When INTRON A products are administered in combination with ribavirin in patients with chronic hepatitis C, please also refer to ribavirin product information.

Patients should be cautioned not to change brands of interferon without medical consultation as a change in dosage may result.

Immunological Effects: A number of immune-mediated dermatological reactions associated with the use of alfa interferons have been reported ranging from erythema multiforme to more severe but very rare occurrences of Stevens-Johnson syndrome and toxic epidermal necrolysis.

Acute Hypersensitivity: Acute serious hypersensitivity reactions (e.g., urticaria, angioedema, bronchoconstriction, anaphylaxis) to INTRON A (interferon alfa-2b) have been observed rarely during INTRON A therapy. If such a reaction develops, the drug should be discontinued and appropriate medical therapy instituted immediately. Transient rashes do not necessitate interruption of treatment.

INTRON A Ready-to-use Solution (Albumin (human) free) and Solution for Injection (Albumin (human) free) Multi-dose Pen contain m-cresol as preservative; some patients may experience allergic reaction to this ingredient.

Hepatic Function: Hepatotoxicity, resulting in fatality has been observed rarely in INTRON A treated patients. Any patient developing liver function abnormalities or hepatopathy during treatment should be monitored closely and if appropriate, treatment should be discontinued.

Because of the fever and other “flu-like” symptoms associated with INTRON A administration, it should be used cautiously in patients with debilitating medical conditions, such as those with a history of cardiovascular disease (e.g., unstable angina, uncontrolled congestive heart failure), pulmonary disease (e.g., chronic obstructive pulmonary disease) or diabetes mellitus prone to ketoacidosis.

Fever: While fever may be associated with interferon therapy, other causes of persistent fever should be ruled out. Caution should also be observed in patients with coagulation disorders (e.g., thrombophlebitis, pulmonary embolism) or severe myelosuppression.

Cardiovascular: Chest pain, hypertension, cardiac arrhythmia, cardiac ischemia, and myocardial infarction have been reported in patients with and without a history of cardiac disorder or abnormality in association with the use of alpha interferon therapies including INTRON A. INTRON A should not be administered to patients with a history of severe pre-existing cardiac disease including unstable or uncontrolled cardiac disease in the previous 6 months. Patients with a history of cardiac disease (e.g., congestive heart failure, myocardial infarction and/or previous or current arrhythmic disorders) or with AIDS-related Kaposi's Sarcoma, who require INTRON A therapy, should be closely monitored (see Laboratory Tests). Those patients who have pre-existing cardiac abnormalities and/or are in advanced stages of cancer, should have ECGs taken prior to and during the course of treatment. Cardiac arrhythmias (primarily supraventricular) occurred rarely and appeared to be correlated with pre-existing conditions and prior therapy with cardiotoxic agents. These adverse experiences usually respond to conventional therapy but may require dose modification or discontinuation of INTRON A therapy.

Transient reversible cardiomyopathy was reported in approximately 2% of the AIDS-Related Kaposi's Sarcoma patients treated with INTRON A. Cardiomyopathy has also been reported in AIDS patients not receiving INTRON A therapy. Baseline chest X-rays are suggested and should be repeated if clinically indicated.

Hydration: Adequate hydration should be maintained in patients undergoing INTRON A therapy since hypotension related to fluid depletion has been seen in some patients during therapy and up to 2 days post-therapy. Fluid replacement may be necessary.

Psychiatric and Central Nervous System: If severe neuropsychiatric effects, particularly depression, are observed, INTRON A therapy should be discontinued. CNS effects manifested by depression, confusion and other alterations of mental status have been observed in some INTRON A-treated patients; suicidal ideation, attempted suicide and aggressive behavior have been observed rarely. These adverse effects have occurred in patients treated with recommended doses as well as in patients treated with higher INTRON A doses. More significant obtundation and coma, including cases of encephalopathy, have been observed in some patients, usually elderly, treated at higher doses. While these effects are generally reversible upon discontinuation of therapy, in a few patients full resolution took up to 3 weeks. Very rarely, seizures have occurred with high doses of INTRON A. If patients develop psychiatric problems or CNS problems, including clinical depression, it is recommended that the patients be carefully monitored due to the potential seriousness of these undesirable effects. Consideration should be given to discontinue therapy, if psychiatric intervention and/or dose reduction is unsuccessful in controlling psychiatric symptoms.