Baricitinib affects immune-system activity and can cause adverse reactions ranging from relatively mild symptoms to serious complications.
Commonly reported reactions
Depending on the indication and clinical population, reported adverse reactions include:
- Upper respiratory infections
- Headache
- Nausea
- Acne
- Increased cholesterol
- Elevated liver enzymes
- Changes in blood counts
- Herpes virus infections
The specific frequency varies between indications and study populations.
Serious infections
Because baricitinib suppresses immune signaling, serious infections can occur.
These may include:
- Tuberculosis
- Bacterial infections
- Viral infections
- Fungal infections
- Opportunistic infections
The current U.S. boxed warning specifically highlights serious infections that may lead to hospitalization or death.
Blood clots
Thrombosis, including venous and arterial thrombosis, has occurred in patients receiving baricitinib.
Symptoms requiring urgent assessment may include:
- Sudden shortness of breath
- Chest pain
- Coughing blood
- One-sided leg swelling
- Sudden weakness
- Sudden difficulty speaking
Cardiovascular events
JAK inhibitors carry important cardiovascular safety warnings.
Major adverse cardiovascular events include:
- Cardiovascular death
- Heart attack
- Stroke
The current U.S. boxed warning highlights increased MACE risk observed with another JAK inhibitor compared with TNF blockers in certain rheumatoid arthritis populations.
Cancer risk
Malignancies have occurred in patients treated with baricitinib.
The current U.S. warning discusses malignancy risk and findings from another JAK inhibitor compared with TNF blockers in rheumatoid arthritis patients.
Gastrointestinal perforation
Gastrointestinal perforation has been reported.
Patients who develop significant or unexplained abdominal pain should seek medical evaluation, particularly if they have risk factors.
Hypersensitivity
Serious allergic reactions can occur. Baricitinib should be discontinued if a serious hypersensitivity reaction develops.