PSYC62H3 Chapter 3: Chapter 3
Document Summary
Process involved in the movement of drugs within biological systems. Looks at drug in respect to absorption, distribution, binding in tissues, metabolic alterations, and excretion from the body. In order for drug to reach site of action, it has to pass through several biological membranes. depends upon the drug"s site of action and the route of administration (ex: orally administered drugs have to pass through all the biological membranes whereas intravenous injections don"t have to go through the biological membranes) Salt form of drug, particle size of the dosage form, and suspending agent used can affect the degree of absorption. The greater the differential concentration of the molecules on the two sides, the more readily the drug will diffuse into the body: lipid solubility. Most important factor in a drug"s ability to pass through these membranes. As lipid solubility increases, the better absorption from the blood, the faster it gets to the brain to exert its psychoactive effects.
