T36 Pharmacodynamics

specificity

specificity

drug interacts with only one molecular target

selectivity

preference for particular target (tightness)

Pharmacophore

position involved in antibacterial activity

majority of targets of drug action

protein receptors

drug acts as ______

ligand

agonist gives/doesn’t give response

gives

drug can act as agonist/antagonist to receptor

both

peripheral transmitters

autonomic nervous system

parasympathetic main neurotransmitter

acetylcholine

sympathetic main hormone

norepinephrine

sympathetic

fight or flight

parasympathetic

rest and digest

acetylcholine (ACh)

autonomic ganglions, parasympathetic, skeletal muscle, NMJ

Myasthenia gravis

low ACh → muscle can’t contract

Alzhemier’s disease

CNS, caused by decreased ACh → need agonist

Parkinson’s disease

CNS, too much ACh → need antagonist

Antidepresents ______ Norepinephrine levels

increase

dopamine

movement, mood, drug abuse, nausea

5-HT (Serotonin)

hallucination, sleep, mood, appetite, n/v

drugs that increase serotonin

antidepressants

drugs that inhibit serotonin

anti-emetics (reduce nausea)

main drug receptors

ligand-gated ion channels, g-protein-coupled receptors

fastest channel

ligand-gated ion channel

ligand-gated ion channel has ______ receptor and causes ______ to ______ cell

GABA; chloride; enter

g-protein coupled receptor process

ligand bind to receptor → g protein bind to second messengers (cAMP) → activate protein kinase → effector

epinephrine leads to

vasodilation, muscle contraction

what controls voltage-gated sodium channels

local anesthetic, tetrodotoxin

Zidovudine (AZT)

HIV drug

false substrate produces

abnormal metabolite

prodrug produces

active drug

omeprazole is drug for ______ and inhibits ______

peptic ulcer, proton pump

ceiling

maximum, efficacy, how good drug can bind to target

ED50

dose required to produce 50% of maximal effect (potency)

agonist curve

reach maximum right away

partial agonist curve

reach ED50 right away

high potency needs ______ ED50

low

which is more important (potency & efficacy)

efficacy

antagonist

zero activity

inverse agonist

negative activity

spare receptor

fraction of receptors are needed

therapeutic index

toxic dose 50% / effective dose 50%

if desired effect and adverse effect curves are close

bad

toxicity is measured by

lethal dose 50%

drugs with narrow Therapeutic index have ______ Therapeutic window

narrow

receptor upregulate

increased sensitivity

receptor downregulation

prolonged use

enhanced drug effect

additive (1+1=2), synergistic (1+1>2)

indifferent drug interaction

1+1=1

reduced drug effect

antagonistic (1+0=0)

competitive inhibition

antagonist bind to receptor that agonist binds

noncompetitive inhibition

antagonist binds to other site

in the presence of competitive antagonist need to ______ dose

increase

competitive inhibition graph

shift horizontally

noncompetitive inhibition graph

shift vertically

physiological antagonism

bind to completely different receptors and cause opposite effect

chemical antagonism

antidote

tolerance

effect of drug gradually diminishing when given continuously

tachyphylaxis (acute tolerance)

rapidly diminishes

drug resistance

used for microbes (not humans)

intolerance

toxic effect of drug after long usage