Pronunciation: IN-ter-FEER-on BAY-ta
- Powder for injection, lyophilized 33 mcg (6.6 million units)
- Prefilled syringe 30 mcg per 0.5 mL
- Prefilled syringe 8.8 mcg per 0.2 mL
- Prefilled syringe 22 mcg per 0.5 mL
- Prefilled syringe 44 mcg per 0.5 mL
Has antiviral, antiproliferative, and immunoregulatory activities. Binds to specific cell membrane receptors that induce the expression of a number of gene products that mediate the biological actions of interferon beta-1a.
T max is 3 to 15 h ( Avonex ). C max is 5.1 units/mL; AUC 0 to 96 is 294 units•h/mL; T max is 16 h ( Rebif ).
The t ½ is 10 h ( Avonex ). Total Cl is approximately 33 to 55 L/h; t ½ is 69 h ( Rebif ).
Indications and Usage
Treatment of relapsing forms of multiple sclerosis to slow accumulation of physical disability and decrease the frequency of clinical exacerbations.
Hypersensitivity to natural or recombinant interferon beta, human albumin, or any other component of the formulation.
Dosage and AdministrationAdults Avonex
IM 30 mcg once weekly.Rebif
Subcutaneous Titrate dose to 22 or 44 mcg 3 times/wk.Titration schedule for 22 mcg
Wk 1 and 2, administer 4.4 mcg 3 times/wk. Wk 3 and 4, administer 11 mcg 3 times/wk. Wk 5 and on, administer 22 mcg 3 times/wk.Titration schedule for 44 mcg
Wk 1 and 2, administer 8.8 mcg 3 times/wk. Wk 3 and 4, administer 22 mcg 3 times/wk. Wk 5 and on, administer 44 mcg 3 times/wk.
- Administer via IM route only. Not for intradermal, subcutaneous, or IV administration.
- Rotate injection sites (thighs and upper arms). Use a different area from where last injection was administered. Do not inject into areas where the skin is infected, tender, bruised, red, or hard.
- Allow prefilled syringe to warm to room temperature before administering. Do not warm using external heat source (eg, hot water).
- Reconstitute powder for injection using supplied diluent only. Swirl vial gently to dissolve. Do not shake vial.
- Reconstituted solution should be clear to slightly yellow.
- Do not administer if particulate matter, cloudiness, or discoloration is noted.
- Withdraw prescribed dose into syringe for injection and administer immediately or within 6 h if stored in refrigerator (36° to 46°F) after reconstitution.
- Vials contain no preservative. Discard any unused portion. Do not combine unused portions.
- Administer via subcutaneous route only. Not for intradermal, IM, or IV administration.
- Rotate injection sites (buttocks, thighs, abdomen, back of arms). Use a different area from where last injection was administered. Do not inject into areas where the skin is tender, bruised, red, or hard.
- Do not mix with other drug solutions.
Store prefilled syringes and unopened vials in refrigerator (36° to 46°F). Do not freeze. If a refrigerator is not available, unopened vials, but not prefilled syringes, may be stored at temperatures at or less than 77°F for up to 30 days, away from heat and light. Once warmed to room temperature, prefilled syringe must be used within 12 h.Rebif
Store prefilled syringes in refrigerator (36° to 46°F). Do not freeze. If a refrigerator is not available, prefilled syringes may be stored at temperatures at or less than 77°F for up to 30 days, away from heat and light.
Drug InteractionsMyelosuppressive agents
Because of potential to cause neutropenia and lymphopenia, monitor patients during concomitant therapy.
Laboratory Test Interactions
None well documented.
Vasodilation (2%); cardiomyopathy, cardiomyopathy with CHF, CHF (postmarketing).
Headache (58%); depression (20%); dizziness (14%); migraine (5%); suicidal tendencies (4%); psychiatric disorders, seizures (postmarketing).Rebif
Headache (70%); fatigue (41%); depression (25%); hypertonia (7%); abnormal coordination, seizures, somnolence (5%); suicidal ideation.
Alopecia (4%); rash including vesicular rash (postmarketing).Rebif
Erythematous rash (7%); maculopapular rash (5%).
Sinusitis (14%); eye disorder (4%).Rebif
Abnormal vision (13%); xerophthalmia (3%).
Hyperthyroidism, hypothyroidism (postmarketing).Rebif
Thyroid disorder (6%).
Nausea (23%); abdominal pain (8%); toothache (3%).Rebif
Abdominal pain (22%); dry mouth (5%).
UTIs (17%); abnormal urine constituents (3%); menorrhagia, metrorrhagia (postmarketing).Rebif
Micturition frequency (7%); urinary incontinence (4%).
