Interferon alfacon-1 warnings and precautions

# Warnings And Precautions
Treatment with INFERGEN and combination treatment with INFERGEN/ribavirin should be administered under the guidance of a qualified physician, and may lead to moderate-to-severe adverse reactions requiring dose reduction, temporary dose cessation, or discontinuation of further therapy.

## Use with ribavirin

### Pregnancy
ribavirin may cause birth defects and death of the unborn child. ribavirin therapy should not be started until a report of a negative pregnancy test has been obtained immediately prior to planned initiation of therapy. Patients should use at least two forms of contraception and have monthly pregnancy tests. Pregnancy should be avoided for at least six months after discontinuation of ribavirin  .

### Anemia
ribavirin caused hemolytic anemia in 30% of INFERGEN/ribavirin-treated subjects. Complete blood counts should be obtained pretreatment and at Week 2 and Week 4 of therapy or more frequently if clinically indicated. Anemia associated with ribavirin therapy may result in a worsening of cardiac disease. Decrease in dosage or discontinuation of ribavirin may be necessary .

## Neuropsychiatric Disorders
Severe psychiatric adverse reactions may manifest in patients receiving therapy with interferon alphas, including INFERGEN. Depression, suicidal ideation, suicide attempt, suicide, and homicidal ideation may occur. Other prominent psychiatric adverse reactions including psychosis, aggressive behavior, nervousness, anxiety, emotional lability, abnormal thinking, agitation, apathy and relapse of drug addiction may occur. INFERGEN should be used with extreme caution in patients who report a history of depression. Physicians should monitor all patients for evidence of depression and other psychiatric symptoms. Prior to initiation of INFERGEN therapy, physicians should inform patients of the possible development of depression and patients should be advised to report any sign or symptom of depression and/or suicidal ideation immediately. If patients develop psychiatric problems, including clinical depression, it is recommended that the patients be carefully monitored during treatment and in the 6-month follow-up period. If psychiatric symptoms persist or worsen, or suicidal ideation or aggressive behavior towards others are identified, it is recommended that treatment with INFERGEN be discontinued, and the patient followed, with psychiatric intervention as appropriate. In severe cases, INFERGEN should be stopped immediately and psychiatric intervention instituted .

## Cardiovascular Events
Cardiovascular events, which include hypotension, arrhythmia, tachycardia, cardiomyopathy, angina pectoris, and myocardial infarction, have been observed in patients treated with INFERGEN. INFERGEN should be used cautiously in patients with cardiovascular disease. Patients with a history of myocardial infarction and arrhythmic disorder who require INFERGEN therapy should be closely monitored . Patients with a history of significant or unstable cardiac disease should not be treated with INFERGEN/ribavirin combination therapy .

## 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 interferon alpha therapy, including INFERGEN. Patients who develop persistent or unexplained pulmonary infiltrates or pulmonary function impairment should discontinue treatment with INFERGEN. Recurrence of respiratory failure has been observed with interferon rechallenge. INFERGEN treatment should be suspended in patients who develop pulmonary infiltrates or pulmonary function impairment. Patients who resume interferon treatment should be closely monitored.

## Hepatic Failure
Chronic hepatitis C patients with cirrhosis may be at risk of hepatic decompensation when treated with interferon alphas, including INFERGEN. During treatment, patients clinical status and hepatic function should be closely monitored, and INFERGEN treatment should be immediately discontinued if symptoms of hepatic decompensation, such as jaundice, ascites, coagulopathy, or decreased serum albumin are observed .

## Renal Insufficiency
Increases in serum creatinine levels, including renal failure, have been observed in patients receiving INFERGEN. INFERGEN has not been studied in patients with renal insufficiency. It is recommended that renal function be evaluated in all patients starting INFERGEN alone or with ribavirin therapy. Patients with impaired renal function should be closely monitored for signs and symptoms of interferon toxicity, including increases in serum creatinine. Combination treatment with INFERGEN/ribavirin should not be used in patients with creatinine clearance <50 mL/min. .

## Cerebrovascular Disorders
Ischemic and hemorrhagic cerebrovascular events have been observed in patients treated with interferon alpha-based therapies, including INFERGEN. Events occurred in patients with few or no reported risk factors for stroke, including patients less than 45 years of age. Because these are spontaneous reports, estimates of frequency cannot be made and a causal relationship between interferon alpha-based therapies and these events is difficult to establish.

