Enbrel (Etanercept)

What is Enbrel?

• Enbrel or etanercept is a Tumor Necrosis Factor (TNF) alpha Inhibitor
• TNF-alpha is produced by Macrophages and T cells
• TNF-alpha is involved in release of Cytokines and Chemokines, Leukocyte recruitment, and Granuloma formation
• TNF-alpha Inhibition results in reduction of inflammation
• Enbrel Half-life is 5 days

Benefits of Enbrel:

• Diminution of Inflammation
• Reduction of Pain and Swelling
• Minimizing Joint Damage
• Avoiding Disability
• Preventing Muscle Weakness and De-conditioning
• Improving the overall feeling of Well-being
• Resumption of Normal Daily Function

Potential side effects

• Infection. Patient Selection, PPD testing, brining up-to-date Vaccinations before starting Biologics, Early Antibiotic therapy, and Holding Enbrel in case of infection should help minimize this risk.
• Neutropenia. This requires periodic CBC with Diff for monitoring. Neutropenia usually improves with holding the Enbrel or taking it less frequently. In cases where it would take a long time for neutropenia to resolve (over 6-8 weeks), I would avoid Enbrel in those patients.
• Cancer. There is mixed evidence as to the risk of cancer with use of biologics including Enbrel. This is because of the increase risk of cancer with the disease itself, use of other DMARDs along with Enbrel, and lack of long term data. Proper patient selection, considering individual risks and benefits, and increased surveillance with cancer screening should help minimize this risk.
• Multiple Sclerosis (MS). There are few case reports of MS more commonly with Enbrel than the other biologics. Enbrel should not be used in anyone with history of Guillain-Barré syndrome, Multiple Sclerosis, Optic Neuritis, Transverse Myelitis. If in doubt, consult a neurologist.
• Lupus Like Reaction, Interstitial Lung Disease, and Vasculitis. These are rare events and they usually present with new onset of lupus like symptoms, skin eruptions, and shortness of breath respectively.
• Local Skin Reaction. These are common but localized to the size of a quarter and usually resolves over time. Enbrel should be stopped if the reaction is larger or more wide-spread.

Enbrel is approved for:

• Ankylosing Spondylitis
• Juvenile Idiopathic Arthritis
• Psoriatic Arthritis
• Rheumatoid Arthritis
• Available in 50 mg once-a-week or 25 mg twice weekly Subcutaneously

Before Starting Enbrel

• Bring up-to-date Vaccinations
• PPD, or QuantiFERON TB Gold, or T-SPOT. TB test to screen for latent tuberculosis
• Recent CBC with Diff, ESR, CRP, Ferritin for baseline exam
• Hepatitis C Serology
• Hepatitis B Surface Antigen
• Look for open wound, infection, heart failure, or Melanoma

After Starting Enbrel

• Avoid Live Vaccine
• PPD, or QuantiFERON TB Gold, or T-SPOT. TB test to screen for latent tuberculosis annually
• Periodic CBC with Diff to look for Neutropenia
• Hold in case of infection, Surgery, Colonoscopy?, and Major dental Procdure?
• Monitor for Heart Failure and Neurologic Symptoms
• Cancer Screening
• Pregnancy Category B Medication
• Consider Extending Enbrel intervals with improvement