Acquired platelet disorders Flashcards
1
Q
How can a platelet disorder be acquired? Name the 2 ways and explain how they arise.
A
A prolonged continuous usage of aspirin.
- Aspirin irreversibly inhibits COX-1 and therefore TxA2. Decreased TxA2 means that platelet aggregation is impaired, meaning that a stable plug cannot be formed and bleeding time is prolonged.
- Aspirin takes its effects for 7-10 days (normal lifespan of platelets) but with prolonged use, it causes a bleeding disorder.
Due to chronic renal failure
- These patients have increased levels of phenolic acid which impairs platelet activation and also increased levels of nitric oxide which impairs platelet adhesion.
2
Q
How are these disorders treated?
A
- Stop the offending drug.
- Treat the renal failure.
3
Q
What is key when diagnosing these disorders?
A
- History, drug screen.
- Renal failure will be apparent.