03 Dose



peak effect of morphine higher: morphine more effecacious
peak effect at lower dose: morphine more potent
Dose-Response


quantal: if drug eliminate headache

EC50 or ED50: effective concentration or dosage. Dose needed to get 50% Emax

log of dose on X: S shaped curve, better for E50
Potency

same maximum effect
Efficacy

Competitive Antagonist

e.g. beta agonist and beta blocker at same time
beta blocker competes with beta agonist. At higher dose, beta agonist outcompete beta blocker
Emax same: how much effect beta agonist can stimulate one each receptor is same
Noncompetitive antagonist

bind to beta receptor, change its shape and make it bind agonist less
increasing dose cannot overcome effect
same thing as removing beta receptor from system
E50 same
Spare receptors


add noncompetitive antagonist, should lower Emax but shifts it right instead
reason: spare receptors activated with less potency binding
eventually with high dose noncompetitive antagonist, lower Emax, antagonize also spare receptors
Partial Agonists



increasing partial agonist dose: competitive binding

response instead of percent

clomiphene: activate estrogen receptors but not as much as estrogen
Quantal Dose

ED50: dose required for 50% pts response

lethal dose and toxic dose

higher therapeutic index: more apart LD50 and ED50, wider therapeutic window


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