Module 11 - Case Study

Question 1

What is the mechanism of action of tracrolimus? How does it prevent graft rejection?

Answer 1

Tacrolimus is an immunosuppressant drug which reduces T-cell proliferation and cytokine production.
This serves to prevent transplant rejection.

Question 2

What does an increase in serum creatinine suggest?

Answer 2

Creatinine is a normal metabolic product of muscles, which is cleared by the kidneys.
Accumulation suggests kidney impairment.

Question 3

What drug suggested by Dr. Phil could hav accounted for a drug interaction?

Answer 3

St. John’s wort - used to treat depression also induces CYP3A4 - which metabolizes tacrolimus.
Also, St. john’s wort can interact with anxiolytic lorazepam and cholesterol lowering rosuvastatin
This combination can lead to kidney damage

Question 4

What is the significance of the delay in reaction from when Tracy began taking the drugs to when his tacrolimus concentration began to drop?

Answer 4

Enzyme induction is a delayed process, and as such, it would take 2-10 days before the effects of enzymatic induction manifested.

Question 5

Why is Tracey experiencing these symptoms?

Answer 5

The lack of excretion of drugs and toxins by the kidneys.

Excessive drinking also has negative effects on kidney function.

Question 6

What should be done to save Tracy?

Answer 6

The use of St. John’s Wort should be discontinued.