Effect of seven-day administration of carprofen or meloxicam on renal function in clinically healthy miniature pigs

Carprofen or meloxicam are nonsteroidal anti-inflammatory drugs (NSAIDs), which may elicit a variety of renal disturbances. Prior to this study, the effects of carprofen or meloxicam on renal function in pigs were unknown. A total of 21 clinically healthy Goettingen miniature pigs (36.9 ± 7.22 kg) were divided into three groups based on what they were administered – carprofen, meloxicam or saline. First, blood was collected from the jugular vein and urine by ultrasound-guided cystocentesis. Serum urea (U) and creatinine (CR), fractional clearance of sodium (FCNa), urine gamma-glutamyltransferase (GGT) and alkaline phosphatase (ALP) activities, urine protein/creatinine ratio (UP/UC), urine gamma-glutamyltransferase/creatinine ratio (GGT/CR) and urine alkaline phosphatase/creatinine ratio (ALP/CR) and urine analysis – urine specific gravity (USG) and sediment microscopy were assessed before and seven days after daily intramuscular administration (IM) of saline (1.5 ml per animal), carprofen (2 mg/kg) or meloxicam (0.1 mg/kg). All animals had identical housing, feeding and unlimited water intake and had not undergone surgery or been administered any medication for three months prior to this. All pigs served as control groups for an experimental study of fracture healing using transplantation of mesenchymal stem cells and scaffolds. The data were analyzed using a one way ANOVA and a Mann-Whitney test (P < 0.05). In pigs receiving carprofen, serum urea and creatinine were significantly decreased, compared to the control (P < 0.01) or meloxicam (P < 0.05) groups. In animals receiving meloxicam FCNa was significantly increased (P < 0.05) and urine specific gravity significantly decrease (P < 0.05) compared to the pretreatment values. Two carprofentreated pigs had a slight increase in renal tubular epithelial cells upon urine sediment examination. Intramuscular administration of carprofen or meloxicam in healthy miniature pigs for seven days causes no clinically important changes in selected renal parameters (without azotemia). However these changes indicate mild damage of renal tubules. Despite these findings, meloxicam or carprofen are recommended for analgesia in healthy pigs.