Endocrine Disorders
Infrequently, patients receiving INTRON A therapy developed thyroid abnormalities, either hypothyroid or hyperthyroid. The mechanism by which INTRON A may alter thyroid status is unknown. Patients with preexisting thyroid abnormalities whose thyroid function cannot be maintained in the normal range by medication should not be treated with INTRON A. Prior to initiation of INTRON A therapy, serum TSH should be eva luated. Patients developing symptoms consistent with possible thyroid dysfunction during the course of INTRON A therapy should have their thyroid function eva luated and appropriate treatment instituted. Therapy should be discontinued for patients developing thyroid abnormalities during treatment whose thyroid function cannot be normalized by medication. Discontinuation of INTRON A therapy has not always reversed thyroid dysfunction occurring during treatment. Diabetes mellitus has been observed in patients treated with alpha interferons. Patients with these conditions who cannot be effectively treated by medication should not begin INTRON A therapy. Patients who develop these conditions during treatment and cannot be controlled with medication should not continue INTRON A therapy.

Gastrointestinal Disorders
Hepatotoxicity, including fatality, has been observed in interferon alpha-treated patients, including those treated with INTRON A. Any patient developing liver function abnormalities during treatment should be monitored closely and if appropriate, treatment should be discontinued.

Pulmonary Disorders
Dyspnea, pulmonary infiltrates, pneumonia, bronchiolitis obliterans, interstitial pneumonitis, pulmonary hypertension, and sarcoidosis, some resulting in respiratory failure and/or patient deaths, may be induced or aggravated by INTRON A or other alpha interferons. Recurrence of respiratory failure has been observed with interferon rechallenge. The etiologic explanation for these pulmonary findings has yet to be established. Any patient developing fever, cough, dyspnea, or other respiratory symptoms should have a chest X-ray taken. If the chest X-ray shows pulmonary infiltrates or there is evidence of pulmonary function impairment, the patient should be closely monitored, and, if appropriate, interferon alpha treatment should be discontinued. While this has been reported more often in patients with chronic hepatitis C treated with interferon alpha, it has also been reported in patients with oncologic diseases treated with interferon alpha.

Autoimmune Disorders
Rare cases of autoimmune diseases including thrombocytopenia, vasculitis, Raynaud's phenomenon, rheumatoid arthritis, lupus erythematosus, and rhabdomyolysis have been observed in patients treated with alpha interferons, including patients treated with INTRON A. In very rare cases the event resulted in fatality. The mechanism by which these events developed and their relationship to interferon alpha therapy is not clear. Any patient developing an autoimmune disorder during treatment should be closely monitored and, if appropriate, treatment should be discontinued.

Human Albumin
The powder formulations of this product contain albumin, a derivative of human blood. Based on effective donor screening and product manufacturing processes, it carries an extremely remote risk