Because patients have variable responses to drugs due to individual differences in genetic makeup and environmental factors such as intestinal flora and diet, being able to predict a person's response to a medication would be useful and sometimes lifesaving. Now, scientists from England, Sweden, France, and the United States report that studies in animals suggest that a urine test might help physicians to fine-tune drug prescribing by showing how well an individual's body metabolizes the compound (Clayton TA et al. Nature. 2006;440:1073-1077).
Stephenson J. Predicting Drug Response. JAMA. 2006;295(19):2240. doi:10.1001/jama.295.19.2240-c