Creatinine is a product of muscle contraction. Because it is produced from within and released into body fluids at a relatively constant rate, the level of creatinine in urine may be used as an indication of body hydration. Since measured drug levels can fluctuate with the level of creatinine, a key aspect of your laboratory testing is creatinine adjustment. With creatinine adjusted drug levels, you can better monitor drug usage and redefine program goals to increase treatment effectiveness.
Creatinine adjusted values are for clinical pharmacokinetic comparison only; these values are not intended for forensic or punitive use.
Reference: Fraser AD, Worth D. Urinary excretion profiles of 11-nor-9-carboxy-Delta9-tetrahydrocannabinol: a Delta9-THC-COOH to creatinine ratio study #2. Forensic Sci Int. 2003 Apr 23;133(1-2):26-31.