Rebif Adverse Reactions

General Description: The highest incidence of adverse reactions associated with Rebif therapy is related to flu-like syndrome. Flu-like symptoms tend to be most prominent at the initiation of therapy and decrease in frequency with continued treatment. Approximately 70% of patients treated with Rebif can expect to experience the typical interferon flu-like syndrome within the first 6 months after starting treatment. Approximately 30% of patients will also experience reactions at the injection site, predominantly mild inflammation or erythema. Asymptomatic increases in laboratory parameters of hepatic function and decreases in WBC are also common.
The majority of adverse reactions observed with interferon-β_1a are usually mild and reversible, and respond well to dose reductions.
In case of severe or persistent undesirable effects, the dose of Rebif may be temporarily lowered or interrupted at the discretion of the physician.
Adverse Reactions by Frequency: The adverse reactions reported as follows are classified according to frequency of occurrence as follows: Very common (≥1/10); common (≥1/100 to <1/10); uncommon (≥1/1000 to <1/100); rare (≥1/10,000 to <1/1000); very rare (<1/10,000). Within each frequency grouping, adverse reactions are presented in order of decreasing severity.
Infections and Infestations: Uncommon: Injection site abscess. Not Known*: Injection site infections, including cellulitis.
Blood and Lymphatic System Disorders: Very Common: Neutropenia, lymphopenia, leucopenia, thrombocytopenia, anaemia. Not Known*: Thrombotic thrombocytopenic purpura/haemolytic uremic syndrome.
Immune System Disorders: Not Known*: Anaphylactic reactions.
Endocrine Disorders: Uncommon: Thyroid dysfunction most often presenting as hypothyroidism or hyperthyroidism.
Psychiatric Disorders: Common: Depression, insomnia. Not Known*: Suicide attempt.
Nervous System Disorders: Very Common: Headache. Not Known*: Seizures, transient neurological symptoms (ie, hypoesthesia, muscle spasm, paraesthesia, difficulty in walking, musculoskeletal stiffness) that may mimic multiple sclerosis exacerbations.
Eye Disorders: Not Known*: Retinal vascular disorders (eg, retinopathy, cotton wool spots and obstruction of retinal artery or vein).
Vascular Disorders: Not Known*: Thromboembolic events.
Respiratory, Thoracic and Mediastinal Disorders: Not Known*: Dyspnoea.
Gastrointestinal Disorders: Common: Diarrhoea, vomiting, nausea.
Hepatobiliary Disorders: Not Known*: Hepatic failure, hepatitis with or without icterus.
Skin and Subcutaneous Tissue Disorders: Common: Pruritus, rash, erythematous rash, maculopapular rash. Not Known*: Angioedema, urticaria, erythema multiforme, erythema multiforme-like skin reactions, Stevens-Johnson syndrome, alopecia.
Musculoskeletal and Connective Tissue Disorders: Common: Myalgia, arthralgia.
General Disorders and Administration Site Conditions: Very Common: Injection site inflammation, injection site reaction, influenza-like symptoms. Common: Injection site pain, fatigue, rigors, fever. Uncommon: Injection site necrosis, injection site mass.
Investigations: Very Common: Increased asymptomatic transaminase. Common: Severe elevations of transaminase.
*Adverse reactions identified during post-marketing surveillance (frequency not known).
Information Characterizing Individual Serious and/or Frequently Occurring Adverse Reactions: Rebif, like other interferons β, has a potential for causing severe liver injury. The mechanism for the rare symptomatic hepatic dysfunction is not known. The majority of the cases of severe liver injury occurred within the first 6 months of treatment. No specific risk factors have been identified. Treatment with Rebif should be stopped if icterus or other clinical symptoms of liver dysfunction appear (see Precautions).
Adverse Reactions that Apply to the Pharmacological Class: The administration of interferons has been associated with anorexia, dizziness, anxiety, arrythmias, vasodilation and palpitation, menorrhagia and metrorrhagia.
An increased formation of autoantibodies may occur during treatment with interferon-β.