Interferon Alfa-2b / Ribavirin Side Effects

Applies to interferon alfa-2b/ribavirin: capsule, solution, tablet.

Precautions

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

This medicine may cause some people to become unusually tired or dizzy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or if you are not alert.

This medicine may make you feel very sad, depressed, or very angry. Call your doctor if you feel you cannot cope or you feel like you want to hurt yourself or someone else.

Interferon alfa-2b commonly causes a flu-like reaction, with aching muscles, fever and chills, and headache. To prevent problems from your temperature going too high, your doctor may ask you to take medicine for pain and fever such as acetaminophen (e.g., Anacin 3, Tylenol) before each dose of interferon alfa-2b. You may also need to take it after a dose to bring your temperature down. Follow your doctor's instructions carefully about taking your temperature, and how much and when to take the medicine such as acetaminophen.

Women of childbearing potential should use two reliable forms of effective contraception.

Alpha interferon can lower the number of white blood cells in your blood temporarily, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

• If you can, avoid being close to people with infections. Check with your doctor immediatelyif you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or have painful or difficult urination.
• Check with your doctor immediately if you notice any unusual bleeding or bruising; black, tarry stools; blood in urine or stools; or pinpoint red spots on your skin.
• Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
• Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
• Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
• Avoid contact sports or other situations where bruising or injury could occur.

Serious side effects

Along with its needed effects, interferon alfa-2b / ribavirin may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur while taking interferon alfa-2b / ribavirin:

Other side effects

Some side effects of interferon alfa-2b / ribavirin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to interferon alfa-2b / ribavirin: oral and injectable kit.

General adverse events

Interferon alfa-2b-ribavirin therapy was discontinued in 19% and 6% of previously untreated and relapse patients, respectively, during clinical trials. In comparison, 13% of previously untreated patients and 3% of relapse patients discontinued therapy in the interferon arms.

Alpha interferons, including interferon alfa-2b, have caused or aggravated fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. In many but not all cases these disorders resolved after stopping interferon alfa-2b.^[Ref]

Hematologic

Hemolytic anemia is the primary toxicity of ribavirin therapy. Hemoglobin levels generally declined within the first 1 to 2 weeks of ribavirin therapy. Cardiac and pulmonary events associated with anemia have been reported in about 10% of patients.

The mean maximum decrease from baseline hemoglobin levels observed in US and international studies ranged from 2.6 g/dL to 3.1 g/dL. Hemoglobin values returned to pretreatment levels within 4 to 8 weeks of cessation of therapy in most patients. Neutrophil and platelet values returned to pretreatment levels within 4 weeks after treatment discontinuation.^[Ref]

Hematologic side effects have included decreased hemoglobin (9.5 to 10.9 g/dL: up to 32%; 8 to 9.4 g/dL: up to 5%), leukocytes [2 to 2.9 x 10(9)/L: up to 45%; 1.5 to 1.9 x 10(9)/L: up to 9%; 1 to 1.4 x 10(9)/L: up to 2%], neutrophils [1 to 1.49 x 10(9)/L: up to 42%; 0.75 to 0.99 x 10(9)/L: up to 16%; 0.5 to 0.74 x 10(9)/L: up to 14%; less than 0.5 x 10(9)/L: up to 11%], and platelets [70 to 99 x 10(9)/L: up to 11%; 50 to 69 x 10(9)/L: up to 2%; less than 30 x 10(9)/L: up to 1%]. Bone marrow function suppression, which may result in severe cytopenias, has been reported with interferon alfa-2b therapy. Hemolytic anemia (hemoglobin less than 10 g/dL) was observed in approximately 10% of patients on combination therapy in clinical trials. Aplastic anemia has been rarely reported with interferon alfa-2b-ribavirin therapy.^[Ref]

Respiratory

Respiratory side effects have included dyspnea (up to 19%) and sinusitis (up to 12%). Pulmonary symptoms (including dyspnea, pulmonary infiltrates, pneumonitis, pulmonary hypertension, pneumonia, and fatal pneumonia), sarcoidosis, and exacerbation of sarcoidosis have been reported.^[Ref]

Cardiac and pulmonary events associated with anemia have been reported in about 10% of patients.^[Ref]

