Dosing & Uses
Dosage Forms & Strengths
prefilled IM syringe (Avonex)
- 30mcg/0.5mL
prefilled IM autoinjector pen (Avonex)
- 30mcg/0.5mL
powder for injection (Avonex)
- 30mcg/vial (30mcg/0.5 mL reconstituted)
prefilled SC syringes titration pack (Rebif)
- 8.8mcg/0.2mL (6 syringes)
- 22mcg/0.5mL (6 syringes)
prefilled SC syringe (Rebif)
- 22mcg/0.5mL
- 44mcg/0.5mL
prefilled SC autoinjector (Rebif Rebidose)
- 8.8mcg/syringe
- 22mcg/syringe
- 44mcg/syringe
Multiple Sclerosis
Indicated for the treatment of relapsing forms of multiple sclerosis (including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease) to slow accumulation of physical disability and decrease frequency of clinical exacerbations
Avonex
- 30 mcg IM qWk
- May be titrated using the AVOSTARTGRIP titration kit with prefilled IM syringes starting with 7.5 mcg IM for first week, to reduce flu-like symptoms; increase by 7.5 mcg/week for next 3 weeks until recommended dose of 30 mcg/week
- Administration: Rotate IM injection sites between upper thighs and arms
Rebif 44 mcg target dose
- Weeks 1-2: 8.8 mcg SC 3 times/wk (at least 48 hr apart)
- Weeks 3-4: 22 mcg SC 3 times/wk
- Weeks 5+: 44 mcg SC 3 times/wk
- Administration: Abdomen (except waistline), thigh, arm, buttocks
Rebif 22 mcg target dose
- Weeks 1-2: 4.4 mcg SC 3 times/wk (at least 48 hr apart)
- Weeks 3-4: 11 mcg SC 3 times/wk
- Weeks 5+: 22 mcg SC 3 times/wk
- Administration: Abdomen (except waistline), thigh, arm, buttocks
Hepatic Impairment
Rebif: Decrease dose 20-50% if liver function tests increase or leukopenia observed
Dosage Forms & Strengths
prefilled IM syringe (Avonex)
- 30mcg/0.5 mL
prefilled IM autoinjector pen (Avonex)
- 30mcg/0.5mL
powder for injection (Avonex)
- 30mcg/vial (30mcg/0.5 mL reconstituted)
prefilled SC syringes titration pack (Rebif)
- 8.8mcg/0.2mL (6 syringes)
- 22mcg/0.5mL (6 syringes)
prefilled SC syringe (Rebif)
- 22mcg/0.5mL
- 44mcg/0.5mL
prefilled SC autoinjector (Rebif Rebidose)
- 8.8mcg/syringe
- 22mcg/syringe
- 44mcg/syringe
Multiple Sclerosis (Off-label)
Safety and efficacy not established
Limited data suggests to titrate as in adults
Avonex
- 30 mcg IM qWk
- May be titrated using the AVOSTARTGRIP titration kit with prefilled IM syringes starting with 7.5 mcg IM for first week, to reduce flu-like symptoms; increase by 7.5 mcg/week for next 3 weeks until recommended dose of 30 mcg/week
- Administration: Rotate IM injection sites between upper thighs and arms
Rebif 44 mcg target dose
- Weeks 1-2: 8.8 mcg SC 3 times/wk (at least 48 hr apart)
- Weeks 3-4: 22 mcg SC 3 times/wk
- Weeks 5+: 44 mcg SC 3 times/wk
- Administration: Abdomen (except waistline), thigh, arm, buttocks
Rebif 22 mcg target dose
- Weeks 1-2: 4.4 mcg SC 3 times/wk (at least 48 hr apart)
- Weeks 3-4: 11 mcg SC 3 times/wk
- Weeks 5+: 22 mcg SC 3 times/wk
- Administration: Abdomen (except waistline), thigh, arm, buttocks
- Monitor: Hgb, WBC, Plt, LFTs
Multiple sclerosis
Avonex
30 mcg IM qWk
May be titrated using the AVOSTARTGRIP titration kit with prefilled IM syringes starting with 7.5 mcg IM for first week, to reduce flu-like symptoms; increase by 7.5 mcg/week for next 3 weeks until recommended dose of 30 mcg/week
Administration: Rotate IM injection sites between upper thighs and arms
Monitor: Hgb, WBC, Plt, LFTs
Rebif 44 mcg target dose
Weeks 1-2: 8.8 mcg SC 3 times/wk (at least 48 hr apart)
Weeks 3-4: 22 mcg SC 3 times/wkWeeks 5+: 44 mcg SC 3 times/wk
Administration: Abdomen (except waistline), thigh, arm, buttocks
Monitor: Hgb, WBC, Plt, LFTs
Rebif 22 mcg target dose
Weeks 1-2: 4.4 mcg SC 3 times/wk (at least 48 hr apart)
Weeks 3-4: 11 mcg SC 3 times/wk
Weeks 5+: 22 mcg SC 3 times/wk
Administration: Abdomen (except waistline), thigh, arm, buttocks
