Chapter 107: Rheumatoid Arthritis

Update Summary

The following updates were made January 29, 2021:

• NOTIFICATION TO USERS OF THE PRINTED VERSION OF PHARMACOTHERAPY: There is an error in the print version of the 11th edition that has since been corrected in the online version. For users of the print version, the correct dose and frequency of oral methotrexate is 2.5 mg every 12 hours for 3 doses once weekly (Table 107-2).

KEY CONCEPTS

• The etiology of rheumatoid arthritis is unknown but is thought to result from a combination of genetic and environmental factors.

• Rheumatoid arthritis is a systemic autoimmune condition in which inappropriate activation of innate and adaptive immune responses cause inflammation leading to bone, cartilage, and synovium erosion.

• The primary goal of treatment includes targeting disease remission/low disease activity ultimately aiming at enhancing quality of life.

• Care should be provided by a rheumatology-trained clinician.

• Optimizing mental health and completing physical therapy are both crucial nonpharmacologic therapies in addition to providing comprehensive disease and treatment education.

• Drug treatment should be started as soon as a diagnosis is established.

• Choice of therapy depends on the level of disease activity, comorbid health conditions, patient preference, and often insurance coverage.

• Nonsteroidal anti-inflammatory drugs, analgesics, and corticosteroids are used as adjunctive therapy to disease-modifying antirheumatic drug therapy.

• Response to therapy is evaluated by patient subjective reports, physical examination, laboratory markers, and imaging.

Preclass Engaged Learning Activity

In 2009, the US Congress created an abbreviated pathway for approval and licensure of biologic products that are verified to have no clinically meaningful differences with a biologic product already approved by the US Food and Drug Administration (FDA). Agents approved through this abbreviated pathway are known as biosimilars. As the generic versions of small-molecule drugs, the goal in developing biosimilars is to increase the number of treatment options without increasing drug costs. Biosimilars provide formulary options to hospitals, health systems, and pharmacy benefit managers for use in patients with rheumatoid arthritis and other conditions treatable with biologic agents. Despite the availability of biosimilars for a variety of conditions, several challenges have limited use in clinical practice, including a lack of regulatory guidelines on switching from the original biologic product to the biosimilar. Clinicians are also uncertain about extrapolation of indications for biosimilars from the original biologic product. Post-marketing surveillance is needed to provide additional information regarding adverse reactions and any potentially meaninful differences between biologics and biosimilars to help guide incorporation into clinical practice.¹

Explore the FDA Website on biosimilars: https://www.fda.gov/Drugs/DevelopmentApprovalProcess/HowDrugsareDevelopedandApproved/ApprovalApplications/TherapeuticBiologicApplications/Biosimilars/default.htm.

Focus on the “Patient and Prescriber” video materials provided through the website. Through watching these presentations, the learner will become familiar with ...