Avonex

interferon beta-1a

(in-ter-feer-on bay-ta won-aye) ,

Avonex

(trade name),

Rebif

(trade name)

Classification

Therapeutic: anti multiple sclerosis agents
Pharmacologic: interferons
Pregnancy Category: C

Indications

Relapsing forms of multiple sclerosis.

Action

Antiviral and immunoregulatory properties produced by interacting with specific receptor sites on cell surfaces may explain beneficial effects.
Produced by recombinant DNA technology.

Therapeutic effects

Reduce incidence of relapse (neurologic dysfunction) and slow physical disability.

Pharmacokinetics

Absorption: 50% absorbed following subcut administration.
Distribution: Unknown.
Metabolism and Excretion: Unknown.
Half-life: 69 hr (subcutaneous), 10 hr (IM).

Time/action profile (serum concentrations)

ROUTEONSETPEAKDURATION
IMunknown3–15 hrunknown
SCunknown16 hrunknown

Contraindications/Precautions

Contraindicated in: Hypersensitivity to natural or recombinant interferon beta or human albumin.
Use Cautiously in: Patients with a history of suicide attempt or depression; History of seizures; Cardiovascular disease; Liver disease; History of alcohol abuse; Patients with childbearing potential; Obstetric / Lactation / Pediatric: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

  • seizures (life-threatening)
  • depression (most frequent)
  • dizziness (most frequent)
  • fatigue (most frequent)
  • headache (most frequent)
  • drowsiness
  • incoordination
  • rigors
  • suicidal ideation

Ear, Eye, Nose, Throat

  • sinusitis (most frequent)
  • vision abnormalities

Respiratory

  • upper respiratory tract infection

Cardiovascular

  • chest pain
  • heart failure

Gastrointestinal

  • abdominal pain (most frequent)
  • nausea (most frequent)
  • autoimmune hepatitis
  • dry mouth
  • elevated liver function studies

Genitourinary

  • urinary tract infection (most frequent)
  • urinary incontinence
  • polyuria

Dermatologic

  • alopecia
  • rash

Endocrinologic

  • hyperthyroidism
  • hypothyroidism
  • spontaneous abortion

Hematologic

  • neutropenia (most frequent)
  • anemia
  • thrombocytopenia

Local

  • injection-site reactions (most frequent)
  • injection site necrosis

Musculoskeletal

  • myalgia (most frequent)
  • arthralgia
  • back pain
  • muscle spasm

Miscellaneous

  • allergic reactions including anaphylaxis
  • chills (most frequent)
  • fever (most frequent)
  • flu-like symptoms (most frequent)
  • pain (most frequent)

Interactions

Drug-Drug interaction

↑ myelosuppression may occur with other myelosuppressives including antineoplastics.Concurrent use of hepatotoxic agents may ↑ the risk of hepatotoxicity (↑ liver enzymes). Avoid concommitant use with immmunomodulating natural products such as astragalus, echinacea, and melatonin.

Route/Dosage

Avonex
Intramuscular (Adults) 30 mcg once weekly.
Rebif
Subcutaneous (Adults) Target dose of 22 mcg 3 times/wk–Start with 4.4 mcg 3 times/wk for 2 wk, then increase to 11 mcg 3 times/wk for 2 wk, then increase to maintenance dose of 22 mcg 3 times/wk;Target dose of 44 mcg 3 times/wk–Start with 8.8 mcg 3 times/wk for 2 wk, then increase to 22 mcg 3 times/wk for 2 wk, then increase to maintenance dose of 44 mcg 3 times/wk.

Availability

Avonex
Powder for injection: 30 mcg/vial
Prefilled syringes: 30 mcg/0.5 mL
Prefilled pens: 30 mcg/0.5 mL
Rebif
Pre-filled syringes: 22 mcg/0.5 mL, 44 mcg/0.5 mL, titration pack of 6 syringes prefilled with 8.8 mcg/0.2 mL and 6 syringes prefilled with 22 mcg/0.5 mL

Nursing implications

Nursing assessment

  • Assess frequency of exacerbations of symptoms of multiple sclerosis periodically during therapy.
  • Monitor patient for signs of depression during therapy. If depression occurs, notify.health care professional immediately.
  • Lab Test Considerations: Monitor hemoglobin, WBC, platelets, and blood chemistries including liver function tests prior to and 1, 3, and 6 mo after initiation of therapy. Therapy may be temporarily discontinued if the absolute neutrophil count is < 750/mm3, if AST or ALT exceeds 10 times the upper limit of normal, or if serum bilirubin exceeds 5 times the upper limit of normal. Once the absolute neutrophil count is > 750/mm3 or the hepatic enzymes have returned to normal, therapy can be restarted at 50% of the original dose. Thyroid function tests should also be monitored every 6 mo, especially in those patients with a history of thyroid abnormalities.

