interferon gamma-1b

interferon gamma-1b,

a synthetic form of interferon-beta produced by recombinant technology that acts as a biologic response modifier and antineoplastic. It is used to reduce the frequency and severity of serious infections associated with chronic granulomatous disease; it is administered subcutaneously.

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interferon (in´trfir´on),

n a small class of glycoproteins capable of exerting antiviral activity in homologous cells through metabolic processes involving synthesis of RNA.

interferon alpha,

n a type formed by leukocytes in response to viral infection or by stimulation with double-stranded RNA. These protein products are used as antineoplastic agents. Specifically used as an antineoplastic agent for the treatment of Kaposi's sarcoma in AIDS patients. See also interferon alfa-2a.

interferon alfa-2a/interferon alfa-2b/interferon alfa-n1/interferon alfa-n3,

n brand names: Roferon-A, Intron-A, Alferon N;
drug class: biologic response modifier;
action: antiviral action inhibits viral replication by reprogramming virus; antitumor action suppresses cell proliferation; immunomodulating action phagacytizes target cells;
uses: hairy-cell leukemia in persons older than 18 years, metastatic melanoma, AIDS, Kaposi's sarcoma, bladder carcinoma, lymphomas, malignant myeloma, mycosis fungoides.

interferon beta,

n a type formed by fibroblasts by stimulation similar to the alpha form.

interferon gamma,

n a type formed by lymphocytes in response to mitogenic stimulation. See also interferon gamma-1b.

interferon gamma-1b,

n brand name: Actimmune;
drug class: biologic response modifier;
action: species-specific protein synthesized in response to viruses, enhances antibody-dependent cellular cytotoxicity, enhances natural killer cell activity;
uses: serious infections associated with chronic granulomatous disease.

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interferon gamma-1b

Actimmune

Pharmacologic class: Biological response modifier

Therapeutic class: Antineoplastic

Pregnancy risk category C

Action

Enhances cellular toxicity and killer cell activity and promotes generation of oxygen metabolites in phagocytes, resulting in destruction of microorganisms.

Availability

Injection: 100 mcg (2 million international units)/0.5-ml vial

⊘Indications and dosages

➣ Chronic granulomatous disease; severe malignant osteopetrosis

Adults with body surface area (BSA) above 0.5 m²: 50 mcg/m² (1 million international units/m²) subcutaneously three times weekly

Adults with BSA of 0.5 m² or less: 1.5 mcg/kg subcutaneously three times weekly in deltoid or anterior thigh

Contraindications

• Hypersensitivity to drug, its components, or Escherichia coli-derived products

Precautions

Use cautiously in:
• thyroid disorders, bone marrow depression, hepatic or cardiac disease, seizure disorders, compromised CNS function
• pregnant or breastfeeding patients
• children ages 18 and younger.

Administration

• Administer into deltoid muscle by subcutaneous route only.
• Give at bedtime if flulike symptoms occur.
• Provide antiemetics to ease nausea and vomiting, as prescribed.

Route	Onset	Peak	Duration
Subcut.	Unknown	7 hr	Unknown

Adverse reactions

CNS: dizziness, confusion, paresthesia, lethargy, depression, difficulty thinking or concentrating, insomnia, anxiety, fatigue, amnesia, nervousness, drowsiness, asthenia, malaise

CV: chest pain, hypertension, palpitations, arrhythmias

GI: nausea, vomiting, diarrhea, constipation, abdominal pain, pancreatitis

GU: proteinuria

Hematologic: anemia, leukopenia, thrombocytopenia, neutropenia

Musculoskeletal: joint pain, back pain, myalgia

Skin: flushing, rash, dry skin, erythema

Other: flulike symptoms, weight loss, edema, hypersensitivity reaction

Interactions

Drug-drug. Bone marrow depressants: increased bone marrow depression

Zidovudine: increased zidovudine blood level

Drug-diagnostic tests. Hepatic enzymes: increased levels

Neutrophils, platelets: decreased counts

Patient monitoring

☞ Before and monthly during therapy, assess CBC with white cell differential, glucose and electrolyte levels, and liver and kidney function tests.
• Assess fluid intake and output. Keep patient well hydrated.
• Monitor for GI upset. Provide small, frequent meals or antiemetics to ease severe nausea and vomiting.
☞ Monitor patient for mental status changes and depression.
• Assess for flulike symptoms. If these occur, give drug at bedtime and provide supportive care, such as rest and acetaminophen for headache and fever.

Patient teaching

• Teach patient or caregiver how to administer drug subcutaneously, rotate injection sites, and track dosing schedule and injection sites on calendar.
☞ Tell patient to contact prescriber immediately if depression occurs.
• Advise patient to eat small, frequent meals to combat nausea, vomiting, and appetite loss.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Inform female patient that drug is linked to fetal abnormalities. Advise her not to get pregnant during therapy, and to use barrier contraception.
• Tell female patient to consult prescriber before breastfeeding.
• Tell patient he'll need regular follow-up examinations and blood tests to monitor drug effects.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.