INTERFERON GAMMA-1B

Medical Diagnosis and Drugs, Medications

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

Availability

100 mcg (2 million IU)/0.5 mL vial

Action

Antiviral: Has potent phagocyte-activating effects that include stimulating macrophages and generation of toxic oxygen metabolites (i.e., free radicals) capable of destroying virally infected cells. Antineoplastic: It also exerts antitumor effects by increasing expression of tumor suppressor genes and activating macrophages to lyse tumor cells. Immunomodulatory: Interferon gamma is produced by T-cells and natural killer (NK) cells after activation with immune or inflammatory stimuli. Interferon gamma stimulates macrophages to increase IL-12 and TNF-alpha production, which enhances interferon gamma synthesis. Interleukin-10 downregulates interferon gamma production by NK and T-cells by preventing macrophage secretion of IL-12 and TNF-alpha.

Therapeutic Effect

Is a naturally occurring cytokine with antiviral, immunomodulatory, and antiproliferative activity. It enhances phagocyte function in chronic granulomatous disease and improves killing of viruses; also enhances osteoclast function in malignant osteopetrosis.

Uses

Chronic granulomatous disease, severe malignant osteopetrosis.

Unlabeled Uses

Idiopathic pulmonary fibrosis, refractory mycobacterium infection, ovarian cancer.

Contraindications

Hypersensitivity to interferon gamma or products derived from E. coli; pregnancy (category C); lactation.

Cautious Use

Preexisting cardiac disease, CHF, cardiac arrhythmias; seizure disorders and compromised CNS function; myelosuppression. Safety and efficacy in infants <1 y are not established.

Route & Dosage

Chronic Granulomatous Disease, Osteopetrosis
Adult/Child: SC BSA ≥0.5 m², 50 mcg/m² 3 times weekly
Adult/Child: SC BSA ≤0.5 m², 1.5 mcg/kg 3 times weekly

Idiopathic Pulmonary Fibrosis
Adult: SC 180–200 mcg 3 times weekly

Administration

Note: Pretreatment (4 h before) with acetaminophen is recommended to reduce headache, myalgia, and fever. Treatment should be continued 24 h postinjection.

Subcutaneous

Do not shake vial. Inject SC undiluted into right or left deltoid area or anterior thigh area.
Avoid intradermal or IV injection. Rotate injection sites.
Store 2°–8° C (36°–46° F); do not freeze. Discard any unused portions or any vial left at room temperature for >12 h.

Adverse Effects (≥1%)

Body as a Whole: Fever, fatigue, chills, myalgia, arthralgia, night sweats. CNS: Headache, altered mental status, ataxia, confusion, dizziness, Parkinsonian symptoms, disorientation, seizures, hallucinations. CV: Heart block, heart failure, DVT, hypotension, MI, syncope, tachyarrhythmia. GI: Nausea, vomiting, diarrhea. Hematologic: Leukopenia, thrombocytopenia. Respiratory: Bronchospasm, interstitial pneumonitis, pulmonary embolism, tachypnea. Skin: Local skin necrosis at injection site, pain at injection site, rash. Urogenital: Reversible renal insufficiency.

Interactions

Drug: Use cautiously with amiophylline, fosphenytoin, phenytoin, theophylline, warfarin.

Pharmacokinetics

Absorption: 90% absorbed from SC site. Peak: 7 h. Half-Life: 5.9 h.

Nursing Implications

Assessment & Drug Effects

Monitor CV status frequently. Report promptly severe hypotension and/or syncope.
Monitor for and report S&S of infection.
Lab tests: Baseline and at 3 mo CBC with differential and platelet counts; complete blood chemistry (including renal and liver function tests), and urinalysis.

Patient & Family Education

Report promptly: skin rash, itching, unusual weakness or tiredness, chest pain or palpitations, or signs of an infection.
Do not accept vaccination with a live vaccine during or for 3 mo following the end of therapy.

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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