Pharmacokinetic variability, hepatic metabolism of drugs, clearance with renal elimination, drug interactions (8) http://www.cnn.com/2007/HEALTH/conditions/09/26/unapproved.drugs/index.html NEW YORK (CNN)-- Every year, doctors write approximately 65 million prescriptions for drugs not yet approved by the U.S. Food and Drug Administration, the federal agency that
regulates prescription drugs.