Medical Edge Newspaper Column

Comparing NSAIDs And Other Pain Relievers

Jan. 30, 2006
DEAR MAYO CLINIC:
I had orthopedic knee surgery about eight months ago and have been taking the anti-inflammatory drug diclofenac (75 mg, twice a day) since then. My doctor said I could try ibuprofen instead (200 mg, four times a day). Assuming that the two dosage totals are equivalent, I would like to know which drug has the greater ability to reduce my stiffness and pain -- it seems I am achier since taking the ibuprofen. I also want to know which one is harder on the stomach and which one is safer overall.

ANSWER:
Many nonsteroidal anti-inflammatory drugs are available, including ibuprofen (brand names Motrin and Advil) and diclofenac (Voltaren), which you mention. These medications inhibit chemicals in the body associated with pain and inflammation.

From many studies that have been conducted to determine which NSAID works best, ibuprofen and diclofenac generally have been shown equally effective. However, many patients find one drug more effective than the other. This may result from subtle variations in how the medications work, combined with genetic differences among individuals.

All medications have side effects, and NSAIDs are associated with potentially serious ones, such as fluid retention, increased blood pressure, kidney damage and irritation of the upper gastrointestinal tract. The GI problems, which include abdominal pain and black tarry stool (suggesting digested blood), occur because NSAIDs also inhibit a chemical that protects the stomach. If these symptoms develop, stop taking the drug and seek medical care immediately.

Ibuprofen and diclofenac appear to have about equal risks of GI side effects. Diclofenac is available in combination with another drug (misoprostol) that can help protect the stomach lining; the combined medication is known as Arthrotec. Please note, however, that misoprostol can produce diarrhea.

Other drugs are also available that, when taken with NSAIDs, can reduce the likelihood of GI irritation or bleeding. These side effects may be curbed just by taking NSAIDs with food or milk.

Estimating equivalencies between one drug and another can be tricky. Ibuprofen is typically taken by adults in doses of 200 mg to 800 mg, three to four times per day; and diclofenac can be taken in doses of 25 mg to 75 mg, two to three times per day. A good rule of thumb for NSAIDs is to use the lowest effective dose for the shortest possible duration.

It is a good idea to consult with your doctor on your response to these medications and the best dose for you. People should check with their doctor before taking any NSAID on a regular basis, especially if they are over 65 or have respiratory, cardiac, kidney or GI problems.

Certain NSAIDs, known as COX-2 inhibitors, are less likely to cause gastric distress. However, they are more likely to be associated with serious cardiovascular events such as heart attacks and strokes. For that reason, all but one COX-2 inhibitor -- celecoxib (Celebrex) -- has been withdrawn from the market. And the U.S. Food and Drug Administration is calling for Celebrex to carry a warning label that cites the possibility of cardiovascular events and other potential side effects. Other NSAIDs are coming under scrutiny for the same concern.

Acetaminophen (Tylenol), which is not an NSAID, reduces pain without causing GI side effects. Unlike NSAIDs, acetaminophen does not reduce inflammation. Also, acetaminophen has side effects, such as the risk of liver damage if taken in doses exceeding 4,000 mg a day.

-- Terrence L. Trentman, M.D., Pain Clinic, Mayo Clinic, Scottsdale, Ariz.