interferon beta-1a

Contraindicated in:

Hypersensitivity to natural or recombinant interferon beta.

Use Cautiously in:

History of suicide attempt or depression;
History of seizures;
Cardiovascular disease;
Liver disease;
History of alcohol abuse;
OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk;
Lactation: Use while breastfeeding only if potential maternal benefit justifies potential risk to infant;
Rep: Women of reproductive potential;
Pedi: Safety and effectiveness not established in children.

Adv. Reactions/Side Effects ⬆ ⬇

CV: chest pain, heart failure

Derm: alopecia, ERYTHEMA MULTIFORME, ↑sweating, rash, STEVENS-JOHNSON SYNDROME

EENT: sinusitis, vision abnormalities

Endo: hyperthyroidism, hypothyroidism

GI: abdominal pain, nausea, autoimmune hepatitis, dry mouth, ↑liver enzymes

GU: urinary tract infection, polyuria, spontaneous abortion, urinary incontinence

Hemat: neutropenia, anemia, HEMOLYTIC UREMIC SYNDROME, thrombocytopenia, THROMBOTIC THROMBOCYTOPENIC PURPURA

Local: injection-site reactions, injection site necrosis

MS: myalgia, pain, arthralgia, back pain, muscle spasm

Neuro: depression, dizziness, fatigue, headache, drowsiness, incoordination, rigors, SEIZURES, suicidal ideation

Resp: PULMONARY ARTERIAL HYPERTENSION, upper respiratory tract infection

Misc: chills, fever, flu-like symptoms, HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS)

Interactions ⬆ ⬇

Drug-drug:

↑myelosuppression may occur with other myelosuppressives including antineoplastics.
Concurrent use of hepatotoxic agents may ↑ the risk of hepatotoxicity (↑ liver enzymes).

Drug-Natural Products:

Avoid concomitant use with immmunomodulating natural products such as astragalus, echinacea, and melatonin.

Availability ⬆ ⬇

Avonex

Rebif

Solution for injection (prefilled syringes and prefilled pens): 30 mcg/0.5 mL
Solution for injection (prefilled 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

Route/Dosage ⬆ ⬇

Avonex

IM (Adults ): 30 mcg once weekly.

Rebif

SC (Adults ): Target dose of 22 mcg 3 times/wk—Start with 4.4 mcg 3 times/wk for 2 wk, then ↑ to 11 mcg 3 times/wk for 2 wk, then ↑ 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 ↑ to 22 mcg 3 times/wk for 2 wk, then ↑ to maintenance dose of 44 mcg 3 times/wk.

US Brand Names ⬆ ⬇

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.

Classifications ⬆ ⬇

Therapeutic Classification: anti-multiple sclerosis agents, immune modifiers

Pharmacologic Classification: interferons

Pharmacokinetics ⬆ ⬇

Absorption: 50% absorbed following SUBQ administration.

Distribution: Unknown.

Metabolism/Excretion: Unknown.

Half-Life: 69 hr (SUBQ), 10 hr (IM).

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
IM	unknown	3–15 hr	unknown
SUBQ	unknown	16 hr	unknown

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.
- May cause injection site reactions, including injection site necrosis. Periodically assess patient understanding and use of aseptic self-injection techniques, particularly if injection site necrosis has occurred. Discontinuation of therapy following a single site of necrosis is based on the extent of necrosis. For patients who continue therapy after injection site necrosis has occurred, avoid administration into affected area until fully healed. If multiple lesions occur, change injection site or discontinue therapy until healing occurs.
- 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. Advise patients that starting with a lower dose than 30 mcg and increasing dose over wks reduces incidence and severity of flu-like symptoms.
- Advise patient and family to notify health care professional immediately if signs and symptoms of depression, suicide, hallucinations, liver problems (nausea, yellowing of skin or white part of eye, loss of appetite, bleeding more easily than usual, tiredness, dark colored urine and pale stools, confusion, sleepiness), shortness of breath, difficulty breathing, fatigue, or allergic reactions (itching; swelling of face, eyes, lips, tongue or throat; trouble breathing; anxiousness; feeling faint; rash; hives; sores in mouth, skin blisters and peels) occur.
- Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected, or if breastfeeding.

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Indications ⬇

Contraind./Precautions ⬆ ⬇