Effect of glomerular filtration rate on clearance and myelotoxicity of carboplatin in cats with tumors

Objective—To characterize the pharmacokinetic disposition of carboplatin and determine whether glomerular filtration rate (GFR) could be used to predict carboplatin clearance and myelotoxic effects in cats with tumors. Animals—10 cats with tumors. Procedure—Glomerular filtration rate was assessed in each cat by monitoring plasma clearance of technetium Tc 99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA). Each cat received carboplatin (200 mg/m2 of body surface area) administered as an IV bolus. Plasma platinum concentrations were measured via atomic absorption spectrophotometry, and pharmacokinetic analysis was performed. A CBC was performed weekly for each cat, and the correlation between the area under the concentration-versus-time curve (AUC) and the severity of myelosuppression was calculated. Least squares regression analysis was performed to determine whether GFR could be used to predict plasma platinum clearance (ClPt). Results—For all cats, AUC measurements ranged from 0.99 to 4.30 min·...