Interferon Alfa-2A information from DrugsUpdate  

Pharmacodynamics

Pharmacokinetics

Interferon alfa-2a has antiviral, antitumour and immunomodulatory activity. It inhibits replication of a wide range of RNA and DNA viruses. It also exerts antiproliferative effects on normal and malignant cells. Interferon alfa-2a suppresses antibody formation through an effect on B-lymphocytes and inhibits onset of delayed hypersensitivity.

Absorption
>80% is absorbed (IM); peak plasma concentrations within 4-8 hours (IM).

Excretion
Via urine (negligible amounts); 3.7-8.5 hours (elimination half-life).

Interferon Alfa-2A Indications / Interferon Alfa-2A Uses

Information Not Available

Interferon Alfa-2A Adverse Reactions / Interferon Alfa-2A Side Effects

Depressive illness, suicidal behaviour, irritability, insomnia, anxiety. Flu-like symptoms. Headache, dizziness, paraesthesia, confusion, impaired concentration, alteration in taste or smell. GI disturbances. Dryness of oropharynx, epistaxis, rhinitis, arrhythmia, sinusitis. Inj site reaction, alopecia, rash, dry skin or pruritus. Conjunctivitis, menstrual irregularity, visual disturbances. Coughing, dyspnoea. Myalgia, joint or bone pain, arthritis or polyarthritis. Bone marrow depression.

Potentially Fatal: Marked increase in triglyceride levels, GI haemorrhage, severe infections, pulmonary infiltrates or pulmonary function impairment.

Precautions

Warnings
Neuropsychiatric, autoimmune, ischemic, and infectious disorders
Interferons may cause or aggravate fatal or life-threatening disorders of this nature. Persistent severe or worsening signs or symptoms may necessitate discontinuation of therapy. Closely monitor patients with periodic clinical and laboratory evaluations.

Special Risk Patients
Administer with caution in patients with severe renal or hepatic disease, cardiac disease, seizure disorders, or compromised CNS function.

Anemia
Leukopenia and thrombocytopenia may occur.

Depression and suicidal behavior
Depression and suicidal behavior including suicidal ideation, suicidal attempts, and suicides reported in association with alfa-interferon treatment.

Dosage reduction
Dosage reduction by 50% or withholding therapy may be needed when severe adverse reactions occur.

Leukopenia and elevation of hepatic enzymes
Leukopenia and elevation of hepatic enzymes occurred frequently.

Neutralizing antibodies
Neutralizing antibodies can develop during alfa-interferon therapy and may contribute to therapeutic failure in some patients. In some studies, development of neutralizing antibodies was more common with interferon alfa-2a than with interferon alfa-2b.

Hypersensitivity
Avoid use in patients with hypersensitivity to mouse immunoglobulin.

Special Precautions

History of depression (monitor for signs). Perform regular neuropsychiatric monitoring. Seizure disorders and/or compromised CNS function. Preexisting or any history of cardiac disease. Monitor CBC prior to and during therapy. Myelosuppression or concurrent use of myelosuppressive drugs. Hypothyroidism, hyperthyroidism, DM. Perform ophthalmological exam on patients with preexisting ophthalmologic disorders (e.g. diabetic or hypertensive retinopathy). Monitor patients with impaired renal function. Creatinine clearance <50 ml/min. May impair ability to drive or operate machinery. Pregnancy and lactation.

Other Drug Interactions

Reduces clearance of theophylline. Enhanced myelosuppression with other myelosuppressive drugs (e.g. zidovudine). Drugs metabolised by CYP450 pathway (monitor for changes in pharmacologic or adverse effects of concomitant drug). Increased risk of toxicity of centrally acting drugs. Increased risk of renal failure with interleukin-2.

Other Interactions

Information Not Available

Dosage

Subcutaneous
Renal cell carcinoma
Adult: As an adjunct to cytotoxic chemotherapy: In an escalating dose of 3 million units 3 times wkly for 1 week, then 9 million units 3 times wkly for 1 week, then 18 million units 3 times weekly thereafter for 3-12 months.

Subcutaneous
Chronic hepatitis B
Adult: 2.5-5 million units/m2 3 times/weeks for 4-6 months.

Subcutaneous
Chronic hepatitis C
Adult: 3-4.5 million units 3 times wkly for 6 months when used with ribavirin. As monotherapy: Initial: 3-6 million units 3 times weekly for 6 mth followed by 3 million units 3 times weekly for an additional 6 months, or 3 million units 3 times weekly for 12 months.

Subcutaneous
Hairy cell leukaemia
Adult: 3 million units daily for 16-24 weeks. Maintenance: 3 million units 3 times/week. May continue treatment for up to 24 weeks.

Subcutaneous
AIDS-related Kaposi's sarcoma
Adult: In an escalating dose of 3 million units daily for 3 days, 9 million units daily for 3 days, 18 million units daily for 3 days, and 36 million units daily, if tolerated, on days 10-84. thereafter the max tolerated dose (up to 36 million units) may be given 3 times weekly.

Subcutaneous
Chronic myeloid leukaemia
Adult: In an escalating dose of 3 million units daily for 3 days, 6 million units daily for 3 days, and 9 million units daily thereafter. For responders after 12 weeks: Continue treatment until a complete haematological response is achieved or for a max of 18 months; for those who achieve a complete haematological response: Continue on 9 million units daily (at least 9 million units 3 times weekly) in order to achieve a cytogenetic response.

Subcutaneous
Follicular lymphoma
Adult: As an adjunct to chemotherapy: 6 million units/ m2 daily on days 22-26 of each 28-day chemotherapy cycle.

Subcutaneous
Cutaneous T-cell lymphoma
Adult: In an escalating dose of 3 million units daily for 3 days, then 9 million units daily for 3 days, and then 18 million units daily to complete 12 weeks of treatment. Thereafter, the max tolerated dose (up to 18 million units) is given 3 times weekly for at least 12 months in responders.

Subcutaneous
Melanoma
Adult: 3 million units 3 times/week for 18 months. Start treatment no later than 6 weeks after surgery.

Food(before/after)

Information Not Available

Interferon Alfa-2A and Pregnancy

Caution when used during pregnancy

Interferon Alfa-2A and Lactation

Caution when used during lactation

Interferon Alfa-2A and Children

Information Not Available

Interferon Alfa-2A and Geriatic

Information Not Available

Interferon Alfa-2A and Other Contraindications

Hypersensitivity. Autoimmune hepatitis, hepatic decompensation.

Storage

Subcutaneous
Store in a refrigerator at 2-8°C (36-46°F).

Lab interference

Subcutaneous
Store in a refrigerator at 2-8°C (36-46°F).