Interferon Beta-1a

A to Z Drug Facts

 Action Has antiviral, antiproliferative, and immunoregulatory activities. Binds to specific cell membrane receptors that induce the expression of a number of gene products that mediate the biological actions of interferon beta-1a.

 Indications Treatment of relapsing forms of multiple sclerosis to slow accumulation of physical disability and decrease the frequency of clinical exacerbations.

 Contraindications Hypersensitivity to natural or recombinant interferon beta, human albumin, or any other component of the formulation.

 Route/Dosage

Adults: Avonex: IM 30 mcg once weekly. Rebif: SC 44 mcg 3 times/wk.

 Interactions

Live Virus Vaccines (eg, Measles, Mumps, Polio, Rubella): May inhibit antibody response after immunization; avoid concurrent use.

 Lab Test Interferences None well documented.

 Adverse Reactions

CARDIOVASCULAR: Syncope; vasodilation. CNS: Headache; asthenia; malaise; depression; sleep difficulty; dizziness; muscle spasm; speech disorder; seizures; ataxia. DERMATOLOGIC: Urticaria; alopecia; nevus; herpes zoster; herpes simplex. EENT: Sinusitis; otitis media; decreased hearing. GI: Nausea; diarrhea; dyspepsia; abdominal pain; anorexia. GU: Vaginitis; ovarian cyst. HEMATOLOGIC: Anemia; eosinophilia. METABOLIC: Increased AST. RESPIRATORY: Upper respiratory tract infection; dyspnea. OTHER: Injection site reactions (eg, bruising, necrosis, inflammation, pain); flu-like symptoms (eg, fever, chills, myalgia); pain; chest or joint pain; hypersensitivity reactions; photosensitivity.

 Precautions

Pregnancy: Category C. Lactation: Undetermined. Children: Safety and efficacy in children less than 18 yr not established. Suicide/Depression: Suicide attempts occurred in clinical trials. Report depression and suicidal ideation immediately. Seizures: Use caution when administering to patients with preexisting seizure disorder. Cardiac Disease: Interferon beta-1a-induced flu syndrome may prove stressful to patients with severe cardiac conditions (eg, CHF, arrhythmia, angina). Photosensitivity: May occur. Caution patient to use sunscreen (SPF 30 or more) and wear protective clothing until tolerance is determined.

 Administration/Storage

• Allow vial of interferon beta-1a and diluent to warm to room temperature before preparation.
• Reconstitute with supplied diluent.
• Swirl gently to dissolve; do not shake solution.
• Discard solution if it contains particulate matter or is discolored other than slightly yellow.
• Inject IM.
• Rotate injection sites.
• Store drug in refrigerator before reconstitution. If refrigeration is unavailable, store at room temperature (less than 77°F) for up to 30 days.
• After reconstitution, refrigerate for 6 hr or less.
• Use product within 6 hr of reconstitution. Discard unused solution.
• Do not freeze or expose to high temperatures.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Obtain baseline CBC with differential, platelets, LFTs, and electrolytes. Monitor throughout therapy.
• Assess patient for GI, CNS, cardiovascular, respiratory, dermatological, and hematological reactions. If present, notify health care provider.
• Monitor hydration if patient experiences anorexia, nausea, or diarrhea.
• Monitor results of laboratory tests.
• Monitor I&O strictly. Increase fluid intake if patient becomes dehydrated. Weigh patient daily.
• Assess patient for depression and suicide potential.
• If patient experiences adverse CNS symptoms (eg, loss of consciousness, mental status change, dizziness, confusion), take safety precautions such as lowering bed, putting side rails up, and supervising ambulation.
• Implement infection control measures if WBC drops; implement bleeding precautions if platelet count drops.
• Discuss need for antiemetic with health care provider if nausea or vomiting develops.
• If flu-like symptoms occur, administer drug in evening and administer acetaminophen as prescribed for fever and headache.

 Patient/Family Education

• Stress importance of returning for follow-up blood tests.
• Teach patient infection control measures, bleeding precautions, and energy conservation measures.
• Caution patient to use safety precautions and not to perform activities that require mental alertness if decreased mental status or dizziness occurs.
• Advise patient to take medication at bedtime if flu-like symptoms occur, and to use acetaminophen as needed.
• Explain importance of adequate hydration.
• Teach patient or family how to store, reconstitute, and administer drug IM.
• Encourage patient to report depression or suicidal ideation immediately.
• Provide puncture-resistant container for disposal of used syringes and needles.
• Instruct patient to report the following symptoms that may represent side effects: swollen ankles, dyspnea, chest pain, noisy breathing.
• Instruct patient to report the following symptoms to health care provider: flu-like symptoms, injection site pain, headache, fever, convulsions.
• Instruct patient to notify health care provider immediately if depression occurs.

Books@Ovid
Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts