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interferon beta-1a (in-ter-feer-on bay-ta won-aye)

Avonex, Rebif


Therapeutic: anti–multiple sclerosis agents, immune modifiers

Pharmacologic: interferons


Relapsing forms of multiple sclerosis.


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.

Adverse Reactions/Side Effects

CNS: SEIZURES, depression, dizziness, fatigue, headache, drowsiness, incoordination, rigors, suicidal ideation. EENT: sinusitis, vision abnormalities. Resp: upper respiratory tract infection. CV: chest pain, heart failure. GI: abdominal pain, nausea, autoimmune hepatitis, dry mouth, elevated liver function studies. GU: urinary tract infection, urinary incontinence, polyuria. Derm: alopecia, rash. Endo: hyperthyroidism, hypothyroidism, spontaneous abortion. Hemat: neutropenia, anemia, thrombocytopenia. Local: injection-site reactions, injection site necrosis. MS: myalgia, arthralgia, back pain, muscle spasm. Misc: allergic reactions, including anaphylaxis, chills, fever, flu-like symptoms, pain.


Examination and Evaluation

  • Be alert for new seizures or increased seizure activity, especially at the onset of drug treatment. Document the number, duration, and severity of seizures, and report these findings to the physician immediately.

  • Monitor signs of allergic reactions and anaphylaxis, including pulmonary symptoms (tightness in the throat and chest, wheezing, cough, dyspnea), or skin reactions (rash, pruritus, urticaria, dermatitis). Notify physician or nursing staff immediately if these reactions occur.

  • Periodically assess balance, coordination, spasticity, and other aspects of neuromuscular function to help document this drug's effectiveness in reducing MS exacerbations.

  • Monitor personality changes, including depression and increased thoughts of suicide. Notify physician if these changes become problematic.

  • Monitor any chest pain or signs of heart failure, including dyspnea, rales/crackles, peripheral edema, jugular venous distention, and exercise intolerance. Report these signs to the physician.

  • Assess any joint, back, or muscle pain and spasm to rule out musculoskeletal pathology; that is, try to determine if pain is drug induced rather than caused by anatomic or biomechanical problems.

  • Monitor and report any increase or decrease in metabolism that might indicate thyroid disorders. Signs of hyperthyroidism include tachycardia, nervousness, heat intolerance, weight loss, and muscle wasting. Hypothyroidism is typically indicated by bradycardia, lethargy, cold intolerance, weight gain, and muscle weakness.

  • Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.

  • Assess injection site for pain, swelling, and irritation. Report prolonged or excessive injection site reactions to the physician.


  • Design and implement coordination, balance, and other therapeutic exercises to maintain function and complement drug effects in patients ...

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