Patients should bemonitored for the following serious
conditions, some of which may become life threatening. Patients with
persistently severe or worsening signs or symptoms should be withdrawn from
therapy.
Usewith Ribavirin
Pregnancy
REBETOL may cause birth defects and death of the unborn child. REBETOL 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
2 forms of contraception and have monthly pregnancy tests [see BOXED
WARNING, CONTRAINDICATIONS, Patient
Counseling Information, and REBETOL package insert].
Anemia
Ribavirin caused hemolytic anemia in 10% of
PegIntron (peginterferon alfa-2b) /REBETOL-treated subjects within 1 to 4weeks of initiation of therapy.
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 REBETOL
therapy may result in a worsening of cardiac disease. Decrease in dosage or
discontinuation of REBETOL may be necessary [see DOSAGE AND ADMINISTRATION
and REBETOL package insert].
Neuropsychiatric Events
Life-threatening or fatal neuropsychiatric events, including
suicide, suicidal and homicidal ideation, depression, relapse of drug
addiction/overdose, and aggressive behavior sometimes directed towards others
have occurred in patients with and without a previous psychiatric disorder
during PegIntron (peginterferon alfa-2b) treatment and follow-up. Psychoses, hallucinations, bipolar
disorders, and mania have been observed in patients treated with interferon
alpha. PegIntron (peginterferon alfa-2b) should be used with extreme caution in patients with a history
of psychiatric disorders. Patients should be advised to report immediately any symptoms
of depression or suicidal ideation to their prescribing physicians. Physicians
should monitor all patients for evidence of depression and other psychiatric
symptoms. 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 is
identified, it is recommended that treatment with PegIntron (peginterferon alfa-2b) be discontinued,
and the patient followed, with psychiatric intervention as appropriate. In
severe cases, PegIntron (peginterferon alfa-2b) should be stopped immediately and psychiatric
intervention instituted [see DOSAGE AND ADMINISTRATION]. Cases of
encephalopathy have been observed in some patients, usually elderly, treated at
higher doses of PegIntron (peginterferon alfa-2b) .
Cardiovascular Events
Cardiovascular events, which include hypotension,
arrhythmia, tachycardia, cardiomyopathy, angina pectoris, and myocardial
infarction, have been observed in patients treated with PegIntron (peginterferon alfa-2b) . PegIntron (peginterferon alfa-2b)
should be used cautiously in patients with cardiovascular disease. Patients
with a history of myocardial infarction and arrhythmic disorder who require
PegIntron (peginterferon alfa-2b) therapy should be closely monitored [see WARNINGS AND PRECAUTIONS].
Patients with a history of significant or unstable cardiac disease should not
be treated with PegIntron (peginterferon alfa-2b) /REBETOL combination therapy [see REBETOL package
insert].
Endocrine Disorders
PegIntron (peginterferon alfa-2b) causes or aggravates hypothyroidism and
hyperthyroidism. Hyperglycemia has been observed in patients treated with
PegIntron (peginterferon alfa-2b) . Diabetes mellitus has been observed in patients treated with alpha
interferons. Patients with these conditions who cannot be effectively treated
by medication should not begin PegIntron (peginterferon alfa-2b) therapy. Patients who develop these
conditions during treatment and cannot be controlled with medication should not
continue PegIntron (peginterferon alfa-2b) therapy.
Ophthalmologic Disorders
Decrease or loss of vision, retinopathy including macular
edema, retinal artery or vein thrombosis, retinal hemorrhages and cotton wool
spots, optic neuritis, and papilledema may be induced or aggravated by
treatment with peginterferon alfa-2b or other alpha interferons. 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. Peginterferon alfa-2b treatment should be discontinued in patients
who develop new or worsening ophthalmologic disorders.
Cerebrovascular Disorders
Ischemic and hemorrhagic cerebrovascular events have been
observed in patients treated with interferon alfa-based therapies, including
PegIntron (peginterferon alfa-2b) . 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 alfa-based therapies and these events is
difficult to establish.
