Pharmacokinetics vs. Pharmacodynamics

• Pharmacokinetics 


  Drug movement
• Pharmacodynamics


  Mechanism of Action
• Pharmacokinetics

  What the body does to the drug?
• Pharmacodynamic

  What the drug does to the body?
• Pharmacokinetics

  • absorption
  • distribution
  • metabolism
  • excretion
• Pharmacokinetics

  Absorption - site of administration to the bloodstream
• Pharmacokinetics

  Distribution - site of absorption to the site of action
• Pharmacokinetics

  Metabolism (Biotransformation - liver): active drug dose - enzyme - inactive drug dose - kidney
• Pharmacokinetics

  Excretion - kidney - urine
• Drugs can be taken without food:

  • Penicillin
  • Cytoprotectants
  • PPI
• Drugs can be taken with food:

  • NSAIDS
  • Corticosteroids
  • Acidic drugs
• Pharmacokinetics

  First Pass Effect - reduction in the concentration of a drug due to its metabolism by the liver after oral administration and before it reaches systemic circulation.
• First Pass Effect

  Drug - PO - GI - Liver - Metabolism
• Route of Administration

  PO - with first pass effect
• Route of Administration

  Parenteral

  • IM - 90 degrees
  • SQ - 45 degrees
  • Obese SQ - 90 degrees
  • IV and ID - 10 to 15 degrees
• Route of Administration

  Per rectum - position: left side lying, upper knees flexed
• Route of Administration

  Otic

  Grow Up, Little Down

  • adult - up and back (pinna)
  • children below 3 year ol - down and back (pinna)
• Route of Administration

  Ophthalmic - press the nasolacrimal duct
• Route of Administration

  Parenteral - 100% bioavailability
• Route of Administration

  Intraosseous (bone) - proximal tibia, iliac crest
• • Alkaline Drugs (Atropine, Cocaine, Quinidine): Best managed with an acid ash diet (e.g., cranberries, plums, prunes) to acidify urine.
  • Acidic Drugs (Salicylates, Phenobarbital, Tranexamic Acid): Can be better excreted with an alkaline ash diet (e.g., fruits, vegetables, milk) to alkalize urine.
  • Anti-Gout Drugs (Colchicine, Allopurinol, Probenecid): Benefit from an alkaline ash diet to reduce uric acid levels and prevent gout flare-ups.
• Diuretics

  Loop (Furosemide) - Hypo Na, Cl, K - ototoxic
• Diuretics

  Thiazide (Hydrochlorothiazide) - hypo Na, Cl, K
• Diuretics

  K Sparing (Spironolactone) - Hypo Na, Cl
• Diuretics

  Osmotic (Mannitol) - Hypo Cl, K
• Diuretics

  Carbonic Anhydrase Inhibitor (Acetazolamide) - Hypo Na, Cl, K
• Diuretics

  • Loop
  • Thiazide
  • K sparing
  • Osmotic
  • Carbonic Anhydrase Inhibitor
• Diuretics

  Furosemide - ototoxic
• Diuretics

  Hydrochlorothiazide - increase uric acid
• Diuretics

  Spironolactone - Hyperkalemia
• Diuretics

  Mannitol - Hypernatremia
• Diuretics

  Acetazolamide - acidosis
• Pharmacodynamics

  Receptor Interaction

  • Agonist - bind receptor = (+) response
  • Antagonist - bind receptor = block
• Pharmacodynamics

  Agonist - "mimetic"

  sympathetic response - adrenergic

  adrenergic agonist - sympathomimetic

  cholinergic agonist - parasympathomimetic
• Pharmacodynamics

  Antagonist - "lytic" "blocker"

  parasympathetic response - cholinergic

  adrenergic antagonist - sympatholytic

  cholinergic antagonist - parasympatholytic
• Adrenergic Receptors

  Alpha 1 - Vasoconstriction, mydriasis

  Alpha 2 - Vasodilation

  Beta 1 - Increased Heart Rate and Contractility

  Beta 2 - Bronchodilation, Smooth muscle relaxation, Hyperglycemia, Aqueous humor production
• Adrenergic Agonist

  Epinephrine - A1, B1, B2
• Adrenergic Agonist

  Norepinephrine and Phenylephrine - A1
• Adrenergic Agonist

  Beta 1 agonist - inotropic drugs (dopamine and dobutamine)
• Adrenergic Agonist

  Beta 2 agonist - salbutamol, albuterol