New York Metro Local Section January 2011

(B)  Calculation based upon plasma creatinine, age, race, and sex

Since sample collection errors such as incomplete bladder emptying often lead to errors in determining creatinine clearance, the National Kidney Foundation guidelines recommend the use of a calculation estimate of glomerular filtration rate (e GFR) reported along with the serum or plasma creatinine as a means of screening patients for chronic kidney disease. One equation ( the abbreviated modification of diet in renal disease formula)
(eGFR mL/min/1.73m2) = 186 X Plasma Cr -1.154 X Age -.203 X .742 (if female) X 1.21 (if Afro-American)

(C) Testing for single nucleotide polymorphisms known to affect drug metabolism

Pharmacogenomics refers to the study of genes that affect the performance of a drug in an individual. One method is to test for single nucleotide polymorphisms (SNPs) using DNA microarrays in genes such as those that code for the cytochrome P450 enzymes involved in the metabolism of many drugs. Genetic variations of this enzyme may account for individual pharmacokinetic differences and can be used to predict the efficacy of the drug used to manage pain.

Reference: Reference: Robert R. Harr, Clinical Laboratory Science Review third edition