PK

  1. Describe the 2 separate processess of dialysis.
    • 1. Diffusion = uses a concentration gradent (high to low)
    • 2. Ultrafiltration = water being pulled off; the greater the surface area, the higher the efficiency of the filter (flow rate for dialysate)
  2. What are the drug characteristics that affect dialysis removal?
    • molecular weight
    • water/lipid solubility
    • plasma protein binding
    • volume of distribution
    • inherent clearance (route and rate)
  3. What size drug molecules tend to be readily eliminated by dialysis?
    small drug molecules (< 500 daltons)
  4. What size drugs have a decreased ability to pass through the semi-permeable membrane in low flux filters?
    moderate molecular mass (500-1000 daltons)
  5. What type of drugs still have sufficient dialysis clearance to require post-dialysis replacement doses?
    moderate molecular mass (500-1000 daltons)
  6. What type of drugs require high-flux filters for removal?
    large molecules (>1000 daltons)
  7. A drug that tends to remain in the blood has what kind of solubility?
    lipid solubility
  8. What happens to drugs that have a high degree of water solubility?
    They tend to partition into water-based dialysis fluid
  9. What type of drug molecules are able to pass through the pores in a semi-permeable membrane?
    Unbound
  10. What type of drugs are prone to better dialysis clearance?
    Drugs that are NOT highly plasma protein-bound have a high free fraction of drug in the blood.
  11. Where are medications with a high Vd mostly located?
    At tissue binding sites and not in the blood
  12. Are drugs with a low Vd more or less easily removed by dialysis?
    More easily removed
  13. Determine if the following drugs are more likely or less likely to be removed by dialysis:
    Drug 1: Vd > 2L/kg
    Drug 2: Vd < 1L/kg
    • Drug 1: less likely (not in the blood)
    • Drug 2: more likely
  14. If a drug is primarily eliminated by the kidney, will it have a higher or lower likelihood of being removed by dialysis?
    higher
  15. What are the 3 most common dialysis techniques?
    • HD: hemodialysis
    • CAPD: continuous ambulatory peritoneal dialysis
    • CVVH: continuous venovenous hemofiltration
Author
ch.tyrrell
ID
150718
Card Set
PK
Description
Dialysis
Updated