Biologic DMARDs: TNF Inhibitors & Action

• Biologic DMARDs (bDMARDs) are a class of disease-modifying antirheumatic drugs.
• Etanercept is the prototype medication for biologic DMARDs and is a tumor necrosis factor (TNF) inhibitor.

Medication Classification

• Biologic DMARDs are classified as antirheumatic medications.
• Other TNF inhibitors include infliximab, adalimumab, golimumab, and certolizumab pegol.
• Abatacept is a T cell costimulatory inhibitor.
• Tocilizumab and sarilumab are IL-6 receptor inhibitors.
• Rituximab is an anti-CD20 antibody.

Pharmacologic Action

• bDMARDs inactivate tumor necrosis factor (TNF).
• The inactivation of TNF reduces inflammation and causes immunosuppression
• These medications are tumor necrosis factor antagonists.
• TNF antagonists bind with naturally occurring tumor necrosis factor.
• The binding of TNF antagonists prevents the naturally occuring TNF from attaching to cells on the surface of synovial tissue in the joints.
• This prevents stimulation of of an inflammatory reaction in the joints of clients who have RA.
• Biologic DMARDs can be given with methotrexate, a nonbiologic DMARD, for an enhanced effect.

Adverse Drug Reactions

• Biologic DMARDs increase susceptibility to infections because tumor necrosis factor helps fight infections, so when it is suppressed, a client’s susceptibility to infections increases.
• Possible adverse effects include dizziness, pharyngitis, upper respiratory infections, and abdominal pain.
• Other possible adverse effects include psoriasis, and pancytopenia, which is an abnormally low level of platelets, RBCs, and WBCs.
• Heart failure can reoccur in clients with a previous history, as well as in clients who have no experience with heart failure.
• Reactivation of latent tuberculosis, or TB, can occur, as well as new development of TB.
• Certolizumab is considered the only biologic DMARD that is considered safe to use during pregnancy because it does not cross the placenta.

Interventions

• Monitor for manifestations of infection (redness, warmth, itching) due to increased susceptibility to infections.
• Reaction at the injection site occurs in 37% of clients receiving etanercept. Assess for manifestations of infection prior to each injection and monitor for reactions during therapy.
• Monitor for manifestations of heart failure (cough, shortness of breath, elevated blood pressure and heart rate, pink sputum).
• Monitor CBC for manifestations of myelosuppression.
• Monitor liver enzymes for indications of liver dysfunction.
• Test clients for tuberculosis both prior to therapy with a nonbiologic DMARD and periodically throughout therapy.

Administration

• Give etanercept by subcutaneous injection once weekly.
• Monitor the injection site for redness, pain, and swelling after administration.

Client Instructions

• Report manifestations of infection immediately.
• Report any type of skin rash.
• Report an injection site reaction that does not subside in a few days.
• Clients are at risk for acquiring or transmitting infections if immunized with a live virus vaccine.
• Clients should be up to date on all vaccines prior to starting etanercept.

Contraindications and Precautions

• Contraindicated for clients who have an active infection, a hematologic disease, or a malignancy.
• Not appropriate for clients who have autoimmune demyelinating disorders of the central nervous system, such as multiple sclerosis.

Interactions

• Concurrent administration with chemotherapeutic medications such as methotrexate may cause bone marrow suppression, which results in a decrease in platelets as well as red and white blood cells.
• Do not give etanercept with anakinra due to the increased risk of infections.
• Avoid the use of live vaccines.

Question 1

A primary care provider prescribes etanercept to treat a client’s rheumatoid arthritis. Prior to beginning the treatment, the client requires testing for which of the following?

• The correct answer is c) Tuberculosis.
• Prior to biologic DMARD therapy, clients need to be tested for tuberculosis due to the risk of reactivation of latent TB or development of new TB.

Question 2

A nurse is caring for a client taking etanercept. Which of the following adverse effects is most important to mention when educating this client?

• The correct answer is a) Injection site reaction can occur.
• Injection site reactions are common (37% of clients receiving etanercept).