MacroPhage

Pharmacodynamics in infant:  Pharmacodynamics in adults: Pharmacodynamics in adults change with age including receptor alterations, impaired signal transduction and decreased homeostatic regulation. Adverse Effects in infants: Adverse Effects in adults: Incidence of Adverse effects reactions  increases by age  as elderly receive more medicines. For patients > 50 years: a) Adverse effects reactions are  5% of occurrence   for  1-2 given medicines . b) Adverse effects reactions increase to  20% of occurrence   for  more than 5 given medicines . And Thnx

As we know before that Absorption, Distribution, Metabolism and Elimination are related to Pharamacokinetics so, we will compare the previous processes between infants and adults.  Absorption: Distribution: *: The less lean body mass , the more percentage of fat and the more the drug can diffuse into tissues and prolong its action . *: The less serum albumin , the more percentage of free drug in the blood . *: The more alpha acid glycoprotein , the more distribution of drug in body .  Factors affecting distribution of drug: a)     Size of water body compartment. b)     Plasma protein binding. c)     Development of BBB. d)     pH and composition of body fluids. e)     Blood flow and tissue specificity for receptor site. Size of water compartment: 1)     Is high ranging from 65% in older children to 80% in neonates . 2)     The more water content, the higher dose given to patient. 3)      There are some drugs, their dose is calculated based o

Pharmacodynamics Definition Pharmacodynamics are what a drug does to the body. Drug: -Target Site ( Therapeutic Effect ) -Other Sites ( Adverse Effects )   They are the studies of the therapeutic effects, the adverse effects and the mechanism of action of each effect. MECHANISM OF ACTION OF DRUGS: - ·         Receptor-mediated mechanisms ·         Non-receptor-mediated mechanisms Ø Receptor-mediated mechanisms Receptors: •          Are protein macromolecules that combine chemically with small molecules (ligands) and produce physiological regulatory functions. They may be extracellular or intracellular. ·          Ligand is any chemical substance that combines with the receptors and produce an effect. ·          Ligands that activate the receptors are called agonists, ligands that combine the same site without causing activation are called antagonists. ·          The receptor site or recognition site for a drug has a high and selective affinity for the

1.        Majority of drugs cross biological membranes primarily by : a)        Passive diffusion b)       Facilitated diffusion c)        Active transport d)       Pinocytosis 2.        Diffusion of drugs across cell membrane : a)        Is dependent upon metabolic activity of the cell b)       Is competitively inhibited by chemically related drugs c)        Is affected by extent of ionization of drug molecules d)       Exhibits saturation kinetics 3.       The most important factor which governs diffusion of drugs across capillaries other than those in the brain is: a)        Blood flow through the capillary b)       Lipid solubility of the drug c)        pKa value of the drug d)       pH of the medium 4.       Active transport of a substance across biological membranes has the following characteristics except: a)        It is specific b)       It is pH dependent c)        It is saturable d)       It requires metabolic energy 5.