logo

Interferon's

Background

Interferons are a family of proteins, produced by nucleated cells, that have anti-viral, anti-proliferative, and immune-regulating activity. There are 16 known subtypes of alpha interferons. Interferons interact with cells through high affinity cell surface receptors. Multiple effects have been detected: inhibition of cellular growth, alteration in surface antigen expression, increased phagocytic activity of macrophages, augmentation of cytotoxicity of lymphocytes for target cells.
Interferon Alfa-2A (Roferon-A) Interferon Alfa-2b (Intron-A)
Interferon Alfa-2b and Ribavirin combo Pack (Rebetron) Interferon Alfa-N3 (Alferon N)
Interferon Beta-1A (Avonex) Interferon Beta-1B (Betaseron)
Please see package insert for additional information and possible updates. The authors make no claims of the accuracy of the information contained herein; and these suggested doses are not a substitute for clinical judgment. Neither GlobalRPh Inc. nor any other party involved in the preparation of this program shall be liable for any special, consequential, or exemplary damages resulting in whole or part from any user's use of or reliance upon this material. PLEASE READ THE DISCLAIMER CAREFULLY BEFORE ACCESSING OR USING THIS SITE. BY ACCESSING OR USING THIS SITE, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS SET FORTH IN THE DISCLAIMER.    [  Read the disclaimer    |   <<Back     ]

Interferon Alfa-2A (Roferon-A): top of page

CLINICAL PHARMACOLOGY
The mechanism by which Interferon alfa-2a, recombinant, or any other interferon, exerts antitumor or antiviral activity is not clearly understood. However, it is believed that direct antiproliferative action against tumor cells, inhibition of virus replication and modulation of the host immune response play important roles in antitumor and antiviral activity.

INDICATIONS AND USAGE
Roferon-A is indicated for the treatment of chronic hepatitis C and hairy cell leukemia in patients 18 years of age or older. In addition, it is indicated 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
Roferon-A is indicated 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 biopsy and 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 Roferon-A.

Dosing (Adults):
Hairy cell leukemia: SubQ, I.M.: 3 million units/day for 16-24 weeks, then 3 million units 3 times/week for up to 6-24 months

Chronic myelogenous leukemia (CML): SubQ, I.M.: 9 million units/day, continue treatment until disease progression

AIDS-related Kaposi's sarcoma: SubQ, I.M.: 36 million units/day for 10-12 weeks, then 36 million units 3 times/week; to minimize adverse reactions, can use escalating dose (3-, 9-, then 18 million units each day for 3 days, then 36 million units daily thereafter).

Hepatitis C: SubQ, I.M.: 3 million units 3 times/week for 12 months

Administration
SubQ administration is suggested for those who are at risk for bleeding or are thrombocytopenic; rotate SubQ injection site; patient should be well hydrated

Baseline ophthalmologic exam should be performed in all patients, with periodic reassessment in patients with impairment. Patients with thyroid dysfunction should be monitored by TSH levels at baseline and every 3 months during therapy.
Chronic hepatitis C: Monitor ALT (at baseline, after 2 weeks, and monthly thereafter) and HCV-RNA (particularly in first 3 months of therapy)

CML/hairy cell leukemia: Hematologic monitoring should be performed monthly.

SUPPLIED:
Injection, solution, [single-dose prefilled syringe; SubQ use only]: 3 million units/0.5 mL (0.5 mL); 6 million units/0.5 mL (0.5 mL); 9 million units/0.5 mL (0.5 mL)

Interferon Alfa-2b (Intron-A):  top of page

General
The interferons are a family of naturally occurring small proteins and glycoproteins with molecular weights of approximately 15,000 to 27,600 daltons produced and secreted by cells in response to viral infections and to synthetic or biological inducers.

Dosing (Adults)
Hairy cell leukemia: I.M., SubQ: 2 million units/m 2 3 times/week for 2-6 months

Lymphoma (follicular): SubQ: 5 million units 3 times/week for up to 18 months

Malignant melanoma: 20 million units/m 2 I.V. for 5 consecutive days per week for 4 weeks, then 10 million units/m 2 SubQ 3 times/week for 48 weeks

AIDS-related Kaposi's sarcoma: I.M., SubQ: 30 million units/m 2 3 times/week

Chronic hepatitis B: I.M., SubQ: 5 million units/day or 10 million units 3 times/week for 16 weeks

Chronic hepatitis C: I.M., SubQ: 3 million units 3 times/week for 16 weeks. In patients with normalization of ALT at 16 weeks, continue treatment for 18-24 months; consider discontinuation if normalization does not occur at 16 weeks. Note: May be used in combination therapy with ribavirin in previously untreated patients or in patients who relapse following alpha interferon therapy; refer to Interferon Alfa-2b and Ribavirin Combination Pack monograph.

