How does this medication work? What will it do for me?

Pirfenidone belongs to the class of medications known as antifibrotics. It is also an anti-inflammatory. Pirfenidone is used to treat adults with mild-to-moderate idiopathic pulmonary fibrosis (lung scarring), also called IPF. IPF is a condition in which the lungs become thickened, stiff, or scarred over a long period of time. How pirfenidone works is not completely understood, but it may reduce inflammation and fibrosis in the lungs and may slow down the worsening of IPF.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Each opaque capsule with a blue body and a gold cap, imprinted with "InterMune® 267 mg" on the gold cap, contains pirfenidone 267 mg. Nonmedicinal ingredients: black iron oxide, croscarmellose sodium, gelatin, indigo carmine, magnesium stearate, microcrystalline cellulose, povidone, red iron oxide, shellac, titanium dioxide, and yellow iron oxide.

How should I use this medication?

For the first 7 days of treatment, the dose of pirfenidone is 1 capsule 3 times a day. For the next 7 days (day 8 to day 14), increase the dose to 2 capsules 3 times a day. From day 15 onwards, increase the dose to 3 capsules 3 times per day. Pirfenidone should be taken with food, or during or after a meal to reduce side effects such as stomach problems and dizziness. Swallow each capsule whole with water. Your doctor may adjust your dose depending on how you tolerate pirfenidone.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, continue with the next dose in your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice. If you miss taking this medication for 14 days in a row or more, contact your doctor, as you will need to re-start treatment with increasing doses.

Store this medication at room temperature and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take pirfenidone if you:

  • are allergic to pirfenidone or any ingredients of the medication
  • are taking any medications that may increase the amount of pirfenidone in your body (e.g., ciprofloxacin, fluvoxamine)
  • have severe kidney or liver problems

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal pain
  • bloating
  • constipation
  • decreased appetite
  • diarrhea
  • difficulty sleeping
  • hot flushes
  • gas
  • headache
  • indigestion, heartburn, or acid reflux
  • itchy, dry, or red skin
  • muscle or joint aches or pains
  • nausea
  • rash
  • sun sensitivity (e.g., sunburn, skin rash, blistering or peeling skin)
  • sweating
  • taste changes
  • tiredness
  • vomiting
  • weight loss

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • chest pain
  • dizziness
  • symptoms of infection (fever, cough, sinus congestion or pain, difficult or painful urination)
  • 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)

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • signs of a serious allergic reaction (e.g., hives; difficulty breathing or swallowing; or swelling of the face, lips, tongue, or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

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.

What other drugs could interact with this medication?

There may be an interaction between pirfenidone and any of the following:

  • abiraterone
  • amiodarone
  • amlodipine
  • birth control pills
  • bupropion
  • carbamazepine
  • cimetidine
  • cinacalcet
  • ciprofloxacin
  • cyproterone
  • deferasirox
  • duloxetine
  • esomeprazole
  • fluconazole
  • fluoxetine
  • fluvoxamine
  • gemfibrozil
  • grapefruit juice
  • methoxsalen
  • mexiletine
  • miconazole
  • moclobemide
  • norfloxacin
  • ofloxacin
  • omeprazole
  • paroxetine
  • peginterferon alfa-2b
  • phenobarbital
  • phenytoin
  • porfimer
  • primaquine
  • primidone
  • quinidine
  • rifampin
  • terbinafine
  • tranylcypromine
  • vemurafenib
  • voriconazole

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.