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Conscientious Use of Rofecoxib (Vioxx) 50mg
Thomas H. Lee, MD, PCHI Chief Medical Officer
Tara Abrams, PharmD, PCHI Pharmacy Programs Team Leader
Volume XIII, Issue 3

In the spring of 2002, Merck & Co., Inc. revised the Vioxx package insert to make clear that this drug is not recommended for use at 50 mg per day for more than five days.  This change reflects the results of the Vioxx Gastrointestinal Outcomes Research (VIGOR) Study.  VIGOR was a study with 8076 patients (mean age 58; Vioxx n=4047, naproxen n=4029) and a median duration of exposure of 9 months.  The VIGOR and other studies have demonstrated significant side effects associated with Vioxx.  Below is a brief summary of the safety concerns to consider when prescribing Vioxx.

·        Patients with a medical history of ischemic heart disease: The VIGOR Study found the risk of developing a serious cardiovascular thrombotic event was significantly higher for patients treated with Vioxx 50mg QD (n=45) as compared to patients treated with naproxen 500mg BID (n=19).  The significance of this occurrence will remain unknown until prospective studies specifically designed to look at CVD are performed.  Of note, aspirin use was not permitted in this trial.

·        Vioxx is not a substitute for aspirin for cardiovascular prophylaxis.  Therefore, in patients taking Vioxx, antiplatelet therapies should not be discontinued for patients with an indication for cardiovascular prophylaxis.  However, the combination of aspirin with COX-2 medications essentially negates the GI protective effects of the COX-2’s.

·        Vioxx should be used with caution, and introduced at the lowest dose for patients with fluid retention, hypertension, or heart failure.  This adverse effect may be dose-related. Clinical trials for rheumatoid arthritis have shown the incidence of hypertension to be twice as high in patients taking Vioxx 25mg QD, compared with patients treated with naproxen 1000mg QD.

Recommendations:

·        Since COX 2’s have not been demonstrated to be more effective than older and non-specific NSAIDS, their use in patients without risk factors for GI bleeding or treatment of acute musculoskeletal pain should be discouraged.

·        COX 2’s are reasonable choices for patients with rheumatoid arthritis or osteoarthritis. who are at high risk of GI bleeding based on their ARAMIS score.

·        For those patients with concomitant CVD risk factors in whom low-dose aspirin prophylaxis is indicated, the risk of GI bleeding should be considered (since aspirin along with a COX-2 essentially negates most of the benefits of the COX-2).

  Vioxx Dosage and Administration for Arthritis:
Note: the FDA has not established 50mg as a safe and effective dose for arthritis.

Osteoarthritis:The recommended starting dose is 12.5mg QD. The dosage can be increased to 25mg QD. The maximum daily dose is 25mg QD.

Rheumatoid Arthritis:The recommended dose is 25mg QD. The maximum daily dose is 25mg QD.