Potential Nursing Diagnoses

Deficient knowledge, related to medication regimen (Patient/Family Teaching)

Implementation

  • Do not confuse products. Interferon beta-1a and interferon beta-1b are not interchangeable.
  • Avonex:Reconstitute with 1.1 mL of diluent and swirl gently to dissolve. Do not shake the vial. Inject into the thigh or upper arm. Keep reconstituted solution in refrigerator; inject within 6 hr of reconstitution.
    • Rebif:Administer subcutaneously via pre-filled, single-use syringe at the same time (preferably the late afternoon or evening) on the same days (Monday, Wednesday, Friday) at least 48 hr apart each wk. Rotate sites with each injection to minimize risk of injection site reactions. Discard unused portions. Store in refrigerator.

Patient/Family Teaching

  • Home Care Issues: Instruct patient in correct technique for injection and care and disposal of equipment. Caution patient not to reuse needles or syringes and provide patient with a puncture-resistant container for disposal.
    • Instruct patient to take medication as directed; do not change dose or schedule without consulting health care professional. Patients should receive a medication guide with each product.
    • Inform patient that flu-like symptoms (fever, chills, myalgia, sweating, malaise) may occur during therapy. Acetaminophen may be used for relief of fever and myalgias.
    • Obstetric: Advise patient to notify health care professional if pregnancy is planned or suspected. May cause spontaneous abortion.

Evaluation/Desired Outcomes

  • Decrease in the frequency of relapse (neurologic dysfunction) in patients with relapsing-remitting multiple sclerosis.

Avonex

a trademark for an antiviral and immune system regulator (interferon beta-1a) useful for treating multiple sclerosis.

Avonex

A brand name for INTERFERON BETA-1a.
References in periodicals archive ?
The results mean that doctors can be confident that AVONEX 30 mcg IM once weekly is the right dose to use.
At the end of September, our landmark CHAMPS trial was published in the New England Journal of Medicine, showing that early treatment with AVONEX significantly reduced the rate at which individuals at high-risk for MS develop clinically definite multiple sclerosis (CDMS).
The FDA announced Friday that it will permit marketing of Avonex for the treatment of relapsing forms of multiple sclerosis.
BioTrends Research Group, one of the world's leading research and advisory firms for specialized biopharmaceutical issues, finds that while Biogen Idec's Avonex and Teva's Copaxone continue to capture almost one-half of multiple sclerosis (MS) patient share of first-line disease-modifying agent (DMA) therapy, Avonex share in 2012 (25 percent) has decreased significantly compared to the 2011 audit (29 percent).
Sales of the company's top seller, Avonex for multiple sclerosis, grew 1% to $580 million.
Richert continued, "the FDA is recommending that Tysabri be given only to people who have had an inadequate response to, or are unable to tolerate, the other MS therapies--Copaxone, Betaseron, Avonex, Rebif, or Novantrone.
DEVELOPED BY BIOGEN IDEC, AVONEX IS A ONCE-A-WEEK TREATMENT PROVEN TO SLOW THE PROGRESSION OF DISABILITY AND REDUCE THE FREQUENCY OF RELAPSES.
AVONEX remains the leader both in terms of number of patients and sales volume.
The FDA is close to giving final approval of Avonex.
This began with the approval of AVONEX and then TYSABRI, and continues today with the global regulatory submissions for oral dimethyl fumarate," said Alfred Sandrock, M.
It led directly to the development of three of today's disease-modifying drugs--the three that are based on interferon: Betaseron, Rebif, and Avonex.
A second Phase III trial looking at TYSABRI added to AVONEX (Interferon beta-1a), compared to AVONEX alone, showed 54% relative reduction in relapses over AVONEX alone.