interferon beta-1a(redirected from Extavia)
Pharmacologic class: Biological response modifier
Therapeutic class: Antiviral, immunoregulator
Pregnancy risk category C
Binds and competes with specific receptors on cell surface, inducing various interferon-induced gene products. Also inhibits proliferation of T cells.
Lyophilized powder for injection (beta-1a): 22 mcg (6 million international units; Rebif), 33 mcg (6.6 million international units; Avonex), 44 mcg (12 million international units; Rebif)
Lyophilized powder for injection (beta-1b): 0.3 mg in glass, single-use, 3-ml vial
Powder for injection (beta-1b): 0.3 mg (9.6 million international units; Betaseron)
Prefilled syringes (beta-1a): 30 mcg/0.5 ml (Avonex)
Indications and dosages
➣ To reduce frequency of exacerbations in relapsing-remitting multiple sclerosis
Adults ages 18 and older: 8.8 mcg Rebif subcutaneously three times weekly, increased over a 4-week period to 44 mcg three times weekly. Or 30 mcg Avonex I.M. once a week. Or 8 million international units (0.25 mg) Betaseron subcutaneously every other day. Or initially, 0.0625 mg (0.25 ml) (Extavia) subcutaneously every other day, increased over 6 weeks to 0.25 mg (1 ml) every other day.
• Hypersensitivity to drug, its components, or albumin
Use cautiously in:
• cardiac disease, seizure disorders, mental disorders, depression, suicidal tendencies
• women of childbearing age
• pregnant or breastfeeding patients
• children ages 18 and younger.
• Reconstitute Avonex (I.M. injection) and Rebif (subcutaneous injection) using diluent provided, according to instructions provided.
• Reconstitute Betaseron (subcutaneous injection) using 1.2 ml of diluent supplied by manufacturer, to yield a concentration of 0.25 mg/ml. Swirl gently to mix; don't shake. Use reconstituted drug within 3 hours; discard unused portion.
• Reconstitute Extavia (subcutaneous injection) by attaching prefilled, single-use syringe containing 1.2 ml of diluent supplied by manufacturer to vial using vial adapter. Slowly inject 1.2 ml of diluent into vial to yield a concentration of 0.25 mg/ml. Swirl gently to mix; don't shake. Use reconstituted drug within 3 hours; discard unused portion.
CNS: dizziness, confusion, rigors, paresthesia, lethargy, depression, difficulty thinking or concentrating, insomnia, anxiety, fatigue, amnesia, nervousness, drowsiness, asthenia, malaise, suicidal ideation
CV: chest pain, hypertension, palpitations, arrhythmias
EENT: visual disturbances, stye, hearing disorders, nasal congestion, sinusitis, rhinitis, pharyngitis
GI: nausea, vomiting, diarrhea, constipation, abdominal pain, dyspepsia, flatulence, eructation, stomatitis, dry mouth, intestinal obstruction
GU: gynecomastia, breast pain, early or delayed menses, menstrual bleeding or spotting, shortened duration of menstrual flow, menorrhagia
Hematologic: anemia, neutropenia, leukopenia, thrombocytopenia
Musculoskeletal: joint pain, back pain, myalgia, myasthenia
Respiratory: cough, dyspnea
Skin: rash, dry skin, pruritus, flushing, alopecia, dermatitis, diaphoresis
Other: gingivitis, flulike symptoms, weight loss, edema, candidiasis, lymphadenopathy, inflammation, pain
Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, blood urea nitrogen, creatinine, glucose, lactate dehydrogenase, neutralizing antibodies, phosphorus, uric acid: increased values
Hemoglobin, neutrophils, white blood cells: decreased values
☞ Before therapy and monthly during therapy, assess CBC with white cell differential, glucose and electrolyte levels, and liver and kidney function tests.
• Assess fluid intake and output. Keep patient well hydrated.
• Watch for GI upset. Provide small, frequent meals to minimize nausea and vomiting.
☞ Monitor for mental status changes, depression, and suicidal ideation.
• Evaluate for bleeding and bruising.
• Institute infection-control measures. Monitor for infection symptoms.
• Teach patient or caregiver how to administer drug subcutaneously or I.M., rotate injection sites, and track dosing schedule and injection sites on calendar.
• Advise patient to avoid sources of potential infection, such as crowds and people with known infections.
• Tell patient to eat small, frequent meals to combat nausea, vomiting, and appetite loss.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, alertness, and vision.
☞ Tell patient to contact prescriber immediately if depression or suicidal ideation occurs.
• Inform female patient that drug is linked to fetal abnormalities. Advise her not to get pregnant during therapy, and to use barrier contraception. Tell her to consult prescriber before breastfeeding.
☞ Instruct patient to immediately report signs or symptoms of infection (such as fever, chills, sore throat, achiness), unusual bleeding or bruising, mental status changes, dizziness, palpitations, or chest pain.
• Tell patient he'll need regular follow-up examinations and blood tests to monitor drug effects.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the tests mentioned above.
interferon beta-1a(in-ter-feer-on bay-ta won-aye) ,
ClassificationTherapeutic: anti multiple sclerosis agents
Time/action profile (serum concentrations)
Adverse Reactions/Side Effects
Central nervous system
- seizures (life-threatening)
- depression (most frequent)
- dizziness (most frequent)
- fatigue (most frequent)
- headache (most frequent)
- suicidal ideation
Ear, Eye, Nose, Throat
- sinusitis (most frequent)
- vision abnormalities
- upper respiratory tract infection
- chest pain
- heart failure
- abdominal pain (most frequent)
- nausea (most frequent)
- autoimmune hepatitis
- dry mouth
- elevated liver function studies
- urinary tract infection (most frequent)
- urinary incontinence
- spontaneous abortion
- neutropenia (most frequent)
- injection-site reactions (most frequent)
- injection site necrosis
- myalgia (most frequent)
- back pain
- muscle spasm
- allergic reactions including anaphylaxis
- chills (most frequent)
- fever (most frequent)
- flu-like symptoms (most frequent)
- pain (most frequent)
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.
- 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 DiagnosesDeficient knowledge, related to medication regimen (Patient/Family Teaching)
- 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.
- 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.
- Decrease in the frequency of relapse (neurologic dysfunction) in patients with relapsing-remitting multiple sclerosis.