Bone Marrow Toxicity
PegIntron (peginterferon alfa-2b) suppresses bone marrow function, sometimes resulting in severe cytopenias.
PegIntron (peginterferon alfa-2b) should be discontinued in patients who develop severe decreases in
neutrophil or platelet counts [see DOSAGE AND ADMINISTRATION].
Ribavirin may potentiate the neutropenia induced by interferon alpha. Very rarely
alpha interferons may be associated with aplastic anemia.
Autoimmune Disorders
Development or exacerbation of autoimmune disorders (e.g., thyroiditis, thrombotic
thrombocytopenic purpura, idiopathic thrombocytopenic purpura, rheumatoid arthritis,
interstitial nephritis, systemic lupus erythematosus, and psoriasis) have been
observed in patients receiving PegIntron (peginterferon alfa-2b) .
PegIntron (peginterferon alfa-2b) should be used with caution in patients with autoimmune disorders.
Pancreatitis
Fatal and nonfatal pancreatitis have been observed in
patients treated with alpha interferon. PegIntron (peginterferon alfa-2b) therapy should be suspended
in patients with signs and symptoms suggestive of pancreatitis and discontinued
in patients diagnosed with pancreatitis.
Colitis
Fatal and nonfatal ulcerative or hemorrhagic/ischemic
colitis have been observed within 12 weeks of the start of alpha interferon
treatment. Abdominal pain, bloody diarrhea, and fever are the typical
manifestations. PegIntron (peginterferon alfa-2b) treatment should be discontinued immediately in
patients who develop these signs and symptoms. The colitis usually resolves
within 1 to 3 weeks of discontinuation of alpha interferons.
Pulmonary Disorders
Dyspnea, pulmonary infiltrates, pneumonia, bronchiolitis
obliterans, interstitial pneumonitis, and sarcoidosis, some resulting in
respiratory failure or patient deaths, may be induced or aggravated by
PegIntron (peginterferon alfa-2b) or alpha interferon therapy. Recurrence of respiratory failure has
been observed with interferon re-challenge. PegIntron (peginterferon alfa-2b) combination 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 (CHC) patients with cirrhosismay be at
risk of hepatic decompensation and death when treated with alpha interferons,
including PegIntron (peginterferon alfa-2b) . Cirrhotic CHC patients coinfected with HIV receiving
highly active antiretroviral therapy (HAART) and alpha interferons with or
without ribavirin appear to be at increased risk for the development of hepatic
decompensation compared to patients not receiving HAART. During treatment,
patients' clinical status and hepatic function should be closely monitored, and
PegIntron (peginterferon alfa-2b) treatment should be immediately discontinued if decompensation (Child-Pugh
score > 6) is observed [see CONTRAINDICATIONS].
Patients with Renal Insufficiency
Increases in serum creatinine levels have been observed in
patients with renal insufficiency receiving interferon alpha products,
including PegIntron (peginterferon alfa-2b) . Patients with impaired renal function should be closely
monitored for signs and symptoms of interferon toxicity, including increases in
serum creatinine, and PegIntron (peginterferon alfa-2b) dosing should be adjusted accordingly or
discontinued [see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION].
PegIntron (peginterferon alfa-2b) monotherapy should be used with caution in patients with creatinine
clearance < 50 mL/min; the potential risks should be weighed against the
potential benefits in these patients. Combination therapy with REBETOL must not
be used in patients with creatinine clearance < 50 mL/min [see REBETOL
Package Insert].
Hypersensitivity
Serious, acute hypersensitivity reactions (e.g., urticaria,
angioedema, bronchoconstriction, anaphylaxis) and cutaneous eruptions
(Stevens-Johnson syndrome, toxic epidermal necrolysis) have been rarely
observed during alpha interferon therapy. If such a reaction develops during
treatment with PegIntron (peginterferon alfa-2b) , discontinue treatment and institute appropriate
medical therapy immediately. Transient rashes do not necessitate interruption
of treatment.
