What is the antidote for acetaminophen overdose and How does

What is the antidote for acetaminophen overdose?. and How does aspirin work on platelets? And why is it more effective than other NSAIDS? Please cite references

Solution

N-acetylcysteine (NAC) is an antidote to acetaminophen overdose and is most effective within 8 hours acetaminophen ingestion. It prevents liver failure however; it should be given in primary stages.

Aspirin causes the acetylation of critically important amino acid serine⁵²⁹ of platelet cyclooxygenase (COX) which causes inhibitory action of platelets and leads to antithrombotic action. This phenomenon stops the access of arachidonic acid (substrate) to the catalytic site of the enzyme at tyrosine³⁸⁵ and which in turn causes an inhibition of platelet-dependent thromboxane formation and this inhibition is irreversible.

Aspirin is more effective than other NSAIDS due to the fact that aspirin is the only NSAID that inhibits COX-1 irreversibly and it is for this reason it is more advantageous for cardiovascular patients as it prevents platelet aggregation and in turn prevents clot formation and on the other hand all other NSAID inhibit don’t block the COX-1 or COX-2 irreversibly. The irreversible effect is referred to the fact that antiplatelet effect does not wear off until new platelets are generated (7 days). It may be kept under consideration that all NSAIDs block either the enzyme COX-1 or COX-2, or both. COX-1 is the enzyme that shows platelet activity and defensive functions in gastrointestinal tract and COX-2 induces inflammation, pain, and fever. The NSAID may have different effects and side effects depending on which enzyme they act.

Reference: Schrör K. Aspirin and platelets: the antiplatelet action of aspirin and its role in thrombosis treatment and prophylaxis. Semin Thromb Hemost. 1997;23(4):349-56.