Interferon beta 1a

DEA Class;  Rx

Common Brand Names; Avonex, Rebif, Rebif Rebidose, AVOSTARTGRIP

• 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%)
• Abdominal pain (9%)
• Anemia (8%)
• Chest pain (6%)
• Aggravation of seizure disorders
• Autoimmune disorders: Drug-induced lupus erythematosus, autoimmune hepatitis
• Blood and lymphatic system disorders: Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), hemolytic anemia
• 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
• Injection site reactions including necrosis

Flu-like symptoms may occur

Efficacy in primary progressive MS not demonstrated conclusively; not recommended

Anaphylaxis reported as a rare complication of therapy; other allergic reactions have included dyspnea, orolingual edema, skin rash, and urticaria; discontinue therapy if anaphylaxis or other allergic reactions occur

Decreased peripheral blood counts in all cell lines, including rare pancytopenia and thrombocytopenia, reported from postmarketing experience in treated patients; in some cases, platelet counts were below10,000/microliter; some cases recurred with rechallenge; patients should be monitored for symptoms or signs of decreased blood counts

Cases of thrombotic microangiopathy (TMA), including thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, some fatal, have been reported; 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; manage as clinically indicated

Seizures have been temporally associated with use of beta interferons in clinical trials and postmarketing safety surveillance; not known whether the events were related to the effects of multiple sclerosis alone, the drug, or to a combination of both

Data from a large population-based cohort study, as well as other published studies over several decades, have not identified a drug-associated risk of major birth defects with use during early pregnancy

Limited published literature has described the presence of interferon beta-1a products in human milk at low levels; there are no data on effects of interferon beta-1a on milk production