Monitor: Hgb, WBC, Plt, LFTs
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (4)
- deferiprone
deferiprone, interferon beta 1a. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid use of deferiprone with other drugs known to be associated with neutropenia or agranulocytosis; if an alternative is not possible, monitor absolute neutrophil count more frequently.
- pexidartinib
interferon beta 1a and pexidartinib both increase Other (see comment). Avoid or Use Alternate Drug. Pexidartinib can cause hepatotoxicity. Avoid coadministration of pexidartinib with other products know to cause hepatoxicity.
- pretomanid
interferon beta 1a, pretomanid. Either increases toxicity of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Pretomanid regimen associated with hepatotoxicity. Avoid alcohol and hepatotoxic agents, including herbal supplements and drugs other than bedaquiline and linezolid.
- ropeginterferon alfa 2b
ropeginterferon alfa 2b, interferon beta 1a. Either increases toxicity of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Myelosuppressive agents can produce additive myelosuppression. Avoid use and monitor patients receiving the combination for effects of excessive myelosuppression.
Monitor Closely (10)
- acalabrutinib
acalabrutinib, interferon beta 1a. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may increase risk of myelosuppressive effects.
- ansofaxine
ansofaxine, interferon beta 1a. Either increases effects of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Consider the risk of additive immune system effects when coadministering immunosuppressive therapies with coadministration. When switching from therapies with immune effects, take into account the duration and mechanism of action of these therapies when initiating ofatumumab SC.
- hydroxyurea
interferon beta 1a, hydroxyurea. Other (see comment). Use Caution/Monitor. Comment: Cutaneous vasculitic toxicities (eg, vasculitic ulcerations and gangrene) were reported during therapy with hydroxyurea in patients with a history of, or currently receiving, interferon therapy.
- ifosfamide
ifosfamide, interferon beta 1a. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Ifosfamide may enhance the toxicities of myelosuppressive agents. Monitor for increased risk of myelosuppression.
- isavuconazonium sulfate
interferon beta 1a and isavuconazonium sulfate both decrease immunosuppressive effects; risk of infection. Use Caution/Monitor.
- lomustine
lomustine, interferon beta 1a. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may increase risk of myelosuppressive effects.
- ozanimod
ozanimod, interferon beta 1a. Either increases effects of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Coadministration with immunosuppressive therapies may increase the risk of additive immune effects during therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs in order to avoid unintended additive immunosuppressive effects.
- siponimod
siponimod and interferon beta 1a both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immune effects during such therapy and in the weeks following administration. Siponimod can generally be started immediately after discontinuation of beta interferon.
- tobramycin inhaled
tobramycin inhaled and interferon beta 1a both increase nephrotoxicity and/or ototoxicity. Modify Therapy/Monitor Closely. Avoid concurrent or sequential use to decrease risk for ototoxicity
- zidovudine
interferon beta 1a increases levels of zidovudine by decreasing renal clearance. Use Caution/Monitor. Interferons may enhance potential for adverse effects. Patients should be monitored for signs and symptoms of increased myelosuppression and liver decompensation.
