Last reviewed on RxList: 1/4/2019
Sylatron Side Effects Center

Last reviewed on RxList 1/4/2019

Sylatron (peginterferon alfa-2b) is a biological response modifier prescribed as a supplemental, post-surgical treatment for dangerous skin cancers (melanomas). Common side effects of Sylatron include:

  • headache,
  • joint or muscle pain,
  • nausea,
  • dry mouth,
  • loss of appetite,
  • weight loss,
  • dizziness,
  • sleep problems (insomnia),
  • feeling mildly anxious,
  • depressed or irritable, or
  • pain/redness/swelling/irritation where the medicine was injected

Serious side effects of Sylatron include:

  • depression,
  • suicidal ideation,
  • psychosis, and
  • other neuropsychiatric disorders

Sylatron is administered as a subcutaneous injection. Sylatron may impair human fertility. There are no adequate and well-controlled studies of Sylatron in pregnant women. Sylatron should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is not known whether the components of Sylatron are excreted in human 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 Sylatron treatment, taking into account the importance of the therapy to the mother.

Our Sylatron (peginterferon alfa-2b) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Sylatron Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives, or a rash that spreads and causes blistering and peeling; chest pain, anxiety, difficult breathing; swelling of your face, lips, tongue, or throat.

Tell your doctor right away if you have unusual changes in mood or behavior, such as: depression, irritability, feeling hostile or aggressive, hallucinations, thoughts about hurting yourself, or falling back into a previous pattern of drug addiction. These symptoms may occur during treatment and up to 6 months after your last dose.

Peginterferon alfa-2b may cause serious or fatal side effects. Call your doctor at once if you have:

  • severe stomach pain with bloody diarrhea;
  • new or worsening cough, cough with mucus, trouble breathing;
  • numbness, tingling, or burning in your arms or legs;
  • sudden numbness or weakness, slurred speech, problems with balance;
  • vision changes;
  • low blood cell counts--fever, chills, tiredness, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or short of breath;
  • high blood sugar--increased thirst, increased urination, dry mouth, fruity breath odor;
  • pancreatitis--severe pain in your upper stomach spreading to your back, nausea and vomiting;
  • thyroid problems--weight changes, skin changes, thinking problems, feeling hot or cold all the time; or
  • worsening liver symptoms--swelling around your midsection, nausea, diarrhea, loss of appetite, confusion, drowsiness, yellowing of the skin or eyes, loss of consciousness.

Combination treatment with peginterferon alfa-2b and ribavirin can affect growth in children. Tell your doctor if you think your child is not growing at a normal rate while using this combination.

Common side effects may include:

  • fever, chills, feeling weak or tired;
  • low white blood cells counts;
  • mood changes, feeling anxious or irritable;
  • headache, muscle pain;
  • nausea, vomiting, loss of appetite;
  • abnormal liver function tests; or
  • redness, swelling, or other irritation where the medicine was injected.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Sylatron (Peginterferon alfa-2b)


Self-examination is important in the detection of skin cancer. See Answer
Sylatron Professional Information


The following serious adverse reactions are discussed in greater detail in other sections of the labeling:

  • Depression and Other Neuropsychiatric Adverse Reactions [see WARNINGS AND PRECAUTIONS]
  • Cardiovascular Adverse Reactions [see WARNINGS AND PRECAUTIONS]
  • Retinopathy and Other Serious Ocular Adverse Reactions [see WARNINGS AND PRECAUTIONS]
  • Hepatic Failure [see WARNINGS AND PRECAUTIONS]
  • Endocrinopatliies [see WARNINGS AND PRECAUTIONS]

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

The data described below reflect exposure to SYLATRON in 608 patients with surgically resected. AJCC Stage III melanoma. SYLATRON was studied in an open label, multicenter, randomized, observation controlled trial. The median age of the population was 50 years with 10% of patients 65 years or older, and 42% were female. Fourteen percent of patients completed the 5 year treatment schedule.

Patients randomized to SYLATRON were to receive total doses of 48 mcg/kg (6 mcg/kg subcutaneous once weekly for 8 doses), and 780 mcg/kg (3 mcg/kg subcutaneous once weekly until disease recurrence or for up to 5 years), as tolerated. The median total dose received was 42 mcg/kg (range: 6 to 78 mcg/kg) for the first 8 doses, and 136 mcg/kg (range: 1 to 774 mcg/kg) for doses 9 to 260.

Serious adverse events were reported in 199 (33%) patients who received SYLATRON and 94 (15%) patients in the observation group.

The most common adverse reactions experienced by SYLATRON-treated patients were fatigue (94%). increased ALT (77%). increased AST (77%). pyrexia (75%). headache (70%). anorexia (69%). myalgia (68%), nausea (64%), chills (63%), and injection site reaction (62%). The most common serious adverse reactions were fatigue (7%), increased ALT (3%). increased AST (3%), and pyrexia (3%) in the SYLATRON-treated group vs. <1% in the observation group for these reactions.

