The Life of a drug Rx... ABSORPTION DISTRIBUTION METABOLISM EXCRETION Site of Blood to site of Biotransformation Removal of administration Action(target of Drug Drug from body to blood organ) 6
The Life of a Drug Rx6 6 ABSORPTION Site of administration to blood DISTRIBUTION Blood to site of Action (target organ) METABOLISM Biotransformation of Drug EXCRETION Removal of Drug from body
1.Absorption of Drugs Drug at site of administration Absorption is the transfer of Absorption a drug from its site of (input) administration to the Drug in plasma bloodstream via one of 2 Distribution several mechanisms. Drug in tissues 3 Metabolism Metabolite(s)in tissues 4 Elimination (output) Drug and/or metabolite(s) in urine,bile,or feces 7
1.Absorption of Drugs Absorption is the transfer of a drug from its site of administration to the bloodstream via one of several mechanisms. 7
Routes of Drug Administration Orally Parenteral:IV,IM,SC @Sublingually Sublingual Rectally □Inhalation Inhalation Oral Topical:drug-containing skin patch Transdermal patch Parenterally (given in liquid form by Topical injection with a needle and syringe) ·Intravenous(m.) ·Intramuscular(im.) Rectal ·Subcutaneous(sc.) 8
Routes of Drug Administration Orally Sublingually Rectally Inhalation 8 Topical: drug-containing skin patch Parenterally (given in liquid form by injection with a needle and syringe) • Intravenous (iv.) • Intramuscular (im.) • Subcutaneous (sc.)
Oral absorption First-pass metabolism Esophaqus Gall Small inesune Rectum If the drug is rapidly metabolized in the liver or gut wall,the amount of unchanged drug that reaches the systemic circulation is decreased. 9
Oral absorption First - pass metabolism 9 If the drug is rapidly metabolized in the liver or gut wall, the amount of unchanged drug that reaches the systemic circulation is decreased
Sublingual absorption allows a drug to diffuse into the capillary network and,therefore, to enter the systemic circulation directly. @Rapid absorption (Pass straight into systemic circulation) 8 Glenmapk NM0C6B462-146-25 NITROGLYCERIN Convenience of administration TABLETS,USP Rx Only 25 Sublingua Tablets @Avoidance of first-pass metabolism 10
Sublingual Sublingual absorption absorption allows a drug to diffuse into the capillary network and, therefore, to enter the systemic circulation directly. 10 Rapid absorption (Pass straight into systemic circulation) Convenience of administration Avoidance of first-pass metabolism