Q: FDA's new product labeling warns about liver toxicity with excessive doses of acetaminophen (e.g., Tylenol). What about the new labeling for OTC NSAID products?
A: The proposed new NSAID labeling calls attention to the risk of NSAID-related stomach bleeding.
As with acetaminophen, the FDA wants product labels to use bold or fluorescent type for further emphasis.
OTC NSAIDs help relieve pain, inflammation, and fever. Products include aspirin, ibuprofen (e.g., Advil, Motrin IB, Midol IB, Nuprin), naproxen (Aleve), and ketoprofen (Actron, Orudis KT).
The upcoming label will highlight the potential for NSAID-related stomach bleeding in those who:
-are over age 60
-have had prior stomach or duodenal ulcers or bleeding
-take a blood thinner such as warfarin (Coumadin)
-take more than one product containing an NSAID
-drink moderate amounts of alcohol
-take the product for a longer time than directed
Between 1998 and 2001, the FDA's Adverse Event Reporting System turned up a total of 279 cases of stomach bleeding associated with OTC NSAID products: 197 cases for ibuprofen, naproxen, and ketoprofen, and 82 cases for aspirin.
That's a tiny number considering the widespread use of these products, and it's likely that many more cases went unreported.
OTC NSAIDs, as well as most prescription NSAIDs, are non-selective. That means they block both COX-1 and COX-2 enzymes.
Blocking COX-2 helps relieve pain, inflammation, and fever. This is the therapeutic effect produced by NSAIDs and the reason they are taken.
However, COX-1 and COX-2 lead to a number of benefits, and blocking them may cause some detrimental effects.
For one thing, COX-1 is involved in protecting the stomach lining against damage from the strong acid it secretes. Blocking it paves the way for stomach injury and bleeding, and in some cases, ulcers. (Blocking COX-1 thins the blood, which increases this bleeding risk.)
That's what prompted FDA's new NSAID label proposal.
Both COX-1 and COX-2 are involved in kidney-protective effects. Blocking either one may compromise kidney function, promote fluid retention (edema), raise blood pressure, and boost cardiovascular risk.
That's the reason for the long-standing recommendation to use NSAIDs cautiously in those with high blood pressure or congestive heart failure.
According to the FDA, NSAID-related acute kidney failure is rare. The risk is higher in those with chronic kidney disease, congestive heart failure, liver cirrhosis with ascites (fluid in the abdomen), or low blood volume such as that associated with dehydration.
Consumer groups are urging FDA to include label statements about these risks in addition to that for stomach bleeding, but some OTC manufacturers are resistant to further label warnings.
My view: These other potential adverse effects have been known for decades, and the new labeling should also address them.
That said, OTC NSAIDs appear to be safe for most people when taken as directed and with proper cautions in mind.
Richard Harkness is a consultant pharmacist, natural medicines specialist, and author of eight published books.