Principles of Pharmacology- Lecture 1 Flashcards
Affinity
potential for drug receptor binding
“receptor binding”
Receptor
binding site with biological effect
“site”
Intrinsic activity
capacity to produce biological effect
Agonists
substances that stimulate a receptor to produce a physiologic reaction; have both affinity and intrinsic activity
Antagonists
substances that oppose or interfere with the activity of a receptor and its endogenous substrate without producing a physiologic effect itself; antagonists have affinity but lack intrinsic activity
Allostery
a stereospecific phenomenon whereby a bound ligand influences specificity of a second site
Efficacy
Affinity x Intrinsic activity ; dose independent
EC50
effective concentration in 50% of subjects
ED50
effective dose in 50% of subjects
IC50
inhibitory of 50% of subjects
Hypersensitivity
result of chronic antagonism
Maximum Dose
min. amount of drug producing maximum therapeutic effect
Partial Agonist
low intrinsic activity with potency and affinity within therapeutic range
Pharmacodynamics
Drug-> Body
focuses on biochemical and physiological effects of drugs and their mechanisms of action; potency, efficacy, affinity and toxicity are key measures
Pharmacokinetics
Body → Drug (ADME)
Pharmacotherapeutics
Drug—> Disease
Posology
study of drug dosing
Potency
biological response to a given dose
Resistance
loss of pharm. effect
Selectivity
ability to produce a desired effect versus adverse effect
Specificity
ability to act at a specific receptor
Tachyphylaxis
rapidly decreasing therapeutic response
Teratogenesis
congenital malformation
Bioavailability
amount of active drug reaching target tissue ; does not directly relate to drug potency
Therapeutic index:
: LD50:ED50 or TD50:ED50
DPA
diagnostic pharmaceutical agent
TPA
therapeutic pharmaceutical agent
Drug Types
Supportive: glucose Supplemental: Insulin Prophylactic: low dose aspirin Symptomatic: olopaptidane Diagnostic: florescein Therapeutic: methotrexate
PHYSIOLOGIC RECEPTOR MOTIFS
Nuclear: e.g. steroids, hormones
G-protein-coupled: e.g. AChM, rhodopsin
This is the MOST COMMON receptor type targeted by ophthalmic drugs
Ion channels: e.g. GABAA, AChN, glutamate
Enzymatic: e.g. insulin, epidermal growth factor
Calcium release: calcineurin, nitric oxide synthase
Types of Agonists
Direct Indirect Mixed Inverse Partial
Antagonists Binding Integrity
Reversible
Irreversible
Antagonists binding site selectivity
Competitive (same as endogenous agonist)
Non-competitive (allosteric)
Uncompetitive (allosteric binding in presence of substrate slows ligand dissociation and response rate) (requires presence of agonists)
Antagonists Mode of Action
Biological: e.g. PCN
Chemical: e.g. Alka Seltzer, chelators
Physiological: e.g. ACh, E, His
