Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

interferon beta 1a (Rx)Brand and Other Names:Avonex, Rebif, more...Rebif Rebidose, AVOSTARTGRIP

 
 
 

Dosing & Uses

AdultPediatricGeriatric

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
more...

Multiple Sclerosis

Indicated for the treatment of relapsing forms of multiple sclerosis 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
more...

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

Next

Interactions

Interaction Checker

interferon beta 1a and

No Results

     
     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

            Sort by :  
             activity indicator 
            Previous
            Next

            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)

            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

            Previous
            Next

            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

            Previous
            Next

            Pregnancy & Lactation

            Pregnancy Category: C

            Lactation: unknown; use caution

            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.

            more...
            Previous
            Next

            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)

            Previous
            Next

            Images

            Previous
            Next

            Formulary

            FormularyPatient Discounts

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
            Add or Remove Plans
            Plans for
            Select State:
            Non-Medicare PlansMedicare Plans

            Select a box to add or remove a plan.

            Select a class to view formulary status for similar drugs

            Additional Offers
            Email to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Email Forms to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Previous
             
             
             
            All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.