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• BIOTRANSFORMATION

DR. RAVI KUMAR SINGODIA

Although every tissue has some ability to metabolize drugs, the liver is the principal organ of drug metabolism. Other tissues that display considerable activity include the gastrointestinal tract, the lungs, the skin, and the kidneys. Following oral administration, many drugs (eg, isoproterenol, meperidine, pentazocine, morphine) are absorbed intact from the small intestine and transported first via the portal system to the liver, where they undergo extensive metabolism.

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Humans are exposed daily to a wide variety of foreign compounds called xenobiotics—substances

absorbed across the lungs or skin or, more commonly, ingested either unintentionally as compounds

present in food and drink or deliberately as drugs for therapeutic or "recreational" purposes.

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