DMARDs in the Management of Rheumatoid Arthritis

TRADITIONAL DMARDs

Overview

DMARDs are crucial in preventing joint deformities and injuries that can occur as a result of rheumatoid arthritis (RA). In essence, they interfere with the cellular signaling cascade that promotes inflammation[1]. A patient diagnosed with RA will achieve the best possible prognosis by starting DMARD therapy as soon as the diagnosis is made[2]. While there are several different types of DMARDs that can be utilized, Hydroxychloroquine (HCQ) and Methotrexate (MTX) are a few of the most commonly used drugs[3].

Pharmacokinetics

DMARDs can be administered orally or intravenously[1]. They can be administered alone or in conjunction with other drugs[4].

HCQ is most often the DMARD of choice in the initial stages of treatment. In the body, HCQ increases the pH in cells, which alters protein degradation and thus results 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[4].

MTX is an immunomodulatory compound. It interferes with DNA synthesis by reducing neutrophil adhesion and pyrimidine supply in dividing cells. In addition, MTX inhibits gene expression and cell-mediated immunity in the body[1]. The dosing ranges from 7.5 mg/week to 25 mg/week as the patient progresses through the treatment regimen. It is then metabolized and excreted by the kidneys[4].

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 instead for patients with a preexisting cardiovascular condition[5].

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 life-threatening adverse effects, the patient should cease taking the medication and seek medical help[1].

References

  1. 1.0 1.1 1.2 1.3 Benjamin O. Disease Modifying Anti-Rheumatic Drugs (DMARD). Current neurology and neuroscience reports. https://www.ncbi.nlm.nih.gov/books/NBK507863/. Published October 27, 2018.
  2. Smolen JS, Landewé R, Breedveld FC, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2013 update. Annals of the Rheumatic Diseases. https://ard.bmj.com/content/73/3/492. Published March 1, 2014.
  3. Singh JA, Furst DE, Bharat A, et al. 2012 update of the 2008 American College of Rheumatology recommendations for the use of disease-modifying antirheumatic drugs and biologic agents in the treatment of rheumatoid arthritis. Current neurology and neuroscience reports. https://www.ncbi.nlm.nih.gov/pubmed/22473917. Published May 2012
  4. 4.0 4.1 4.2 Kumar P, Banik S. Pharmacotherapy Options in Rheumatoid Arthritis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3747998/. Published August 8, 2013.
  5. Solomon DH, Curtis JR, Saag KG, et al. Cardiovascular risk in rheumatoid arthritis: comparing TNF-α blockade with nonbiologic DMARDs. Current neurology and neuroscience reports. https://www.ncbi.nlm.nih.gov/pubmed/23885678. Published August 2013.
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