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Actimmune Side Effects

Generic name: interferon gamma-1b

Medically reviewed by Last updated on May 15, 2022.

Note: This document contains side effect information about interferon gamma-1b. Some of the dosage forms listed on this page may not apply to the brand name Actimmune.


Common side effects of Actimmune include: fever, flu-like symptoms, headache, chills, erythema at injection site, and tenderness at injection site. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to interferon gamma-1b: solution

Side effects requiring immediate medical attention

Along with its needed effects, interferon gamma-1b (the active ingredient contained in Actimmune) 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 or nurse immediately if any of the following side effects occur while taking interferon gamma-1b:

More common

  • Chills
  • fever

Less common

  • Black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • confusion
  • cough or hoarseness
  • loss of balance control
  • lower back or side pain
  • mask-like face
  • painful or difficult urination
  • pinpoint red spots on the skin
  • shuffling walk
  • sore throat
  • stiffness of the arms or legs
  • trembling and shaking of the hands and fingers
  • trouble breathing
  • trouble speaking or swallowing
  • trouble thinking or concentrating
  • trouble walking
  • ulcers, sores, or white spots in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Incidence not known

  • Abdominal or stomach pain or tenderness
  • change in walking and balance
  • clay colored stools
  • clumsiness or unsteadiness
  • dark urine
  • decreased appetite
  • decreased frequency or amount of urine
  • general feeling of discomfort or illness
  • headache
  • increased thirst
  • itching or skin rash
  • joint or muscle pain
  • loss of appetite
  • lower back or side pain
  • muscle aches and pains
  • nausea and vomiting
  • numbness or tingling of the face, hands, or feet
  • painful or difficult urination
  • pale skin
  • redness and soreness of the eyes
  • runny nose
  • shivering skin
  • sweating
  • swelling of the face, fingers, or lower legs
  • trouble sleeping
  • weight gain
  • yellow eyes or skin

Side effects not requiring immediate medical attention

Some side effects of interferon gamma-1b 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:

More common

  • Diarrhea
  • redness or tenderness at the injection site

Less common

For Healthcare Professionals

Applies to interferon gamma-1b: subcutaneous solution


Very common (10% or more): Diarrhea, nausea, vomiting

Common (1% to 10%): Abdominal pain

Frequency not reported: Pancreatitis, GI hemorrhage[Ref]


Very common (10% or more): Rash[Ref]


Very common (10% or more): Injection site pain[Ref]


Frequency not reported: Cardiac failure, myocardial infarction, tachyarrhythmia, atrioventricular block, transient ischemic attack, deep vein thrombosis, hypotension, syncope[Ref]

Nervous system

Very common (10% or more): Headache

Frequency not reported: Convulsions, Parkinsonian gait, Parkinsonian rest tremor, gait disturbance[Ref]


Frequency not reported: Pulmonary embolism, interstitial lung disease, bronchospasm, tachypnea, chest discomfort[Ref]


Frequency not reported: Neutropenia, thrombocytopenia[Ref]


Frequency not reported: Renal failure, proteinuria[Ref]


Frequency not reported: Hyponatremia, hypoglycemia, hypertriglyceridemia[Ref]


Common (1% to 10%): Myalgia, arthralgia, back pain


Common (1% to 10%): Depression

Frequency not reported: Confusion, disorientation, hallucination[Ref]


Very common (10% or more): Hepatic enzymes increased[Ref]


Very common (10% or more): Fever, chills, fatigue[Ref]


1. "Product Information. Actimmune (interferon gamma-1b)." Horizon Therapeutics USA Inc (2019):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.