Minor (1)
- natalizumab
interferon beta 1a increases levels of natalizumab by decreasing renal clearance. Minor/Significance Unknown.
Adverse Effects
>10%
Injection site reactions (83% [Rebif]; 28% [Avonex])
Headache (67%)
Flu-like syndrome (61%)
Muscle ache (34%)
Nausea (33%)
URT infection (14%)
Pain (24%)
Fever (23%)
Asthenia (21%)
Diarrhea (16%)
Dizziness (15%)
Infection (11%)
Dyspepsia (11%)
1-10%
Abdominal pain (9%)
Anemia (8%)
Chest pain (6%)
<1%
Aggravation of seizure disorders
Postmarketing Reports
Autoimmune disorders: Drug-induced lupus erythematosus, autoimmune hepatitis
Blood and lymphatic system disorders: Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), hemolytic anemia
Eye disorders: Retinal vascular disorders (ie, retinopathy, cotton wool spots or obstruction of retinal artery or vein)
Skin and subcutaneous tissue disorders: Erythema multiforme, Stevens-Johnson syndrome
Hyperhidrosis
Injection site reactions including necrosis
Warnings
Contraindications
Hypersensitivity to beta interferons, albumin (for albumin-containing formulations)
Cautions
Hepatic impairment, pregnancy, lactation, depression (may cause worsening, suicidal ideation)
Risk of rare but potentially severe hepatic damage
Fllu-like symptoms may occur
Caution in patients with existing cardiovascular disease (angina, heart failure, etc)
Autoimmune disorders (autoimmune hepatitis; idiopathic thrombocytopenia) reported
Efficacy in primary progressive MS not demonstrated conclusively; not recommended
Cases of thrombotic microangiopathy, including thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, some fatal, reported; some cases have been reported several weeks to years after starting interferon beta products; discontinue therapy if clinical symptoms and laboratory findings consistent with TMA occur, and manage as clinically indicated
Injection site reactions
- Injection site reactions, including injection site necrosis, can occur with the use of interferon beta products; in controlled clinical trials, injection site reactions (eg, injection site pain, bruising, or erythema) reported; reactions included injection site inflammation (6%), injection site pain (8%), injection site mass (<1%), nonspecific reactions
- Injection site abscesses and cellulitis and injection site necrosis reported in postmarketing setting with interferon beta products; some cases required treatment with hospitalization for surgical drainage and intravenous antibiotics
- Periodically evaluate patient understanding and use of aseptic self-injection techniques and procedures, particularly if injection site necrosis has occurred
- Whether to discontinue therapy following a single site of necrosis is dependent on extent of necrosis; for patients who continue therapy after injection site necrosis has occurred, avoid administration of the drug into the affected area until it is fully healed; if multiple lesions occur, change injection site or discontinue therapy until healing occurs
Pregnancy & Lactation
Pregnancy
Data from a large population-based cohort study, as well as other published studies over several decades, have not identified a drug-associated risk of major birth defects with use during early pregnancy
Findings regarding a potential risk for low birth weight or miscarriage with use of interferon beta products in pregnancy have been inconsistent
Animal data
- In a study in pregnant monkeys, administration of interferon beta during pregnancy resulted in an increased rate of abortion at doses greater than those used clinically
Lactation
Limited published literature has described the presence of interferon beta-1a products in human milk at low levels; there are no data on effects of interferon beta-1a on milk production
Therefore, developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed infant from drug or from underlying maternal condition
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Recombinant interferon; antiviral, antiproliferative, immunoregulatory protein; alters response to surface antigen and may enhance immune cell activities
Pharmacokinetics
Onset of action: 12 hr (Avonex)
Duration: 4 days (Avonex)
Peak plasma time: 7.8-9.8 hr (IM); 16 hr (SC)
Concentration: 5.1±1.7 IU/mL (SC)
AUC: 294±81 IU.hr/mL (SC)
Half-Life: 8.6-10 hr (IM); 69±37 hr (SC)
Clearance: 33-55 L/hr (SC)
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| Avonex intramuscular - | 30 mcg/0.5 mL device |  | |
| Avonex intramuscular - | 30 mcg/0.5 mL syringe |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
interferon beta-1a intramuscular
INTERFERON BETA-1A PREFILLED SYRINGE - INJECTION
(IN-ter-FEER-on BAY-ta-wun-ay)
COMMON BRAND NAME(S): Avonex
USES: This medication is used to treat multiple sclerosis (MS). Interferon is not a cure for MS, but it may help to slow disease worsening and decrease flare-ups of symptoms (such as balance problems, numbness, or weakness).
