General and Systematic Veterinary Pharmacology

BIOTRANSFORMATION OF DRUGS / XENOBIOTICS

The chemical alteration of drugs in the body

• To render nonpolar lipid soluble compounds into polar water soluble compounds to enhance their excretion from the body
• Intended to protect body from the foreign substances by making them less toxic and easily excreted
• Primary site - liver
• Other important sites are kidney, intestine, lungs and plasma
• General Pattern of biotransformation - biphasic