Leflunomide (Arava - Hoechst Marion Roussel), which inhibits pyrimidine synthesis, and etanercept (Enbrel - Immunex/Wyeth-Ayerst), which blocks the action of tumor necrosis factor (TNF), have been approved by the FDA for treatment of rheumatoid arthritis. A third drug, infliximab (Remicade - Centocor), which also blocks TNF and has been used to treat rheumatoid arthritis, was approved earlier for treatment of Crohn's disease. Its use in Crohn's disease will be reviewed in a future issue.

View the Flowchart: Rheumatoid Arthritis Treatment

View the Inhibitors and Inducers of CYP Enzymes, P-Glycoprotein, and Other Transporters tables

Rheumatoid arthritis (RA) is prevalent in 0.5% of adults in the US; it is about 2.5 times more common in women than in men. Guidelines for treatment of RA from the American College of Rheumatology were recently updated. The goal of treatment is to minimize disease activity and prevent irreversible joint damage.

Psoriatic arthritis is a chronic inflammatory arthropathy associated with psoriasis. A recent review found that about 20% of patients with psoriasis have psoriatic arthritis. Updated guidelines for treatment of psoriatic arthritis have recently been published.

View Expanded Table: Some Conventional DMARDs for Rheumatoid Arthritis

The FDA has approved tofacitinib (toe” fa sye’ ti nib; Xeljanz – Pfizer), an oral Janus kinase (JAK) inhibitor, for treatment of adults with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response to or are intolerant of methotrexate. Ruxolitinib (Jakafi) is the only other JAK inhibitor available in the US; it is FDA-approved for treatment of myelofibrosis.

In recent years, several new drugs have been approved by the FDA for use in multiple sclerosis (MS), and many others are in the pipeline. Most recently, teriflunomide (Aubagio – Genzyme) became the second oral drug to be approved by the FDA for treatment of relapsing forms of MS.

The FDA has approved upadacitinib (Rinvoq – Abbvie), an oral Janus kinase (JAK) inhibitor, for treatment of adults with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response to or cannot tolerate methotrexate (Trexall, and others). Upadacitinib is the third JAK inhibitor to be approved in the US for treatment of RA; tofacitinib (Xeljanz, Xeljanz XR) and baricitinib (Olumiant) were approved earlier.