Anemia (4%); decreased peripheral blood counts in all cell lines including pancytopenia and thrombocytopenia, idiopathic thrombocytopenia (postmarketing).Rebif
Leukopenia (36%); lymphadenopathy (12%); thrombocytopenia (8%); anemia (5%).
Autoimmune hepatitis, elevated serum hepatic enzymes, hepatic injury including hepatic failure, hepatitis (postmarketing).Rebif
Increased ALT (27%); increased AST (17%); abnormal hepatic function (9%); bilirubinemia (3%); severe liver dysfunction including hepatic failure requiring transplantation (postmarketing).
Inflammation at subcutaneous site (52%); injection-site pain (8%); injection-site ecchymosis, injection-site inflammation (6%); injection-site reaction (3%); atrophy, edema, hemorrhage, injection-site abscess or cellulitis, injection-site necrosis (postmarketing).Rebif
Injection-site reaction (92%); injection-site necrosis (3%).
Myalgia (29%); arthralgia (9%).Rebif
Back pain, myalgia (25%); skeletal pain (15%).
Upper respiratory tract infection (14%); bronchitis (8%).
Flu-like symptoms (49%); asthenia (24%); pain (23%); fever (20%); chills (19%); infection (7%); chest pain, neutralizing antibodies (5%); anaphylaxis (postmarketing).Rebif
Flu-like symptoms (59%); neutralizing antibodies (31%); fever (28%); rigors (13%); chest pain (8%); malaise (5%); anaphylaxis.
Ensure that Hgb, CBC with differential, platelet count, and blood chemistries, including LFTs, are performed before initiating therapy, at 1, 3, and 6 mo after starting therapy, and then periodically thereafter. Ensure that thyroid function tests are performed before starting therapy and every 6 mo during therapy in patients with thyroid dysfunction.
Category C .
Safety and efficacy in children younger than 18 yr of age not established.
Use with caution because of greater frequency of decreased hepatic, renal, or cardiac function, and concomitant diseases or other drug therapy ( Rebif ).
Product contains albumin, a derivative of human blood; therefore, there is a remote risk for transmission of viral diseases.
Anaphylaxis has been reported as a rare complication.
Autoimmune disorders of multiple target organs have been reported, including idiopathic thrombocytopenia, hyperthyroidism, and hypothyroidism, and rare cases of autoimmune hepatitis. Monitor for signs of these disorders and implement appropriate treatment when observed ( Avonex ).
Cardiomyopathy and CHF
Patients with cardiac disease, such as angina, CHF, or arrhythmia, should be closely monitored for worsening of clinical condition during initiation and continuation of treatment ( Avonex ).
Decreased peripheral blood counts
Decreased peripheral blood counts in all cell lines, including rare pancytopenia and thrombocytopenia, may occur ( Avonex ).
Severe liver function injury, leading to hepatic failure requiring liver transplantation, may occur; asymptomatic elevation of hepatic transaminases has occurred.
Use caution when administering to patients with preexisting seizure disorder.
Suicidal ideation occurred in clinical trials. Report depression and suicidal ideation immediately.
- Advise patient, family, or caregiver that medication is not a cure for multiple sclerosis, but it may decrease the number of flare-ups and slow the development of some of the physical disabilities caused by multiple sclerosis.
- Advise patient or caregiver to review the Medication Guide before using and with each refill.
- If patient or caregiver will be administering at home, ensure that he/she understands how to store, prepare, and administer the dose, and how to dispose of used equipment and supplies. If possible, first injection should be performed under supervision of a qualified health professional.
- Advise patient not to change the dose or stop taking unless advised by health care provider.
- Advise patient that flu-like symptoms are common and that OTC fever and pain reducers (eg, acetaminophen, ibuprofen) can be used to relieve fever and muscle aches.
- Advise patient to notify health care provider immediately if any of the following occur: drainage of fluid, injection-site reaction with break in skin and blue-black discoloration, severely depressed mood, suicidal ideation, swelling.
- Advise patient to contact health care provider if experiencing bothersome adverse reactions or any unusual problems.
- Advise women of childbearing potential to use effective contraception during treatment because of the abortifacient potential of these medications.
- Advise patient that if a dose is missed to take it as soon as possible and then continue regular schedule the following week.
- Instruct patient to rotate injection sites as described in the Medication Guide to minimize likelihood of severe injection-site reactions.
- Caution patient or caregiver that the prefilled syringe cap contains dry natural rubber that should not be handled by individuals sensitive to latex.
- Advise patient that if a dose is missed to take it as soon as possible and to schedule next dose approximately 48 h later.
- Instruct patient to rotate injection sites as described in the Medication Guide to minimize likelihood of severe injection-site reactions or tissue necrosis.
Copyright © 2009 Wolters Kluwer Health.