♦Interferon-alfa-2b

(in-ter-feer’-on)

Intron-A,

IFN-alpha 2

Pregnancy Category C

Mechanism of Action

Interferon exerts antitumor activities through antiviral replication, immunomodulatory, and antiproliferative biologic effects. Its direct antiproliferative properties may explain its activity in certain malignancies.

Indications

Hairy cell leukemia, condylomata acuminata, AIDS-related Kaposi’s sarcoma, chronic hepatitis non-A, non-B/C, and chronic hepatitis B, and as adjuvant treatment for malignant melanoma with no evidence of disease but at high risk for recurrence. All patients must be 18 years or older.

Metabolism/Excretion

Metabolized in the kidneys; excretion unknown. Elimination half-life after SQ or IM injection: about 2 to 3 hours; serum concentrations peak from 3 to 12 hours after injection and are undetectable by 16 hours after injection. Elimination half-life after IV infusion: about 2 hours; serum concentrations peak at the end of a 30-minute infusion and are undetectable by 4 hours.

Dosage Range

Adult

♦ Hairy cell leukemia: Two million IU/m² three times a week injected IM or SQ. Continue treatment unless rapid progression of disease or severe intolerance occurs. May need to reduce dose by half or temporarily withhold until adverse reactions resolve.

♦ Condylomata acuminata: Reconstitute vial containing 10 million IU powder for injection with 1 mL diluent (bacteriostatic water); then inject 1.0 million IU (0.1 mL of reconstituted solution) into each lesion (intralesionally) three times a week for 3 weeks using a tuberculin syringe with a 25- to 20-gauge needle. Maximum response may take up to 4 to 8 weeks after initiation of treatment.
A second course of treatment may be needed if a satisfactory response is not achieved after 12 to 16 weeks.

♦ AIDS-related Kaposi’s sarcoma: Thirty million IU/m² three times a week injected SQ or IM. Continue treatment until complete response is achieved. Discontinue treatment with severe opportunistic infection or adverse reactions. May need to reduce dose by half or temporarily with-hold until adverse reactions resolve.

♦ Chronic hepatitis non-A, non-B/C: Three million IU/m² three times a week injected SQ or IM. Those responding to treatment should complete 6 months of treatment. May consider discontinuing treatment if no response is noted after 16 weeks of treatment. May need to reduce dose by half or temporarily withhold until adverse reactions resolve.

♦ Chronic hepatitis B: Thirty to 35 million IU/m² per week injected SQ or IM, either as 5 million IU/m² daily or as 10 million IU/m² three times a week for 16 weeks. May need to reduce dose by half or temporarily withhold until adverse reactions resolve.

♦ Malignant melanoma: Induction treatment is 20 million IU/m² for 5 consecutive days per week for 4 weeks as an IV infusion. Maintenance dose is 10 million IU/m² three times a week injected SQ for 48 weeks. If granulocytes are <500/mm³ or aspartate transferase/alanine transferase is >5 times the upper normal limit, withhold treatment until laboratory values return to normal.

Pediatric

Safety and efficacy not established.

Drug Preparation/Stability

Store powder and solution for injection in the refrigerator at 2° to 8°C (36° to 46°F). After reconstitution of powder, solution is stable for 1 month if refrigerated. Do not shake or freeze.

Only gold members can continue reading. Log In or Register to continue