Pirfenol Tablet is a prescription medication used to treat idiopathic pulmonary fibrosis, reducing lung scarring and swelling. It is best taken with food daily, with the dose and frequency determined by the doctor. Common side effects include insomnia, headache, dizziness, dyspepsia, nausea, diarrhea, and photosensitivity. It may cause weight loss, and doctors may perform liver function tests. Patients with liver or kidney disease, other medications, sun-sensitive skin, or pregnant or breastfeeding should inform their doctor.