Effect of intravenous calcium administration on gentamicin-induced nephrotoxicosis in ponies

Objective - To determine whether supplemental IV calcium administration would attenuate or prevent gentamicin-induced acute renal failure, defined as an increase in serum creatinine concentration ≤ 50% above baseline. Animals - 10 healthy pony names. Procedure - Pony mares were randomly assigned to receive calcium at a dosage of 20 mg/kg of body weight or saline solution IV, twice daily for 14 days. All pony mares received gentamicin at a dosage of 20 mg/kg IV every 8 hours for 14 days. Gentamicin pharmacokinetic, serum biochemical, and urinalysis data were measured every other day for the 14- day study period. Renal histologic examination was performed, and results were scored at the end of the 14-day period. Results - 4 of 5 mares not receiving calcium supplementation developed acute renal failure. Only 1 of the 5 mares receiving calcium supplementation developed acute renal failure. Over the course of the study, pony mares receiving calcium supplementation had significantly fewer changes in urinalysis variables, and significantly less microscopic renal damage. Conclusion - Daily IV administration of calcium attenuated gentamicin-induced acute renal failure. Clinical Relevance - Calcium supplementation may help diminish the risk of acute renal failure associated with aminoglycoside antibiotics.