DMARDs in the Management of Rheumatoid Arthritis

TRADITIONAL DMARDs

Overview

DMARDs are important in the prevention of joint deformities and injuries that can occur in RA. In general, block inflammation by interfering with the cellular signaling cascade (Benjamin, 2018). According to Smolen et al. (2014), therapy with DMARDs should be started as soon as diagnosis of RA is made. While there are several different types of DMARDs that can be utilized, Hydroxychloroquine (HCQ) and Methotrexate (MTX) a few of the most commonly used drugs (Singh et al., 2012).

Pharmacokinetics

DMARDs can be administered orally or intravenously (Benjamin, 2018). They can be administered alone or in combination with other drugs (Kumar, 2013).

HCQ is usually the DMARD of choice in the initial stages of treatment. In the body, HCQ increases the pH in cells, which alters protein degradation resulting in down-regulation of the immune system. Typical doses for adult patients range from 300 mg/day to 400 mg/day. HCQ is then partially metabolized by the liver. (Kumar, 2013).

MTX is an immunomodulatory compound. It interferes with DNA synthesis via various mechanisms such as reducing neutrophil adhesion and pyrimidine supply in dividing cells. In addition, MTX inhibits gene expression and cell-mediated immunity in the body (Benjamin, 2018). The dosing ranges from 7.5 mg/week to 25 mg/week as the patient progresses through the treatment regimen (Kumar, 2013). It is then metabolized and excreted by the kidneys (Kumar, 2013).

Clinical Implications

Common adverse effects of all DMARDs include headache, nausea, and vomiting. More specifically, HCQ can induce visual disturbances, abdominal cramps, and peripheral neuritis. MTX can cause arachnoiditis, stomatitis, and nephropathy. Traditional DMARDs also pose an increased risk of cardiovascular issues and bDMARDs should be used in patients with a preexisting cardiovascular condition (Solomon et al., 2013).

The PT should be aware of seizures, skin irritations, gastrointestinal (GI) symptoms, and blood pressure issues when treating a patient receiving DMARDs as these symptoms can negatively affect the treatment session. In addition, assessing pulmonary function and back pain is of utmost importance as they can be indications that the patient may be in danger of drug toxicity. If the patient presents with any abnormalities in vitals or metabolic outcome measures these adverse signs and symptoms should be appropriately noted and relayed to the primary physician (Ciccone, 2013).