Condyloma acuminata: Intralesionally: 1 million units/lesion (maximum: 5 lesions/treatment) 3 times/week (on alternate days) for 3 weeks; may administer a second course at 12-16 weeks
--------------------------------------

Dosage adjustment for toxicity:
Lymphoma (follicular):
Severe toxicity (neutrophils <1000 cells/mm 3 or platelets <50,000 cells/mm 3 ): Reduce dose by 50% or temporarily discontinue

AST/ALT >5 times ULN: Permanently discontinue

Hairy cell leukemia:
Severe toxicity: Reduce dose by 50% or temporarily discontinue; permanently discontinue if persistent or recurrent severe toxicity is noted

Hepatitis B or C:
WBC <1500 cells/mm 3 , granulocytes <750 cells/mm 3 , or platelet count <50,000 cells/mm 3 : Reduce dose by 50%

WBC <1000 cells/mm 3 , granulocytes <500 cells/mm 3 , or platelet count <25,000 cells/mm 3 : Permanently discontinue

Kaposi sarcoma: Severe toxicity: Reduce dose by 50% or temporarily discontinue

Malignant melanoma:
Severe toxicity (neutrophils <500 cells/mm 3 or AST/ALT >5 times ULN): Reduce dose by 50% or temporarily discontinue.

Neutrophils <250 cells/mm 3 or AST/ALT >10 times ULN: Permanently discontinue.

--------------------------------------

Administration
SubQ: Suggested for those who are at risk for bleeding or are thrombocytopenic. Rotate SubQ injection site. Patient should be well hydrated. Reconstitute with recommended amount of SWFI and agitate gently; do not shake. Note: Different vial strengths require different amounts of diluent. Not every dosage form is appropriate for every indication; refer to manufacturer's labeling.

SUPPLIED:
Injection, powder for reconstitution: 10 million units; 18 million units; 50 million units.
Injection, solution [multidose prefilled pen]:
Delivers 3 million units/0.2 mL (1.5 mL) [delivers 6 doses; 18 million units]
Delivers 5 million units/0.2 mL (1.5 mL) [delivers 6 doses; 30 million units]
Delivers 10 million units/0.2 mL (1.5 mL) [delivers 6 doses; 60 million units]
Injection, solution [multidose vial]: 6 million units/mL (3 mL); 10 million units/mL (2.5 mL)
Injection, solution [single-dose vial]: 10 million units/ mL (1 mL)

Interferon Alfa-2b and Ribavirin combo Pack (Rebetron) top of page

Dosing (Adults):
Chronic hepatitis C: Recommended dosage of combination therapy:  
Intron® A
: SubQ: 3 million int. units 3 times/week and  
Rebetol® capsule
: Oral:   </= 75 kg (165 lb): 1000 mg/day (two 200 mg capsules in the morning and three 200 mg capsules in the evening).    >75 kg: 1200 mg/day (three 200 mg capsules in the morning and three 200 mg capsules in the evening)

Treatment duration recommendations:
Following relapse after alpha interferon monotherapy: 24 weeks.
Previously untreated: 24-48 weeks (individualized based on response, tolerance, and baseline characteristics).
Consider discontinuing therapy in any patient not achieving HCV-RNA below the limit of assay detection by 24 weeks.
=======================================

Dosing adjustment for toxicity (adults):
Anemia (RBC depression):  Patient without cardiac history:
Hemoglobin <10 g/dL:
Adults: Decrease dose to 600 mg/day

Hemoglobin <8.5 g/dL: Permanently discontinue treatment

Patient with cardiac history:
Hemoglobin has >/= 2 g/dL decrease during any 4-week period of treatment:

Adults: Decrease dose to ribavirin to 600 mg/day and decrease interferon-alfa 2b dose to 1.5 million int. units 3 times/week.

Hemoglobin <12 g/dL after 4 weeks of reduced dose: Permanently discontinue treatment

WBC, neutrophil, or platelet depression:
WBC <1500 cells/mm 3 , neutrophils <750 cells/mm 3 , or platelet count <50,000 cells/mm 3 (<80,000 cells/ mm 3 in children): Reduce interferon alfa-2b dose to 1.5 million int. units 3 times/week (50% reduction)

WBC <1000 cells/mm 3 , neutrophils <500 cells/mm 3 , or platelet count <25,000 cells/mm 3 (<50,000 cells/mm 3 in children): Permanently discontinue therapy

Dosage adjustment in renal impairment:
Patients with Clcr<50 mL/minutes should not receive ribavirin.

