between Orally Administered Non-Steroidal Anti-Inflammatory Drugs and Prednisolone in Healthy Dogs

The interaction between oral non-steroidal anti-inflammatory drugs (NSAIDs) and prednisolone administered concurrently for 30 days was studied in 18 healthy dogs divided into 3 groups of 6 dogs each: a drug-free negative control group (NC group) given 2 gelatin capsules; a group given meloxicam (0.1 mg/kg) and prednisolone (0.5 mg/kg) (MP group); and a group given a reduced dosage of ketoprofen (0.25 mg/kg, p.o.) and prednisolone (0.5 mg/kg, p.o.) (KP group). The dogs were periodically monitored by physical examinations, blood analyses, endoscopic examinations, fecal occult blood tests, renal function tests [effective renal plasma flow (ERPF) and glomerular filtration rate (GFR)], urinalyses [urinary sediments, and urinary micro-albumin to creatinine ratio (UAlb/Cre)], urinary enzyme indices, and haemostatic function tests [buccal mucosa bleeding time (BMBT), cuticle bleeding time (CBT)]. Significant changes were observed in the KP group, including a decrease of ERPF and GFR, an increased UAlb/Cre ratio, prolonged BMBT and CBT, as well as the presence of more severe grades of endoscopic lesions and fecal occult blood. In both the MP and KP groups, abnormal enzymuria with exfoliation of renal tubular epithelial cells in the urine was found. However, no significant changes in any of the other tests were observed in the MP group compared with the NC group. These findings suggest that the combination of NSAIDs, even selective COX-2 inhibitors, with prednisolone may be contraindicated due to the potential for serious adverse effects on the kidneys, the platelets, and the gastrointestinal tract.