Laboratory Tests
PegIntron (peginterferon alfa-2b) alone or in combination with ribavirin may cause
severe decreases in neutrophil and platelet counts, and hematologic, endocrine
(e.g.,TSH), and hepatic abnormalities. Transient elevations in ALT (2- to
5-fold above baseline)were observed in 10%of subjects treated with PegIntron (peginterferon alfa-2b) ,
and were not associated with deterioration of other liver functions.
Triglyceride levels are frequently elevated in patients receiving alpha
interferon therapy including PegIntron (peginterferon alfa-2b) and should be periodically monitored.
Patients on PegIntron (peginterferon alfa-2b) or PegIntron (peginterferon alfa-2b) /REBETOL combination
therapy should have hematology and blood chemistry testing before the start of
treatment and then periodically thereafter. In the adult clinical trial CBC
(including hemoglobin, neutrophil, and platelet counts) and chemistries
(including AST, ALT, bilirubin, and uric acid) were measured during the
treatment period at Weeks 2, 4, 8, and 12, and then at 6-week intervals or more
frequently if abnormalities developed. In pediatric subjects, the same
laboratory parameters were evaluated with additional assessment of hemoglobin
at treatment Week 6. TSH levels were measured every 12 weeks during the
treatment period. HCV RNA should be measured periodically during treatment [see
DOSAGE AND ADMINISTRATION].
Patients who have pre-existing cardiac abnormalities should
have electrocardiograms done before treatment with PegIntron (peginterferon alfa-2b) /REBETOL.
Dental and Periodontal Disorders
Dental and periodontal disorders have been reported in
patients receiving PegIntron (peginterferon alfa-2b) /REBETOL combination therapy. In addition, dry
mouth could have a damaging effect on teeth and mucous membranes of the mouth
during long-term treatment with the combination of REBETOL and PegIntron (peginterferon alfa-2b) .
Patients should brush their teeth thoroughly twice daily and have regular
dental examinations. If vomiting occurs, patients should be advised to rinse
out their mouth thoroughly afterwards.
Triglycerides
Elevated triglyceride levels have been observed in patients
treated with interferon alpha, including PegIntron (peginterferon alfa-2b) therapy. Hypertriglyceridemia
may result in pancreatitis [see WARNINGS AND PRECAUTIONS]. Elevated
triglyceride levels should be managed as clinically appropriate. Discontinuation
of PegIntron (peginterferon alfa-2b) therapy should be considered for patients with symptoms of
potential pancreatitis, such as abdominal pain, nausea, or vomiting, and
persistently elevated triglycerides (e.g., triglycerides > 1000 mg/dL).
Impact on Growth – Pediatric Use
Data on the effects of PegIntron (peginterferon alfa-2b) plus REBETOL on growth come
from an open-label study in subjects 3 through 17 years of age, and weight and
height changes are compared to US normative population data. In general, the
weight and height gain of pediatric subjects treated with PegIntron (peginterferon alfa-2b) plus REBETOL
lags behind that predicted by normative population data for the entire length
of treatment. After about 6 months posttreatment (follow-up Week 24), subjects
had weight gain rebounds and regained their weight to 53rd percentile, above
the average of the normative population and similar to that predicted by their
average baseline weight (57th percentile). After about 6 months posttreatment, height
gain stabilized, and subjects treated with PegIntron (peginterferon alfa-2b) plus REBETOL had an
average height percentile of 44th percentile, which was less than the average
of the normative population and less than their average baseline height (51st
percentile). Severely inhibited growth velocity ( < 3rd percentile) was observed
in 70% of the subjects while on treatment. Of the subjects experiencing
severely inhibited growth, 20%had continued inhibited growth velocity ( < 3rd
percentile) after 6 months of follow-up.