=======================================

Administration
Capsule should not be opened, crushed, chewed, or broken. Capsules are not for use in children <5 years of age. Use oral solution for children 3-5 years, those </= 25 kg, or those who cannot swallow capsules.

Interferon Alfa-N3 (Alferon N):   top of page

INDICATIONS:
Patients >/= 18 years of age: Intralesional treatment of refractory or recurring genital or venereal warts (condylomata acuminata)


DOSING (Adults): Inject 250,000 units (0.05 mL) in each wart twice weekly for a maximum of 8 weeks; therapy should not be repeated for at least 3 months after the initial 8-week course of therapy


SUPPLIED:
Injection, solution: 5 million int. units (1 mL)

Interferon Beta-1A (Avonex):  top of page

INDICATIONS:
Treatment of relapsing forms of multiple sclerosis (MS)

DOSING (Adults): Note: Analgesics and/or antipyretics may help decrease flu-like symptoms on treatment days:
I.M. (Avonex®): 30 mcg once weekly

SubQ (Rebif®): Doses should be separated by at least 48 hours:
Target dose 44 mcg 3 times/week:
Initial: 8.8 mcg (20 % of final dose) 3 times/week for 8 weeks
Titration: 22 mcg (50% of final dose) 3 times/week for 8 weeks
Final dose: 44 mcg 3 times/week

Target dose 22 mcg 3 times/week:
Initial: 4.4 mcg (20 % of final dose) 3 times/week for 8 weeks
Titration: 11 mcg (50% of final dose) 3 times/week for 8 weeks
Final dose: 22 mcg 3 times/week

Dosage adjustment in hepatic impairment: Rebif®: If liver function tests increase or in case of leukopenia: Decrease dose 20% to 50% until toxicity resolves

SUPPLIED:
Combination package [preservative free] (Rebif® Titration Pack):
Injection, solution: 8.8 mcg/0.2 mL (0.2 mL) [6 prefilled syringes; contains albumin]
Injection, solution: 22 mcg/0.5 mL (0.5 mL) [6 prefilled syringes; contains albumin]

Injection, powder for reconstitution (Avonex®): 33 mcg [6.6 million units; provides 30 mcg/mL following reconstitution] [contains albumin; packaged with SWFI, alcohol wipes, and access pin and needle]

Injection, solution (Avonex®): 30 mcg/0.5 mL (0.5 mL) [albumin free; prefilled syringe; syringe cap contains latex; packaged with alcohol wipes, gauze pad, and adhesive bandages]

Injection, solution [preservative free] (Rebif®): 22 mcg/0.5 mL (0.5 mL) [prefilled syringe; contains albumin]; 44 mcg/0.5 mL (0.5 mL) [prefilled syringe; contains albumin]

Interferon Beta-1B (Betaseron):  top of page

INDICATIONS:
Treatment of relapsing forms of multiple sclerosis (MS)

DOSING (Adults):
SubQ:
Children <18 years: Not recommended
Adults: 0.25 mg (8 million units) every other day

Administration
Withdraw 1 mL of reconstituted solution from the vial into a sterile syringe fitted with a 27-gauge needle and inject the solution subcutaneously; sites for self-injection include arms, abdomen, hips, and thighs

SUPPLIED:
Injection, powder for reconstitution [preservative free]: 0.3 mg [9.6 million units]
 

Reference(s)

National Institutes of Health, U.S. National Library of Medicine, DailyMed Database.
Provides access to the latest drug monographs submitted to the Food and Drug Administration (FDA). Please review the latest applicable package insert for additional information and possible updates.  A local search option of this data can be found here.

Disclaimer

Listed dosages are for - Adult patients ONLY. PLEASE READ THE DISCLAIMER CAREFULLY BEFORE ACCESSING OR USING THIS SITE. BY ACCESSING OR USING THIS SITE, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS SET FORTH IN THE DISCLAIMER. GlobalRPH does not directly or indirectly practice medicine or provide medical services and therefore assumes no liability whatsoever of any kind for the information and data accessed through the Service or for any diagnosis or treatment made in reliance thereon.

David F. McAuley, Pharm.D., R.Ph.  GlobalRPh Inc.
more Career Center image description
Medical Calculators - A thru Z
Lab Values - A thru Z