药理学What is pharmacology.docVIP

药理学What is pharmacology? ①药动Pharmacokinetics：what the body does to drug. Refer to the way the body handles drug absorption, distribution ,metabolism, excretion and toxicity. Onse it is determined, rational, dosage , regimens can be instituted.②药效Pharmacodynamics：what the drug does to body.(1drug receptor.2effect of drug-efficacy 3responses to drug 4toxixity and adverse effests of drug) ③治疗Pharmacotherapeutics：the study of the use of drug.④生药Pharmacognosy(sources of drugs：plants,animal,mineral,microbes,synthetics)；⑤Toxicology毒理 半衰期t1/2( half-life): the time required for the plasma concentration of a drug to be reduced by 50%. ED50(half effective dose): the dose of a drug that is effective for 50% of the population exposed to the drug. LD50(half lethal dose): the dose at which death occurs in 50% of subjects. 治疗窗Therapeutic index=TD50/ED50: The ratio of the dose producing a specified toxic effect in 50% of the test population to the dose producing a specified desired effect in 50% of the population tested.TI越大越安全有效 前药Prodrug：Metabolism often results in inactivation of the drug. Some drug which were activated by metabolism. 首过效应First pass effect：Drugs that are absorbed from the gastrointestinal tract into the bloodstream go first to the liver via the portal vein. Once there，they may be metabolized so rapidly that most of the drug is inactivated before it can reach its site of action. This loss is called~ 生物利用度Bioavailability is the relative rate and extent to which an administered drug reaches the general circulation( this ih especially important when a drug is administered orally).影响BA：solubility of drug in the stomach，diretary patterns，tablet size，quality control in manufacturing and formulation. 受体Drug receptor：A protein macromolecule produced by the body that was designed by nature to interact with an endogenous molecule，but which will also interact with a drug molecule，if it has the correct chemical structure.激动剂Agonist：Has intrinsic activity α=1；拮抗剂Antagonist：