Hazardous agent. Causes bone marrow suppression, including potentially severe cytopenias, and very rarely, aplastic anemia. Flu-like symptoms, including fever, are common. Gastrointestinal effects, such as hemorrhage, ulcerative and hemorrhagic/ischemic colitis observed. Transient liver abnormalities might occur when treating chronic hepatitis C. Acute hypersensitivity reactions reported (rarely) with alpha interferons. Hypertriglyceridemia, serious and severe infections (bacterial, viral and fungal), nephrotoxicity reported. Might cause severe psychiatric adverse events (e.g. depression, psychosis, mania, suicidal behavior/ideation) in patients with and without previous psychiatric symptoms (use with caution in seizure disorders, brain metastases, or compromised CNS function). Higher doses in the elderly or in malignancies other than hairy cell leukemia may result in severe obtundation. Ocular effects might occur (use caution in pre-existing ophthalmic disorders). Pancreatitis observed (occasionally fatal). Pulmonary effects might occur (use caution in history of pulmonary disease). Avoid use in history of autoimmune disorders. Use with caution in history of cardiovascular disease, or in diabetes mellitus (hyperglycemia reported). May cause or aggravate fatal or life-threatening infectious disorders. May cause or aggravate fatal or life-threatening ischemic disorders. Use with caution in renal impairment (CrCl <50 mL/minute). Thyroid disorders (hyper-/hypothyroidism) reported (use with caution in pre-existing thyroid disease). Injection solution contains benzyl alcohol, associated with «gasping syndrome» in neonates.