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Prerequisite basic sciences
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vs aspirin for pediatric patients p. 498
free radical injury and p. 213
hepatic necrosis from p. 250
for osteoarthritis p. 476
tension headaches p. 536
toxicity effects p. 498
toxicity treatment for p. 249
acetaminophen and p. 498
So, during inflammation, your immune cells use an enzyme called phospholipase A2 to take membrane phospholipids and make a 20 carbon polyunsaturated fatty acid, called arachidonic acid.
Arachidonic acid is a substrate for an enzyme called cyclooxygenase or COX.
The enzyme cyclooxygenase exists in two different isoforms: COX-1 and COX-2.
COX-1 is a constitutive enzyme, meaning that it’s always active, while on the other hand, COX-2 is an inducible enzyme, meaning that it must be turned on to function. This is usually triggered by immune cells and vascular endothelial cells during inflammation.
Both enzymes produce prostaglandin E2 (PGE2) and prostacyclin (PGI2), which cause vasodilation and attract different immune cells to the area.
They also act on neurons that detect pain, called nociceptors, and make them more sensitive to stimuli by lowering their threshold for activation.
Prostaglandin E2 also has other effects like causing uterine contractions, decreasing the secretion of acid, and increasing the production of protective mucus in the stomach.
Alright, now let’s focus on acetaminophen. Acetaminophen is administered orally, rectally, or intravenously; and it works by reversibly inhibiting COX in the central nervous system, thereby decreasing production of the prostaglandins that cause fever and pain.
Acetaminophen (Paracetamol) is a medication used to relieve pain and reduce fever. It is usually taken orally, but can also be given intravenously. Acetaminophen is one of the most common medications used and is generally considered safe when taken as directed. However, acetaminophen can cause serious liver damage if too much is taken or if it is taken with certain other medications such as pexidartinib.
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