INTERFERON BETA-1B

INTERFERON BETA-1b
(in-ter-fer'on)
Betaseron
Classifications: immunomodulator; interferon; antineoplastic;
Therapeutic: immunomodulator; interferon
Prototype: Interferon alfa-2a
Pregnancy Category: C

Availability

0.3 mg vial

Action

Interferon beta-1b is a glycoprotein produced by recombinant DNA techniques using a strain of E. coli.

Therapeutic Effect

Both natural and recombinant DNA interferon beta-1b possess antiviral, antiproliferative, antitumor, and immunomodulatory activity. The effectiveness of interferon beta-1b for multiple sclerosis (MS) is based on the assumption that MS is an immunologically mediated illness.

Uses

Relapsing and relapsing-remitting multiple sclerosis.

Unlabeled Uses

AIDS, AIDS-related Kaposi's sarcoma, metastatic renal cell carcinoma, malignant melanoma, cutaneous T-cell lymphoma, acute hepatitis C.

Contraindications

Previous hypersensitivity to interferon beta-1b or human albumin, mannitol hypersensitivity; pregnancy (category C) but may cause a spontaneous abortion, lactation.

Cautious Use

Suicidal/mental disorders especially chronic depression; seizures; cardiac disease. Safety and efficacy in children <18 y are not established.

Route & Dosage

Multiple Sclerosis
Adult: SC 0.25 mg (8 million IU) q.o.d.

Administration

Subcutaneous

Reconstitute by adding 1.2 mL of the supplied diluent (0.54% NaCl) to vial and gently swirl. Do NOT shake. The resultant solution contains 0.25 mg (8 million units)/mL.
Discard reconstituted solution if it contains particulate matter or is discolored. Also discard unused solution.
Rotate injection sites; use 27-gauge needle to administer drug.
Store vials under refrigeration, 2°–8° C (36°–46° F) or at room temperature.

Adverse Effects (≥1%)

CNS: Headache, fever, fatigue, dizziness, lethargy, depression, somnolence, weakness, agitation, malaise, confusion or reduced ability to concentrate, anxiety, dementia, emotional lability, depersonalization, suicide attempts. CV: Tachycardia, peripheral edema, CHF (rare). GI: Nausea, vomiting, diarrhea. Hematologic: Leukopenia, thrombocytopenia, anemia. Metabolic: Hypocalcemia, elevated serum creatinine, elevated liver transaminases, autoimmune hepatitis, hepatic failure. Skin: Local skin necrosis at injection site, rash, pain at injection site. Body as a Whole: Alopecia, myalgias, flu-like syndrome.

Interactions

Drug: Zidovudine (AZT) levels are increased, resulting in toxicity.

Pharmacokinetics

Absorption: About 50% absorbed from SC sites. Distribution: Penetrates intact blood–brain barrier poorly; crosses placenta; distributed into breast milk. Metabolism: Rapidly inactivated in body fluids and tissue.

Nursing Implications

Assessment & Drug Effects

Monitor vital signs, neurologic status, and neuropsychiatric status frequently during therapy.
Lab tests: Monitor liver function at 1, 3, and 6 mo after initiation of therapy and as clinically warranted thereafter; monitor renal function, complete blood counts, and serum electrolytes periodically.
Assess for and promptly treat flu-like symptom complex (fever, chills, myalgia, etc.).
Assess injection sites; pain and redness are common reactions. Report tissue ulceration promptly.

Patient & Family Education

Learn and understand potential adverse drug reactions.
Learn proper technique for solution preparation and injection.
Self-medicate with acetaminophen (if not contraindicated) if flu-like symptom complex develops.
Avoid prolonged exposure to sunlight.
Use caution when performing hazardous activities until response to drug is known.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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