HOW TO USE: Read the Medication Guide and Instructions for Use provided by your pharmacist before you start using interferon beta-1A and each time you get a refill. If you have any questions, ask your doctor or pharmacist.If you are using this medication at home, learn all preparation and usage instructions from your health care professional. Before using, check this product visually for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard medical supplies safely.To increase comfort, remove this medication from the refrigerator and let it warm to room temperature for about 30 minutes before injecting. Do not warm up this medication in any other way such as heating in the microwave or placing in hot water.Inject this medication into a muscle as directed by your doctor, usually once a week. It is best to use this medication near bedtime to reduce side effects.Before injecting each dose, clean the injection site with rubbing alcohol. Change the injection site each time to lessen injury. Do not inject into skin that is red, sore, scarred, or infected. If you are using the prefilled syringe, inject this medication into the thigh or upper arm as directed by your doctor. If you are using the autoinjector, inject into the upper outer thigh as directed. Tell your doctor of any skin reactions that do not go away after a few days.The dosage is based on your medical condition and response to treatment. To reduce your risk of side effects, your doctor may direct you to start this medication at a low dose and gradually increase your dose. Follow your doctor's instructions carefully. Use this medication regularly to get the most benefit from it. To help you remember, use it on the same day each week.Tell your doctor if your condition gets worse.
SIDE EFFECTS: Pain, swelling, or redness at the injection site may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Most people have flu-like symptoms such as headache, tiredness, fever, chills, and muscle aches when they first start this medication. These symptoms usually last about 1 day after the injection and improve or go away after a few months of continued use. You can lessen these side effects by injecting this medicine at bedtime and by using fever reducers/pain relievers such as acetaminophen or ibuprofen before each dose. Ask your doctor or pharmacist for more information.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as new or worsening depression, thoughts of suicide, psychosis), feeling too hot or cold (more than others around you), blue fingers/toes, easy bleeding/bruising, pus or change in skin color at the injection site, joint pain/swelling, signs of kidney problems (such as a change in the amount of urine), signs of liver problems (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine), new or worsening symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain).Get medical help right away if you have any very serious side effects, including: seizures.This medication may lower your ability to fight infections. This may make you more likely to get a serious (rarely fatal) infection or make any infection you have worse. Tell your doctor right away if you have any signs of infections (such as sore throat that doesn't go away, fever, chills, cough).A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before using interferon, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients (such as natural rubber/latex), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: bleeding/blood problems, heart problems (such as heart failure, angina, fast/irregular heartbeat), liver disease, mental/mood disorders (such as depression, psychosis, suicidal thoughts), seizure disorder, thyroid disease.Interferon can make you more likely to get infections or may worsen any current infections. Avoid contact with people who have infections that may spread to others (such as chickenpox, measles, flu). Consult your doctor if you have been exposed to an infection or for more details.Do not have immunizations/vaccinations without the consent of your doctor. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.This medication passes into breast milk in small amounts, but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: Do not share this medication with others.Lab and/or medical tests (such as complete blood count, liver/thyroid function) should be done while you are using this medication. Keep all medical and lab appointments.
MISSED DOSE: If you miss a dose, use it as soon as you remember. Do not use this medication 2 days in a row. Do not double the dose to catch up. Follow your usual schedule the next week.
STORAGE: Store in the refrigerator away from light. Do not freeze. This medication may also be stored at room temperature for up to 7 days. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised August 2021. Copyright(c) 2021 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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Adding plans allows you to:
- View the formulary and any restrictions for each plan.
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- Compare formulary status to other drugs in the same class.
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