Among the boys studied, the age groups of 3 to 11 years old
and 12 to 17 years old had similar height percentile decreases of approximately
5 percentiles after 6 months posttreatment; weight gain continued to be similar
to their average baseline percentile. Girlswhowere 3 to 11 years old and
treated for 48 weeks had the largest average drop in height and weight
percentiles (13 percentiles and 7 percentiles, respectively), whereas girls 12
to 17 years old continued along their average baseline height and weight
percentiles after 6 months posttreatment.
Patient Counseling Information
A patient should self-inject PegIntron (peginterferon alfa-2b) only if it has been
determined that it is appropriate, the patient agrees to medical follow-up as
necessary, and training in proper injection technique has been given to
him/her.
Medication Guide
Patients receiving PegIntron (peginterferon alfa-2b) alone or in combination with REBETOL should be
directed in its appropriate use, informed of the benefits and risks associated
with treatment, and referred to the MEDICATION GUIDES
for PegIntron (peginterferon alfa-2b) and, if applicable, REBETOL (ribavirin).
Pregnancy
Patients must be informed that REBETOL may cause birth defects and death of
the unborn child. Extreme care must be taken to avoid pregnancy in female patients
and in female partners of male patients during treatment with combination PegIntron (peginterferon alfa-2b) /REBETOL
therapy and for 6 months post therapy. Combination PegIntron (peginterferon alfa-2b) /REBETOL therapy
should not be initiated until a report of a negative pregnancy test has been
obtained immediately prior to initiation of therapy. It is recommended that
patients undergo monthly pregnancy tests during therapy and for 6months posttherapy
[see CONTRAINDICATIONS, Use
in Specific Populations, and REBETOL package insert].
HCV Transmission
Inform patients that there are no data regarding whether
PegIntron (peginterferon alfa-2b) therapy will prevent transmission of HCV infection to others. Also,
it is not known if treatment with PegIntron (peginterferon alfa-2b) will cure hepatitis C or prevent
cirrhosis, liver failure, or liver cancer that may be the result of infection with
the hepatitis C virus.
Laboratory Evaluations, Hydration, “Flu-like” Symptoms
Patients should be advised that laboratory evaluations are required before
starting therapy and periodically thereafter [see WARNINGS AND PRECAUTIONS].
It is advised that patients be well-hydrated, especially during the initial
stages of treatment. “Flu-like” symptoms associated with administration
of PegIntron (peginterferon alfa-2b) may be minimized by bedtime administration of PegIntron (peginterferon alfa-2b) or by use
of antipyretics.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenesis and Mutagenesis
PegIntron (peginterferon alfa-2b) has not been tested for its carcinogenic
potential. Neither PegIntron (peginterferon alfa-2b) nor its components, interferon or
methoxypolyethylene glycol, caused damage to DNA when tested in the standard
battery of mutagenesis assays, in the presence and absence of metabolic
activation.
Use with Ribavirin
Ribavirin is genotoxic and mutagenic and should be considered
a potential carcinogen. See REBETOL package insert for additional warnings
relevant to PegIntron (peginterferon alfa-2b) therapy in combination with ribavirin.
Impairment of Fertility
PegIntron (peginterferon alfa-2b) may impair human fertility. Irregular menstrual
cycles were observed in female cynomolgus monkeys given subcutaneous injections
of 4239 mcg/m² PegIntron (peginterferon alfa-2b) alone every other day for 1 month (approximately 345
times the recommended weekly human dose based upon body surface area). These
effects included transiently decreased serum levels of estradiol and
progesterone, suggestive of anovulation. Normal menstrual cycles and serum
hormone levels resumed in these animals 2 to 3 months following cessation of
PegIntron (peginterferon alfa-2b) treatment. Every other day dosing with 262mcg/m² (approximately 21
times the weekly human dose) had no effects on cycle duration or reproductive
hormone status. The effects of PegIntron (peginterferon alfa-2b) on male fertility have not been
studied.