## Bone Marrow Toxicity
Interferon alphas suppress bone marrow function and may result in severe cytopenias including aplastic anemia. It is advised that complete blood counts be obtained pretreatment and monitored routinely during therapy. INFERGEN therapy should be discontinued in patients who develop severe decreases in neutrophil (< 0.5 x 109/L) or platelet counts (< 25 x 109/L).
INFERGEN should be used cautiously in patients with abnormally low peripheral blood cell counts or who are receiving agents that are known to cause myelosuppression. Transplantation patients or other chronically immunosuppressed patients should be treated with interferon alpha therapy with caution.
The use of ribavirin may result in a worsening of INFERGEN-induced neutropenia. Therefore combination treatment with INFERGEN/ribavirin should be used with caution in patients with low baseline neutrophil counts (< 1500 cells/mm3) and may require that therapy be discontinued in the event of a severe decrease in neutrophil count .

## Colitis
Hemorrhagic/ischemic colitis, sometimes fatal, has been observed within 12 weeks of interferon alpha therapies and has been reported in patients treated with INFERGEN. INFERGEN treatment should be discontinued immediately in patients who develop signs and symptoms of colitis.

## Pancreatitis
Pancreatitis, sometimes fatal, has been observed in patients treated with interferon alphas, including INFERGEN. INFERGEN should be suspended in patients with signs and symptoms suggestive of pancreatitis and discontinued in patients diagnosed with pancreatitis.

## Hypersensitivity
Serious acute hypersensitivity reactions have been reported following treatment with interferon alphas. If hypersensitivity reactions occur (e.g., urticaria, angioedema, bronchoconstriction, anaphylaxis), INFERGEN should be discontinued immediately and appropriate medical treatment instituted.

## Autoimmune Disorders
Development or exacerbation of autoimmune disorders (e.g., autoimmune thrombocytopenia, idiopathic thrombocytopenic purpura, psoriasis, rheumatoid arthritis, thyroiditis, interstitial nephritis, systemic lupus erythematosus (SLE)) have been reported in patients receiving interferon alpha therapies, including INFERGEN. INFERGEN should not be used in patients with autoimmune hepatitis  and should be used with caution in patients with other autoimmune disorders.

## Ophthalmologic Disorders
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 are induced or aggravated by treatment with INFERGEN or other interferons alpha. All patients should receive an eye examination at baseline. Patients with preexisting ophthalmologic disorders (e.g., diabetic or hypertensive retinopathy) should receive periodic ophthalmologic exams during interferon alpha treatment. Any patient who develops ocular symptoms should receive a prompt and complete eye examination. INFERGEN therapy should be discontinued in patients who develop new or worsening ophthalmologic disorders.

## Peripheral Neuropathy
Peripheral neuropathy has been reported when interferon alphas were given in combination with telbivudine. In one clinical trial, an increased risk and severity of peripheral neuropathy was observed with the combination use of telbivudine and pegylated interferon alfa-2a as compared to telbivudine alone. The safety and efficacy of telbivudine in combination with interferons for the treatment of chronic hepatitis B has not been demonstrated.

## Endocrine Disorders
INFERGEN should be administered with caution to patients with a history of endocrine disorders. Occurrence or aggravation of hyperthyroidism or hypothyroidism have been reported with INFERGEN. Hyperglycemia and diabetes mellitus have also been observed in patients treated with INFERGEN. Patients who develop these conditions during treatment that cannot be controlled with medication should not continue INFERGEN therapy.

## Laboratory Tests
Laboratory tests are recommended for all patients on INFERGEN therapy, as follows: prior to beginning treatment (baseline), 2 weeks after initiation of therapy, and periodically thereafter during the 24 or 48 weeks of therapy at the discretion of the physician. Following completion of INFERGEN therapy, any abnormal test values should be monitored periodically. The entrance criteria that were used for the clinical study of INFERGEN may be considered as a guideline to acceptable baseline values for initiation of treatment:
- Platelet count  75  109/L
- Hemoglobin concentration  10 g/dL
- ANC  1500  106/L
- Serum creatinine concentration  0.83 mL/second (> 50 mL/minute)
- Serum albumin concentration  25 g/L
- Bilirubin  1.4 mg/dL (with the exception of patients with Gilberts syndrome)
- TSH and T4 within normal limits
Neutropenia, thrombocytopenia, hypertriglyceridemia and thyroid disorders have been reported with administration of INFERGEN . Therefore, these laboratory parameters should be monitored closely.
Patients who have pre-existing cardiac abnormalities should have electrocardiograms administered before treatment with INFERGEN/ribavirin.