Effects of using Flunixin Meglumine, Metamizole, and Phenylbutazone on equine kidney functions, urinary mucus, and secretory Immunoglobulin A (IgA) concentrations
Nonsteroidal anti-inflammatory drugs (NSAIDs) are routinely used in equine practices to manage inflammation, endotoxemia, pain or fever in horses. This study was carried out to investigate the effects of the most commonly used nonsteroidal anti-inflammatory drugs on urinary parameters, mucus and immunoglobulin A (IgA) concentrations in horses. Thirty healthy horses (control group) and 20 horses with indications of using either flunixin meglumine (FM), metamizole or phenylbutazone (PHZ) have
... zone (PHZ) have been used and assigned to group 1, 2 or 3, respectively. Serum creatinine, blood urea nitrogen and electrolytes, in addition to urinary creatinine (U-Cr), urine urea nitrogen and urinary electrolytes, were measured using an automatic analyser. Fractional excretions (FE) of sodium, chloride, potassium, calcium, magnesium and inorganic phosphate, in addition to urinary protein (U-Pro):U-Cr and urinary gamma glutamyl transferase (U-GGT):U-Cr ratios were calculated. Urinary mucus and IgA concentrations and their ratios to the urinary creatinine were measured. The FEMg was significantly higher in group 3 (P < 0.033) than the control group. The U-GGT:U-Cr ratio was also significantly increased in group 3 (P < 0.001) compared with the control group. The U-Pro:U-Cr ratio was significantly higher in groups 1 and 2 (P < 0.007 and P < 0.001, respectively) than in the control group. Phenylbutazone (PHZ) had a significantly increased mucus:U-Cr ratio (P < 0.005). Significant increases were observed regarding the IgA:U-Cr ratio in groups 1 (P < 0.007) and 2 (P < 0.014). In conclusion, long-term use of PHZ has an influence on the renal ascending limb of the loop of Henle, and all these drugs could have effects on the proximal tubules. Phenylbutazone causes an increase in urinary mucus secretion, probably as a protective mechanism against the necrotic effect of PHZ. Parameters such as U-Pro:U-Cr and U-GGT:U-Cr ratios and FEMg are helpful in detecting these renal abnormalities.