Use In Specific Populations
Pregnancy
PegIntron (peginterferon alfa-2b) Monotherapy
Pregnancy Category C: Nonpegylated interferon
alfa-2b has been shown to have abortifacient effects in Macaca mulatta (rhesus
monkeys) at 15 and 30 million IU/kg (estimated human equivalent of 5 and 10
million IU/kg, based on body surface area adjustment for a 60-kg adult).
PegIntron (peginterferon alfa-2b) should be assumed to also have abortifacient potential. There are no
adequate and well-controlled studies in pregnant women. PegIntron (peginterferon alfa-2b) therapy is to
be used during pregnancy only if the potential benefit justifies the potential
risk to the fetus. Therefore, PegIntron (peginterferon alfa-2b) is recommended for use in fertile women
only when they are using effective contraception during the treatment period.
Use with Ribavirin
Pregnancy Category X: Significant teratogenic and/or
embryocidal effects have been demonstrated in all animal species exposed to
ribavirin. REBETOL therapy is contraindicated in women who are pregnant and in
the male partners of women who are pregnant [see CONTRAINDICATIONS and
the REBETOL Package Insert].
A Ribavirin Pregnancy Registry has been established to
monitor maternal-fetal outcomes of pregnancies in female patients and female
partners of male patients exposed to ribavirin during treatment and for 6
months following cessation of treatment. Physicians and patients are encouraged
to report such cases by calling 1-800-593-2214.
Nursing Mothers
It is not known whether the components of PegIntron (peginterferon alfa-2b) and/or
REBETOL are excreted in human milk. Studies in mice have shown that mouse
interferons are excreted in breast milk. Because of the potential for adverse
reactions from the drug in nursing infants, a decision must be made whether to discontinue
nursing or discontinue the PegIntron (peginterferon alfa-2b) and REBETOL treatment, taking into account
the importance of the therapy to the mother.
Pediatric Use
Safety and effectiveness in pediatric patients below the age
of 3 years have not been established. Clinical trials in pediatric patients
< 3 years of age are not considered feasible due to the small proportion of
patients in this age group requiring treatment for CHC.
Geriatric Use
In general, younger patients tend to respond better than
older patients to interferon-based therapies. Clinical studies of PegIntron (peginterferon alfa-2b)
alone or in combination with REBETOL did not include sufficient numbers of
subjects aged 65 and over, however, to determine whether they respond
differently than younger subjects. Treatment with alpha interferons, including
PegIntron (peginterferon alfa-2b) , is associated with neuropsychiatric, cardiac, pulmonary, GI, and
systemic (flu-like) adverse effects. Because these adverse reactions may be
more severe in the elderly, caution should be exercised in the use of PegIntron (peginterferon alfa-2b)
in this population. This drug is known to be substantially excreted by the
kidney. Because elderly patients aremore likely to have decreased renal
function, the risk of toxic reactions to this drug may be greater in
patientswith impaired renal function [see CLINICAL PHARMACOLOGY].When
using PegIntron (peginterferon alfa-2b) / REBETOL therapy, refer also to the REBETOL Package Insert.
Organ Transplant Recipients
The safety and efficacy of PegIntron (peginterferon alfa-2b) alone or in combination
with REBETOL for the treatment of hepatitis C in liver or other organ
transplant recipients have not been studied. In a small (n=16) single-center,
uncontrolled case experience, renal failure in renal allograft recipients
receiving interferon alpha and ribavirin combination therapy was more frequent
than expected from the center's previous experience with renal allograft
recipients not receiving combination therapy. The relationship of the renal
failure to renal allograft rejection is not clear.
HIV or HBV Coinfection
The safety and efficacy of PegIntron (peginterferon alfa-2b) /REBETOL for the
treatment of patients with HCV coinfected with HIV or HBV have not been
established.
Last reviewed on RxList: 7/10/2009
This monograph has been modified to include the generic and brand name in many instances.