Non-biologic disease-modifying antirheumatic drug (DMARD) therapy: Nursing pharmacology

Nonbiologic disease modifying antirheumatic drugs, or DMARDs for short, are a group of medications primarily used to treat rheumatoid arthritis. The most commonly used ones are methotrexate, sulfasalazine, leflunomide, and hydroxychloroquine. Now, in addition to rheumatoid arthritis, most of these medications have other indications. So, methotrexate can be used to treat psoriasis and certain cancers. Sulfasalazine is also indicated for ulcerative colitis. Finally, hydroxychloroquine can be also used to treat malaria and systemic lupus erythematosus.

Now, nonbiologic DMARDs can be administered orally, subcutaneously, intramuscularly, and intravenously. Once administered, they mainly work by inhibiting the immune response and suppressing inflammation.

However, nonbiologic DMARDs can cause some notable side effects, such as bone marrow suppression, which can lead to conditions like anemia and leukopenia; as well as severe skin reactions and stomatitis, or painful mouth sores. Other general side effects include gastrointestinal disturbances, such as anorexia, nausea, vomiting, and diarrhea. In addition, the immunosuppressive effects of these medications can lead to an increased risk of developing infections and certain cancers.

More specifically, methotrexate can also lead to pulmonary fibrosis, hepatotoxicity, and nephrotoxicity.
Next, sulfasalazine can result in hypersensitivity reactions like anaphylaxis and orange discoloration of the urine; while important side effects of leflunomide include heart palpitations, hepatoxicity, and interstitial lung disease.

Finally, hydroxychloroquine’s most common side effects are vision problems due to corneal or retinal damage. In addition, some clients may also experience neurological side effects, such as seizures, as well as cardiovascular side effects like heart failure, QT prolongation, and torsade de pointes.

As far as contraindications go, these medications should not be used during pregnancy.

Methotrexate has some important boxed warnings, including its toxic effects on liver, kidneys, and lungs. On top of that, methotrexate should not be combined with NSAIDs or proton pump inhibitors, since these medications can decrease the clearance of methotrexate from the body, potentially leading to elevated levels of methotrexate. Lastly, methotrexate can decrease the effects of digoxin and folic acid.

Now, sulfasalazine is contraindicated for use in clients with hypersensitivity to sulfonamides or salicylates. It also decreases the absorption of both folic acid and iron; and it can increase the hypoglycemic effect of oral hypoglycemics and increase the anticoagulant effect of oral anticoagulants.

On the other hand, leflunomide has a boxed warning due to its hepatotoxic effects, and it can increase the anticoagulant effects of warfarin.

Hydroxychloroquine is contraindicated in clients with conditions that affect their visual field, such as macular degeneration. And it can increase digoxin levels, potentially leading to digoxin toxicity.

Finally, keep in mind that because of the depressive effects of DMARDs on the immune system, these medications can decrease the effectiveness of inactivated vaccines; while administration of live, attenuated vaccines may result in illness due to uninhibited growth of the live attenuated virus.

Now, when your client with rheumatoid arthritis is prescribed a nonbiologic DMARD agent like methotrexate, first perform a focused baseline musculoskeletal assessment, checking for joint pain, stiffness, swelling, and range of motion. Then, review their most recent laboratory test results, including renal and hepatic function, CBC, rheumatoid factor, CRP and ESR; and be sure to confirm a negative pregnancy test for clients of childbearing age. Lastly, review diagnostic test results, including X-rays and ultrasound.

Next, explain to your client how their medication will help to decrease their joint pain and inflammation as well as increase their day-to-day functionality.