Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Fatigue and dizziness: Pirfenidone can cause fatigue and dizziness. Do not drive or operate machinery until you know that this medication does not affect your ability to perform these activities safely. To reduce dizziness, take this medication with food.
Kidney function: If you have kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you have severely reduced kidney function or are receiving dialysis treatment, you should not take this medication.
Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.
If you experience symptoms of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools, itching) while taking this medication, contact your doctor.
If you have severe liver disease, you should not take this medication.
Sun sensitivity: Pirfenidone may increase the sensitivity of your skin to the sun. Avoid exposure to direct and indirect sunlight (including sunlamps and window light), use an effective sunblock daily (at least SPF 50 for UVA and UVB), and wear clothing that protects you from the sun (e.g., hat, long-sleeves) while taking this medication. If you get a skin reaction (e.g., rash, sunburn, blistering, peeling) from the sun, contact your doctor.
Weight loss: Pirfenidone may cause loss of appetite and weight loss. Your doctor will monitor your weight while you are taking this medication.
Pregnancy: This medication should not be used during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if pirfenidone passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for anyone under the age of 18.