Interferons, Alpha (Systemic)

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Because this medicine is used for many different conditions and in many different doses, the actual frequency of side effects may vary. In general, side effects are less common with low doses than with high doses. Also, when alpha interferon is used for genital warts, very little of it gets into the rest of the body, so side effects are generally less common than in other conditions.

Check with your doctor as soon as possible if any of the following side effects occur:

Less common

Confusion; mental depression; nervousness; numbness or tingling of fingers, toes, and face; trouble in sleeping; trouble in thinking or concentrating

Rare

Black, tarry stools; blood in urine or stools; chest pain; cough or hoarseness accompanied by fever or chills; fever or chills (beginning after 3 weeks of treatment); headache; irregular heartbeat; lower back or side pain accompanied by fever or chills; muscle pain; numbness or tingling in the legs; pain, swelling or redness in the joints; painful or difficult urination accompanied by fever or chills; pinpoint red spots on skin; trouble speaking; unusual bleeding or bruising

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

More common

Aching muscles; change in taste or metallic taste; fever and chills (should lessen after the first 1 or 2 weeks of treatment); general feeling of discomfort or illness; headache; loss of appetite; nausea and vomiting; skin rash; unusual tiredness

Less common or rare

Back pain; blurred vision; diarrhea; dizziness; dryness of mouth; dry skin or itching; increased sweating; joint pain; leg cramps; sores in mouth and on lips; weight loss

Alpha interferon may cause a temporary loss of some hair. After treatment has ended, normal hair growth should return.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.