Ch 2 2 Pharm

  1. Topical
    • Poorly absorbed beyond epidermis
    • Ex: antibiotic for cutaneous infection, anti-inflammatory steroid; eye drops
  2. Transdermal
    • Applying drug to skin with intent that they will be absorbed through the dermal layers into the subcutaneous tissue or peripheral circulation
    • Slow controlled release of drug into body, effectively maintaining plasma levels of the drug
    • Ex: nitroglycerin, motion sickness, hormones, local anesthetics, opioid analgesics, and nicotine patches
    • Also used by Iontophoresis and phonophoresis
  3. Bioavailability
    • Percentage of drug that reaches the blood stream
    • Dependent on route administered (Ability to cross membrane barriers)
  4. Passive diffusion
    • Due to gradients
    • Most medications are lipid soluble
  5. Active transport
    • Energy expended
    • Carrier specific
    • Ability to transport against gradient
  6. Facilitated diffusion
    Protein carrier to assist drug across membrane; does not use energy
  7. Endocytosis
  8. Drug distribution based on
    • Tissue permeability
    • ----ability to pass through membrane
    • --------Larger non-lipid soluble compounds usually stay where they are
    • Blood flow
    • ----If a drug is circulating the blood stream it has greater access to highly perfused tissue
    • --------Ex: vascular disease/ diabetes
    • Binding to plasma proteins
    • ----Some drugs bind irreversibly to proteins to blood such as albumin
    • --------Drug bound to protein is not bioavailable
    • Binding to sub-cellular components
    • ----Drugs bound within specific cells cant be distributed throughout other fluid compartments
    • Volume of distribution
    • = Drug delivered
    • Concentration in plasma
    • <42L drug retained in bloodstream
    • >42 drug in tissue
    • Drug Storage Locations
    • Adipose
    • ---- most common Bc most medications are lipid soluble (passive diffusion)
    • Bone
    • ----Storage for toxic agents and heavy metals
    • --------Gold in RA
    • Muscle
    • ----Binding to muscle leads to long term storage
    • Organs
    • ----Liver, kidney
  9. Adverse effects of drug storage
    • Local tissue damage
    • Drug not available to area in need
  10. Controlled release drug delivery
    • Timed-release
    • Extended-release preparations
    • Decrease dosages through day, prevent large fluctuation of drug in plasma, sustain plasma levels throughout night
    • Ex: beta blocker, Ca channel blockers, narcotic analgesics (morphine and hydromorphone), antiparkinsonism medication containing L-dopa
  11. Implanted systems drug delivery
    • implanted under skin in abdomen
    • releases small, measure dose of drug on preprogrammed schedule
  12. Cell and tissue targeting drug delivery
    • Specific drug going to specific tissue to prevent adverse effects to other tissues
    • Seen in cancer drugs
  13. Biotransformation
    Changes in drug after administration (prodrug)
  14. Metabolite
    • Altered version of the original compound
    • Inactive or has reduced level of pharmacological activity
Card Set
Ch 2 2 Pharm
Ch 2 2 Pharm