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Pharmacy Practice in Focus: Health Systems
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A guide to treatment of rheumatoid arthritis, the most common chronic inflammatory joint disease.
Rheumatoid arthritis (RA) is the most common chronic inflammatory joint disease, affecting an estimated 0.5% to 1% of the population in Northern Europe and North America. This prevalence may be lower in other, more rural parts of the world.1,2 There is no clear cause of RA; however, genetic and environmental factors, such as smoking, obesity, and infection, may contribute to the development, persistence, and outcomes of RA.2
Approach to Therapy
The majority of patients with a confirmed diagnosis of RA will require non-biologic disease-modifying antirheumatic drugs (DMARDs) in addition to glucocorticoids, non-steroidal anti-inflammatory drugs (NSAIDs), analgesics, and other non-pharmacologic treatments such as physical and occupational therapy. Furthermore, the rate of biologic DMARD use is rapidly rising and there are new biologic agents targeting a variety of inflammatory mediators emerging regularly.
The American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) have published guidelines for the use of these agents in RA with an emphasis on early DMARD institution and a stepwise approach to therapy.3-5 Figure 1 summarizes this basic treatment strategy which is based on 4 main considerations:
Typically, non-biologic DMARDs are first-line therapy following RA diagnosis, with methotrexate being the preferred oral agent.5 If clinical response is not sufficient following an adequate trial of at least 3 months, then another DMARD, such as hydroxychloroquine (HCQ) or leflunomide (LEF), is added to current therapy. If the patient cannot tolerate their current drug therapy then a switch is made. In more severe cases of RA, or in the presence of poor prognostic features, including high tender and swollen joint counts, evidence of radiographic erosions, elevated levels of rheumatoid factor (RF), and/or anti-cyclic citrullinated peptide (anti-CCP) antibodies, adding or switching to a biologic DMARD is considered.3-5
The majority of clinical evidence supports the use of anti—tumor necrosis factor (TNF) agents (eg, etanercept, infliximab, adalimumab); however, other, newer agents targeting different inflammatory mediators, such as IL-1 and IL-6, are gaining popularity. The clinical studies of these biologic agents are largely 2-arm studies of the biologic DMARD plus methotrexate versus methotrexate monotherapy. As a result, the evidence to support choosing one biologic DMARD over another is based on indirect comparisons across trials.6 In fact, results from the first head-to-head study of biologic DMARDs, the AMPLE study, were just published in January 2013. This study randomized biologic DMARD-naïve patients with moderate to severe RA currently on stable methotrexate doses to either subcutaneous abatacept or adalimumab arms. Results demonstrated equal clinical efficacy and inhibition of radiographic progression with similar rates of adverse events after 1 year.7 Additional head-to-head studies are needed to support clinical decision making in deciding which biologic agent to start. At this point, clinical efficacy is considered equivalent across these agents and achieving low disease activity or remission is often the result of trial and error.
As a health-system pharmacist, you may encounter these agents in multiple settings. Patients having a severe flare may be admitted for intravenous (IV) infusion or may be getting routine maintenance infusions at your hospital. Patients coming to your clinic may be newly started on a subcutaneous formulation and have questions regarding cost, adverse effects, monitoring, and administration. Table 18-17 provides an overview of the biologic agents with FDA-approved indications for RA.
Prior to Therapy Evaluation
As the pharmacist, there are numerous opportunities to be involved in the decision to start DMARD therapy and the monitoring that is necessary prior to and during therapy. All patients being considered for DMARD therapy require a baseline complete blood count, liver transaminases, and serum creatinine. Beyond 3 months of therapy, routine lab monitoring is recommended every 8 to 12 weeks. Tuberculosis screening is recommended for patients being considered for a biologic DMARD. This involves a tuberculin skin test for all patients and a skin test plus chest radiograph for patients with risk factors for latent tuberculosis (TB) infection.
This recommendation is based on evidence of higher incidence of TB following anti-TNF-α therapy. Additionally, the ACR guidelines support compliance with Centers for Disease Control and Prevention recommendations for periodic pneumococcal and annual influenza vaccinations for all patients as well as completion of the hepatitis B vaccination series for high-risk patients.3,4 Table 2 provides other general recommendations for baseline evaluation and vaccination in patients receiving biologic and non-biologic DMARDs.3,4
Patient Counseling
Education is crucial for RA patients newly starting on a DMARD, particularly a biologic agent. Listed below are a few key counseling points that should be addressed before starting one of these drugs.
Suzanne J. Francart, PharmD, BCPS, CPP, is a clinical pharmacist in the University of North Carolina Medical Center Rheumatology Clinic, Chapel Hill, North Carolina.
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