What are the side effects of pirfenidone?

Pirfenidone (Pirfenidone), sold under trade names such as Pirespa, is a drug used to treat idiopathic pulmonary fibrosis. It reduces pulmonary fibrosis by downregulating growth factors and the production of type I and type II procollagen.

Get emergency medical help if you have signs of an allergic reaction (hives, difficulty breathing, swelling of the face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple rash with blisters and swelling) while you are using pirfenidone.

Seek medical treatment if you have a serious drug reaction that affects many parts of the body. Symptoms may include rash, fever, swollen glands, muscle pain, severe weakness, unusual bruising, or yellowing of the skin or eyes.

Pirfenidone may cause serious side effects. Call your doctor right away if you have: new or worsening problems with your stomach or esophagus, such as nausea, vomiting, diarrhea, indigestion, heartburnand pain in your stomach or esophagus; a rash on your face or arms that worsens in the sun; or liver problems—loss of appetite, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects of pirfenidone may include: nausea, vomiting, loss of appetite; stomach pain, heartburn, upset stomach; diarrhea; headache, dizziness, feeling tired; weight loss; joint pain; cold symptoms such as nasal congestion, sneezing, sore throat; or sleep problems (insomnia). This is not a complete list of side effects, and other side effects may occur.

It is important to note that the side effects of pirfenidone may vary from individual to individual and may not occur in everyone. Patients should pay close attention to their physical condition while taking pirfenidone, undergo regular examinations, and adjust the drug dosage as directed by their doctor. If you develop any severe, persistent or progressive symptoms, seek medical attention immediately.