Lecture 1: Pharmacodynamics Flashcards
Pharmacology
-science of interactions of chemical compounds with biological systems
-mechanisms of drug action
Pharmacodynamics
-study of biochemical and physiological effects of drugs and their mechanisms of action
-correlation of action and effects with their chemical structure
Pharmacokinetics
-study of ADME of xenobiotics
Nature of drugs
-defined by actions (agonists/antagonists)
-act on receptors (except for chemical antagonists and osmotic agents)
-endogenous drugs or xenobiotics
-includes poisons and toxins
-solid liquid or gas
-ions to larger proteins/antibodies/vaccines
-covalent, electrostatic, hydrophobic interactions
-drug shape and rational drug design for receptor specificity
Endogenous drugs
-hormones
-neurotransmitters
Drug receptor
-cornerstone of pharmacology
-explains how organism interacts with drug and initiates chain of biochemical events which results in observed effects
Agonist
the drug whose interaction with the receptor stimulates biological response
Pharmacodynamic Principles
- D+R
- DR complex
- effect
Drug binding
-1st step of PD principles
-orthosteric interactions
-allosteric interactions
orthosteric interactions of drug binding
-agonist
-antagonist
-partial agonist
-inverse agonist
allosteric interactions of drug binding
-positive (PAM)
-negative (NAM)
-activator or inhibitor
SLIDE 15
16 and 17
Inhibitors of metabolism/reuptake of endogenous ligands
-have drug like responses
-MAOIs and SSRIs
-MECH slide 17
Duration of drug action
influenced by receptor and drug
Purpose of drug therapy
-produce characteristic effects of the drug
-drug must achieve good concentrations at site of action
-achieve maximal positive effect of drug while minimizing side effects
No drugs
have only one effect
Influences on drug therapy
-prescribed dose
-administered dose
-concentration at site of action
-drug effects
Drug Specificity
-affinity for receptor
-distribution of receptor
-multiple receptors
-enantiomers
-acute vs chronic effects
ranitidiine vs digoxin and methotrexate
distribution of receptor
amiodarone and clozapine
multiple target receptors
Drugs modify
-cellular function
-normal physio/biochemical function of organ, tissue, cell
Laxative drugs
-increase activity of GI tract
-stimulation
general anesthetics
-decrease activity of cells in CNS
-depression
No drug has a single effect
-usually want one effect “therapeutic effect”
-unwanted side effects esp at higher doses “toxic/side effects”
Sites of drug action
-Where drug acts to initiate chain of events leading to effect
-intra/extracellular and on the cell surface
Extracellular sites of drug action
-neutralization of excessive gastric acid by antacids
-cholestyramine resin reducing cholesterol absorption
Intracellular sites of drug action
-treat infection
-cancer chemotherapy
-hormones like estrogen
Cell surface sites of drug action
-many drugs act by combining with receptors on the cell
-acetylcholine, muscarinic, nicotinic receptors
-Growth factors (EGF/FGF) and GF receptors
-monoclonal antibodies (mABs)
slide 28
slide 28
