Differences Between NSAIDs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most widely prescribed groups of medication in the United States. NSAIDs are relatively inexpensive and are frequently the first line of medication used to relieve pain and reduce inflammation. These medications are particularly useful not only because they effectively decrease pain, but they also help control swelling and inflammation.

Are there any important differences between these medications?

NSAIDs vary in their potency, duration of action, and the way in which they are eliminated from the body. Another important difference is their ability to cause ulcers and promote bleeding. The more an NSAID blocks Cox-1, the greater is its tendency to cause ulcers and promote bleeding. Indomethacin, ketoprofen and piroxicam appear to have the highest prevalence of gastrointestinal side effects, while ibuprofen (lower doses) and diclofenac appear to have lower rates.

Choice of NSAID for chronic and disabling inflammatory joint diseases like rheumatoid arthritis and osteoarthritis is governed by age, diagnosis, degree of severity, relative gastrointestinal safety, tolerability, and relative efficacy in the given situation.

It is a common misconception that all NSAIDs are therapeutically equally efficacious and any one of them could be used for the given indication. Use of multiple NSAIDs should be discouraged. An agent with comparatively less gastrointestinal (GI) side effects like ibuprofen and diclofenac should be preferred in place of indomethacin, piroxicam, or naproxen, which are more gastrotoxic. In conditions where diagnosis is uncertain, the medicine should be empirically chosen and given for a week or so and if the response is adequate it should be continued until side effects mandate its withdrawal. Ankylosing spondylitis responds better to a particular NSAID like indomethacin. It is probably related to its stronger inhibition of prostaglandin synthesis.

Aspirin is a unique NSAID, not only because of its many uses, but because it is the only NSAID that is able to inhibit the clotting of blood for a prolonged period (4 to 7 days). This prolonged effect of aspirin makes it an ideal drug for preventing the blood clots that cause heart attacks and strokes. Most other NSAIDs inhibit the clotting of blood for only a few hours.

The major NSAIDs of potency comparable to opioids are diclofenac and ketorolac. Moderate postoperative pain, for example, may be managed using these medications. The overall analgesic effect of 30 mg of ketorolac is equivalent to that of 6 to 12 mg of morphine. Efficacy has been demonstrated for postsurgical pain including oral, orthopedic, gynecologic, and abdominal procedures. Efficacy for acute musculoskeletal pain has also been shown. Ketorolac causes ulcers more frequently than any other NSAID and is, therefore, not used for more than five days.

Naproxen provides effective relief in acute traumatic injury and for acute pain associated with migraine, tension headache, postoperative pain, postpartum pain, pain consequent to various gynecologic procedures, and the pain of dysmenorrhea.

None of the NSAIDs is best for all of the criteria that are considered when selecting a drug. Although NSAIDs have a similar mechanism of action, persons who do not respond to one NSAID may respond to another.