Interferon Alfa

Uses

Interferon Alfa-2a is used for the treatment of chronic hepatitis C and hairy cell leukemia in patients 18 years of age or older. In addition, it is used for chronic phase, Philadelphia chromosome (Ph) positive chronic myelogenous leukemia (CML) patients who are minimally pretreated (within 1 year of diagnosis).

For Patients With Chronic Hepatitis C: Interferon Alfa-2a is used for use in patients with chronic hepatitis C diagnosed by HCV antibody and/or a history of exposure to hepatitis C who have compensated liver disease and are 18 years of age or older. A liver biopsyand a serum test for the presence of antibody to HCV should be performed to establish the diagnosis of chronic hepatitis C. Other causes of hepatitis, including hepatitis B, should be excluded prior to therapy with Interferon Alfa-2a .

Interferon Alfa is also used to associated treatment for these conditions: Follicular Non-Hodgkin's Lymphoma, Hepatitis C Viral Infection, Malignancies, Hematologic, Melanoma, Malignant, Renal Cell Adenocarcinoma, Viral Hepatitis B

How Interferon Alfa works

Natural alpha interferon offers multiple subtypes of interferon which may work together as a 'cocktail-in-one', while recombinant versions only exhibit a single subtype." Viragen offers MultiferonT at a cost which is competitive with recombinant interferon regimens.

Natural alpha interferon contains the multiple subtype composition that is characteristic of interferon produced by the human body. It is believed that this results in a broader spectrum of specific anti-viral and immunoregulatory activity with the subtypes acting synergistically to give a wide-ranging response.

Dosage

Interferon Alfa dosage

Renal cell carcinoma: In an escalating dose of 3 million unit 3 times/week for 1 week, then 9 million unit 3 times/week for 1 week, then 18 million unit 3 times/week thereafter for 3-12 month.

Chronic hepatitis B: 2.5-5 million unit/m2 3 times/week for 4-6 month. Chronic hepatitis C withribavirin: 3-4.5 million unit 3 times/week for 6 month. Monotherapy: 3 million unit 3 times/ week for 12 month. Hairy cell leukaemia 3 million unit/day for 16-24 week. Maintenance: 3 million unit 3 times/week, up to 24 week.

AIDS related Kaposi's sarcoma: In an escalating dose of 3 million unit/day for 3 days, 9 million unit/day for 3 days, 18 million unit/day for 3 days, and 36 million unit/day (if tolerated) on days 10-84. thereafter max tolerated dose (up to 36 million u) 3 times/week.

Chronic myeloid leukaemia: In an escalating dose of 3 million unit/day for 3 days, 6 million unit/day for 3 days, and 9 million unit/day thereafter. For responders after 12 week: Continue treatment until haematological response is complete or up to 18 month. Follicular lymphoma As adjunct to chemotherapy: 6 million unit/m2/day on days 22-26 of each 28-day cycle.

Cutaneous T-cell lymphoma: In an escalating dose of 3 million unit/day for 3 days, then 9 million unit/day for 3 days, and then 18 million unit/day to complete 12 week of treatment. Thereafter, max tolerated dose (up to 18 million unit) 3 times/week for at least 12 month in responders.

Melanoma: 3 million unit 3 times/week for 18 month. Start treatment no later than 6 week after surgery.

Side Effects

Depressive illness, suicidal behaviour, irritability, insomnia, anxiety. Flu-like symptoms. Headache, dizziness, paraesthesia, confusion, impaired concentration, alteration in taste or smell. Gl 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.

Precaution

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.

Interaction

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.

Elimination Route

Reticulo-endothilial system, kidneys and liver.

Pregnancy & Breastfeeding use

Pregnancy Category: Interferon Alfa-2a should be administered only if the benefit to the woman justifies the potential risk to the foetus. Although animal tests do not indicate that Roferon-A is a teratogen, harm to the foetus from use during pregnancy cannot be excluded. When doses greatly in excess of the recommended clinical dose were administered to pregnant rhesus monkeys in the early to mid foetal period, an abortifacient effect was observed.

Nursing mothers: It is not known whether Interferon Alfa-2a is secreted in human milk. A decision must be taken whether to suspend breast-feeding or to discontinue the medicine, taking into account the importance of the medicine to the mother.

Contraindication

Interferon Alfa-2a is contraindicated in

• patients with a history of hypersensitivity to recombinant interferon alfa-2a or any component of the preparation.
• patients with severe pre-existing cardiac disease or with any history of cardiac illness. No direct cardiotoxic effect has been demonstrated, but it is likely that acute, self-limiting toxicities (e.g. fever, chills) frequently associated with administration of Interferon Alfa-2a may exacerbate pre-existing cardiac conditions.
• severe renal, hepatic or myeloid dysfunction.
• seizure disorders and/or compromised central nervous system function.
• chronic hepatitis with advanced, decompensated hepatic disease.
• chronic hepatitis patients who are being or have recently been treated with immunosuppressive agents, excluding short-term "steroid withdrawal".
• CML patients with an HLA-identical relative who are potential candidates for allogeneic bone marrow transplantation in the immediate future.
• neonates, children up to 3 years, and premature infants. Interferon Alfa-2a solution for injection contains benzyl alcohol. There have been reports of permanent neuropsychiatric deficits and multiple system organ failure associated with benzyl alcohol.

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