PSYC 4035 : Exam 1 Study Guide
Document Summary
Membrane thickness, surface area of membrane, size of diffusing molecule, ionization. Clearance: how much fluid needs to be removed to account for the amount of drug that enters the body. Clearance=drug removed per minute / drug concentration in plasma. Half-life: the time required to remove half of the drug from the body. Therefore, it takes five half-lives to eliminate from the body. Volume of distribution: the volume of fluid necessary to keep drug concentration evenly and needed to dissolve all of the drug in the body, based on plasma concentration. If it is a true physiologic volume, it is related to water in the body. As volume of distribution increases, half- life increases. Most drug diffusion is passive through lipid bilayers, simple diffusion. Facilitated diffusion because the drug comes down the concentration gradient, the energy used is from kinetic energy, therefore no input of energy is necessary.