Thirty three percent of patients receiving SYLATRON discontinued treatment due to adverse reactions. The most common adverse reactions present at the time of treatment discontinuation were fatigue (27%), depression (17%), anorexia (15%), increased ALT (14%), increased AST (14%), myalgia (13%), nausea (13%), headache (13%), and pyrexia (11%). Adverse events that occurred in the clinical study at >5% incidence in the SYLATRON- treated group and with a greater incidence in patients receiving SYLATRON as compared to the observation group are presented in Table 4.

Table 4: Incidence of Adverse Reactions(*) Occurring in ≥5% of Melanoma Patients Treated with SYLATRON and with a Greater Incidence as Compared to Observation

Adverse Reaction SYLATRON
All Grades (%) Grade 3 and 4 (%) All Grades (%) Grade 3 and 4 (%)
Any Adverse Reaction 100 51 82 18
General Disorders and Administrative Site Conditions
Fatigue 94 16 41 1
Pyrexia 75 4 9 0
Chills 63 1 6 0
Injection Site Reaction 62 1.8 0 0
ALT or AST Increased 77 11 26 1
Blood Alkaline Phosphatase Increased 23 0 11 <1
Weight Decreased 11 <1 1 <1
GGT Increased 8 4 1 <1
Proteinuria 7 0 3 0
Anemia 6 <1 2 <1
Nervous System Disorders
Headache 70 4 19 1
Dysgeusia 38 0 1 0
Dizziness 35 2 11 <1
Olfactory Nerve Disorder 23 0 1 0
Paraesthesia 21 <1 14 <1
Metabolism and Nutrition Disorders
Anorexia 69 3 13 0
Musculoskeletal and Connective Tissue Disorders
Myalgia 68 4 23 <1
Arthralgia 51 3 22 1
Gastrointestinal Disorders
Nausea 64 3 11 <1
Diarrhea 37 1 8 <1
Vomiting 26 1 4 0
Psychiatric Disorders
Depression 59 7 24 <1
Skin and Subcutaneous Tissue Disorders
Exfoliative Rash 36 1 4 0
Alopecia 34 0 1 0
Respiratory, Thoracic and Mediastinal Disorders
Dyspnea 6 1 2 1
Cough 5 <1 2 0
*Adverse reactions were graded using NCI CTCAE, V.2.0.


As with all therapeutic proteins, there is potential for immunogenieity. In a clinical study conducted in patients with melanoma, the incidence of binding antibodies to peg-interferon alfa-2b was approximately 35% (50/144 patients). Among the patients who tested positive for binding antibodies, one patient developed neutralizing antibodies. The impact of antibody formation on pharmacokinetics, safety and efficacy of peg-interferon alfa-2b could not be assessed based on limited available data.

The incidence of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors, including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to SYLATRON with the incidence of antibodies to other products may be misleading.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of peginterferon alfa-2b as monotherapy and in combination with ribavirin in chronic hepatitis C (CHC) patients. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Blood and Lymphatic System Disorders

pure red cell aplasia, thrombotic thrombocytopenic purpura

Cardiac Disorders


Ear and Labyrinth Disorders

hearing loss, vertigo, hearing impairment

Endocrine Disorders

diabetic ketoacidosis

Eye Disorders

Vogt-Koyanagi-Harada syndrome

Gastrointestinal Disorders

aphthous stomatitis, pancreatitis, colitis, tongue pigmentation

Infusion Reactions

angioedema, urticaria, bronchoconstriction

Immune System Disorders

systemic lupus erythematosus, erythema multiforme, thyroiditis, thrombotic thrombocytopenic purpura, idiopathic thrombocytopenic purpura, rheumatoid arthritis, interstitial nephritis, and systemic lupus erythematosus


sepsis, hepatitis B virus reactivation in HCV/HBV co-infected patients

Metabolism and Nutrition Disorders


Musculoskeletal and Connective Tissue Disorders

rhabdomyolysis, myositis

Nervous System Disorders

seizures, memory loss, peripheral neuropathy, paraesthesia, migraine headache

Respiratory, Thoracic and Mediastinal Disorders

dyspnea, pulmonary infiltrates, pneumonia, bronchiolitis obliterans, interstitial pneumonitis, sarcoidosis, pulmonary hypertension, and pulmonary fibrosis

Skin and Subcutaneous Tissue Disorders

Stevens-Johnson syndrome, toxic epidermal necrolysis, psoriasis

Vascular Disorders

hypertension, hypotension, stroke

Read the entire FDA prescribing information for Sylatron (Peginterferon alfa-2b)

© Sylatron Patient Information is supplied by Cerner Multum, Inc. and Sylatron Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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