Friday, October 22, 2010

Nonsteroidal antiinflammatory drugs (NSAIDS)

A recent review article on nonsteroidal antiinflammatory drugs (NSAIDS) taught me and reminded me of some important facts with these drugs.
  • COX-2 inhibitors such as celecoxib (Celebrex) increase the risk of heart attack by multiple mechanisms. The authors of this review mention the effect of raising blood pressure, altering endothelial function, and dysrhythmias. They did not mention, however, the concept that by preferentially blocking COX-2, these drugs might be pushing molecular precursors towards COX-1 and are hence prothrombotic. (See Bing and Lomnicka, JACC 2001)
  • If you are taking aspirin to prevent heart attacks and ibuprofen for your knees, headache, or whatever, you should ALWAYS take the aspirin at least two hours prior to the ibuprofen. This has to do with the receptors on the platelets which might be blocked by ibuprofen making the aspirin useless! Since aspirin's effect is permanent for the platelet even after the drug is gone, taking the aspirin before the ibuprofen will make sure you get the benefit of both drugs.
  • For people taking ACE inhibitors for blood pressure, NSAIDS may reduce or eliminate the blood-pressure lowering effect of your ACE inhibitor. This is because blocking the renin-angiotensin system (which is what ACE inhibitors do) causes your kidney to be more prone to salt and water retention (which NSAIDS can cause in anyone).
  • As noted above, since NSAIDS can cause salt and water retention, people with heart failure should not take these drugs unless discussed with their doctor.
  • Believe it or not, aspirin is not recommended for the prevention of heart attacks in people at very low risk of having a heart attack. This is because aspirin slightly increases the risk of having a hemorrhagic stroke or a GI bleed and if your risk of heart attack is already very low, the benefit of aspirin is minimal. Also, if you are going to take aspirin the recommended dose is 81 mg (one baby aspirin) since higher doses increase the risk of bleeding but do not appear to decrease the risk of heart attack.
  • Enteric coated aspirin has not been shown to decrease GI bleeding. The risk of GI bleeding is thought to come mostly from the effect on platelets through systemic effects, not from local irritation of the pill on the stomach/intestinal lining.

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