An older adult client brought to the emergency department for bloody stools has been taking warfarin (Coumadin) post stroke. Initial diagnostic lab work reveals warfarin to be within therapeutic range

Question

The daughter asks why the client has bloody stools if the lab work is normal. Which responses by the nurse are appropriate?
1. "Liver function declines during the aging process."
2. "Decreased liver function results in decreased plasma proteins."
3. "Decreased plasma proteins result in more free drug circulating."
4. "Decreased plasma proteins lead to more binding sites, resulting in lower concentrations of drugs such as this one."
5. "Higher levels of this drug are able to enter the blood–brain barrier, resulting in the toxic effects of bleeding."

Answer 1

Correct Answer: 1,2,3
Rationale 1: Liver function declines during the aging process.
Rationale 2: As liver function declines, so does the production of plasma proteins.
Rationale 3: As the production of plasma proteins declines, an increase in highly protein-bound drugs results in higher concentrations of free drug.
Rationale 4: Decreased plasma proteins lead to fewer binding sites, resulting in higher, not lower, concentrations of free drug.
Rationale 5: The decrease in liver function and plasma proteins may cause the adverse effects of bleeding and bloody stools. It does not have anything to do with the blood–brain barrier.
Global Rationale: Liver function declines during the aging process. As liver function declines, so does the production of plasma proteins. As the production of plasma proteins declines, an increase in highly protein-bound drugs results in higher concentrations of free drug. Decreased plasma proteins lead to fewer binding sites, resulting in higher, not lower, concentrations of free drug. The decrease in liver function and plasma proteins may cause the adverse effects of bleeding and bloody stools. It does not have anything to do with the blood–brain barrier.