Oxaprozin

Cyclooxygenase-2--specific inhibitors are the new NSAIDs on the block. Unlike traditional NSAIDs, which are nonspecific cyclooxygenase (COX) inhibitors, the COX-2 inhibitors selectively block production of pain-mediating prostaglandins while sparing COX-1, which produces gastroprotective prostaglandins.

Patients who take traditional NSAIDs may develop persistent gastrointestinal symptoms; some experts estimate the fraction may approach 50%. This causes more than 10% of all patients on NSAIDs to stop their treatment. COX-2 inhibitors cause less gastrointestinal toxicity, but they still carry a warning about GI effects in their labeling. Dyspepsia remains a problem for many patients who take a COX-2 inhibitor.

COX-2 inhibitors also have a weaker anticoagulant effect on platelets, but they are no more effective at relieving pain and inflammation than the older NSAIDs, and they share the older drugs' renal side effects. The COX-2 inhibitors also cost more.

Experts recommend the COX-2 inhibitors for patients who have a history of or are at risk for gastric ulcers, patients on anticoagulants, and patients taking steroids. Many patients aged 65 years and older fall into these categories, so the COX-2 inhibitors may prove to be the drugs of choice for elderly patients. The COX-2 inhibitors may also have an edge in treating women because they cause less menorrhagia and vaginal bleeding. However, at high doses they may interfere with fetal implantation.

Keep in mind that NSAIDs are adjuvant therapy for rheumatoid arthritis. They should be used in combination with disease-modifying antirheumatic drugs unless the disease is in complete remission.

The two COX-2 inhibitors on the US. market, celecoxib (Celebrex) and rofecoxib (Vioxx), are considered by many experts to have similar safety and efficacy in treating rheumatoid arthritis, although only celecoxib is approved. A third drug in the class, meloxicam (Mobic), is soon to be approved by the FDA. The older NSAIDs are generally similar; price is often the factor in choosing among them.

Women who are pregnant or breast-feeding should avoid treatment with any NSAID. Start elderly patients on lower dosages, and always take into account a patient's hepatic and renal function when picking a dosage. Avoid indomethacin in the elderly because of possible neurologic side effects.

(*.)Cost is based on the average wholesale price for a 100-unit package of the generic formulation, unless otherwise indicated, in the 1999 Red Book.

(**.)Cost is based on the average wholesale price for a 100-unit package, as provided by the manufacturer.

(+.)The comments reflect the viewpoints and expertise of the following sources: Dr. Daniel E. Furst, director, Arthritis Clinical Research Unit, Virginia Mason Medical Center, Seattle Dr. Robert P. Kimberly, director, Arthritis and Musculoskeletal Diseases Center, University of Alabama, Birmingham Dr. James O'Dell, chief of the section of rheumatology and immunology, University of Nebraska, Omaha

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COPYRIGHT 2001 Gale Group