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