Cardiovascular

Cardiovascular side effects have included deterioration of cardiac function and/or exacerbation of the symptoms of coronary disease due to the anemia associated with interferon alfa-2b-ribavirin therapy.^[Ref]

Cardiac and pulmonary events associated with anemia have been reported in about 10% of patients.^[Ref]

Psychiatric

Psychiatric side effects have included insomnia (up to 39%), depression (up to 36%), irritability (up to 32%), impaired concentration (up to 14%), emotional lability (up to 12%), and nervousness (up to 5%). Suicidal behavior (including ideation, attempts, and suicides) has been reported in 1% of patients. Severe psychiatric side effects, including depression, psychoses, aggressive behavior, hallucinations, violent behavior (suicidal ideation, suicidal attempts, suicides), and rare cases of homicidal ideation, have been reported in patients with and without previous psychiatric disorder.^[Ref]

Nervous system

Nervous system side effects have included headache (up to 66%), dizziness (up to 26%), and taste perversion (up to 8%). Hearing disorders (including tinnitus and hearing loss) and vertigo have been reported in postmarketing studies.^[Ref]

Gastrointestinal

Gastrointestinal side effects have included nausea (up to 47%), anorexia (up to 27%), dyspepsia (up to 16%), and vomiting (up to 12%). Pancreatitis, including fatal and nonfatal, has been observed.^[Ref]

Musculoskeletal

Musculoskeletal side effects have included myalgia (up to 64%), arthralgia (up to 33%), and musculoskeletal pain (up to 28%).^[Ref]

Ocular

Ocular side effects induced or aggravated by alpha interferon therapy have included decrease or loss of vision, retinopathy including macular edema, retinal artery or vein thrombosis, retinal hemorrhages and cotton wool spots, optic neuritis, papilledema, and serous retinal detachment.^[Ref]

Hypersensitivity

Hypersensitivity side effects have included acute serious hypersensitivity reactions (e.g., urticaria, angioedema, bronchoconstriction, and anaphylaxis) in patients treated with interferon alfa-2b.^[Ref]

Dermatologic

Dermatologic side effects have included alopecia (up to 32%), rash (up to 28%), and pruritus (up to 21%). Exacerbation of preexisting psoriasis has been reported. Transient rashes have been reported in some patients following interferon alfa-2b injection.^[Ref]

Endocrine

Endocrine side effects have included thyroid abnormalities, including hypothyroidism and hyperthyroidism. Thyroiditis has been reported.^[Ref]

A case report of hyperthyroidism, manifested in the form of thyroiditis, in a 28-year-old woman responding well to interferon alfa-2b-ribavirin therapy, suggested that temporary interferon alfa-2b dose reduction and symptomatic treatment may be all that is needed in destructive thyroiditis.^[Ref]

Local

Local side effects have included injection site inflammation (up to 13%) and injection site reaction (up to 8%).^[Ref]

Other

Other side effects have included fatigue (up to 70%), rigors (up to 43%), fever (up to 41%), influenza-like symptoms (up to 18%), asthenia (up to 10%), and chest pain (up to 9%). Increases in both bilirubin and uric acid, associated with hemolysis, have been reported in clinical trials. Elevated total bilirubin (1.5 to 3 mg/dL: up to 32%; 3.1 to 6 mg/dL: up to 3%; 6.1 to 12 mg/dL: up to 0.4%) has been reported.^[Ref]

Most cases of increased bilirubin and uric acid were moderate biochemical changes, reversed within 4 weeks after treatment discontinuation, and were not associated with hepatic dysfunction or clinical morbidity.^[Ref]

Immunologic

Immunologic side effects have included exacerbation of autoimmune disease in patients receiving interferon alfa-2b.

Metabolic

Metabolic side effects have included elevated triglycerides, hyperglycemia, new onset diabetes mellitus, exacerbation of preexisting diabetes mellitus, and diabetic ketoacidosis.^[Ref]

Diabetic ketoacidosis was reported in a 53-year-old white female after week 24 of treatment, who had in the first 12 weeks of treatment normal random blood glucose limits (less than 110 mg/dL), and required insulin. Interferon alfa-2b-ribavirin was stopped.^[Ref]

See also:

Further information

Interferon alfa-2b/ribavirin side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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