Pirfenidone
Pirfenidone is an oral medicine used to treat idiopathic pulmonary fibrosis (IPF). Pirfenidone is used for Idiopathic pulmonary fibrosis (IPF).
Pronunciation: pronunciation varies by local usage.
- Generic name
- pirfenidone
- Brand names
- Esbriet
- Drug class
- Pyridone (antifibrotic/anti-inflammatory agent)
- Form
- Capsule or film-coated tablet, depending on country and product
- Route
- Oral
- Legal status
- Prescription-only medicine
Availability and supply rules vary by country
Trade names by country:
Australia: · Full directory
What pirfenidone is and how it works
Pirfenidone is an oral medicine used to treat idiopathic pulmonary fibrosis (IPF). It belongs to a class of medications called pyridones. Its exact mechanism in IPF is not fully established, but it may work by blocking certain natural substances involved in causing fibrosis. (1) (2) (3)
Pirfenidone is a treatment for IPF. It must be started and supervised by a specialist experienced in IPF.
Mechanism of action: how pirfenidone works
The mechanism of action in IPF has not been fully established. Data suggest pirfenidone exerts both antifibrotic and anti-inflammatory properties, attenuating fibroblast proliferation, reducing pro-inflammatory cytokines (e.g., TNF-α, IL-1β), and decreasing extracellular-matrix accumulation in response to growth factors (e.g., TGF-β, PDGF). (2) (3)
What is Pirfenidone used for?
Idiopathic pulmonary fibrosis (IPF)
Pirfenidone is indicated in adults for the treatment of idiopathic pulmonary fibrosis. (1) (2) (3)
Before taking pirfenidone
Do not take / not appropriate for
- Do not take pirfenidone if you have a known hypersensitivity to pirfenidone or any of the excipients. (EU product information (Esbriet SmPC section 4.3); the US prescribing information lists no contraindications) (3)
- Do not take pirfenidone if you have a history of angioedema with previous pirfenidone use. (EU product information (Esbriet SmPC section 4.3); the US prescribing information lists no contraindications) (3)
- Do not take pirfenidone with fluvoxamine, a strong CYP1A2 inhibitor, due to significantly increased exposure to pirfenidone. (EU product information (Esbriet SmPC section 4.3); the US prescribing information lists no contraindications) (3) (2)
- Pirfenidone is not recommended for use in patients with severe hepatic impairment (Child Pugh Class C) or end-stage liver disease. (EU product information (Esbriet SmPC section 4.3); the US prescribing information lists no contraindications) (2) (3)
- Pirfenidone is not recommended for use in patients with severe renal impairment (CrCl <30 mL/min) or end-stage renal disease requiring dialysis. (EU product information (Esbriet SmPC section 4.3); the US prescribing information lists no contraindications) (2) (3)
Tell your clinician about
- Any liver or kidney problems you have or have ever had.
- All prescription and nonprescription medicines, vitamins, and herbal supplements you take. The specialist may need to change doses or monitor you closely.
- If you are pregnant, plan to become pregnant, or are breastfeeding.
- Any use of tobacco products. Cigarette smoking can decrease the medicine's effectiveness; the specialist will advise you to stop smoking before starting and avoid it during treatment.
Pirfenidone dosage and how to take it
- Pirfenidone is taken by mouth, usually with food three times a day, at the same times each day.
- The specialist will start you on a low dose and gradually increase it over a 2-week period to the full maintenance dose of 801 mg three times a day.
- Do not take more than 3 doses per day or more than 2403 mg per day.
- Do not take 2 doses at the same time to make up for a missed dose.
- Swallow tablets whole with water.
- If you experience significant gastrointestinal upset, nausea, or dizziness, remind yourself to take the medicine with food. Do not alter the dose yourself; the specialist may adjust or interrupt the dose temporarily.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3)
Missed dose
If you remember a missed dose, take it as soon as possible with food. However, if it is almost time for the next dose, skip the missed dose and continue the regular schedule. Do not take an extra dose to make up for a missed one. If you miss 14 or more consecutive days of treatment, call the specialist. You will need to restart at the low titration schedule over 2 weeks.
Overdose
There is limited clinical experience with overdose. If more than the prescribed dose may have been taken, contact a poison-control helpline immediately (in the US, 1-800-222-1222). If the person has collapsed, had a seizure, has trouble breathing, or cannot be woken, call emergency services (911 in the US) immediately. Supportive medical care, including monitoring of vital signs and clinical observation, would be provided if needed. (1) (2) (3)
Pirfenidone side effects
Many effects are most noticeable during the first 3 months or upon dose increases. The specialist will monitor you closely and may adjust the dose or advise a temporary interruption to help manage side effects. Do not stop treatment on your own.
Nausea, diarrhoea, dyspepsia, vomitting, abdominal pain, or gastro-oesophageal reflux
What to notice: Gastrointestinal upset, often worse early in treatment. Taking the dose with food may help.
What to do: Tell the treatment team if severe, persistent, or causing weight loss. The specialist may reduce or temporarily interrupt the dose. (2) (3)
Photosensitivity reaction or rash
What to notice: Sunburn-like redness, swelling, blistering, or a rash after minimal sun exposure.
What to do: Avoid sun and sunlamps, wear protective clothing and SPF 50+ sunblock. Tell the treatment team. Dose adjustment or interruption may be needed. (1) (2) (3)
Fatigue, headache, dizziness, insomnia, decreased appetite, or weight loss
What to notice: New or worsening tiredness, light-headedness, trouble sleeping, or noticeable loss of weight.
What to do: Tell the specialist, especially if you feel too dizzy or tired to drive or operate machinery, or if weight loss continues. Do not make dose changes yourself. (1) (2) (3)
Signs of liver injury
What to notice: Unusual tiredness, loss of appetite, pain in the upper right stomach, yellowing of skin or eyes, dark or tea-coloured urine, or unusual bleeding or bruising.
What to do: Contact the specialist immediately or seek urgent medical care. Liver-function monitoring is a required part of treatment. (1) (2) (3)
Severe skin or allergic reaction
What to notice: Flu-like symptoms, spreading rash, blistering, peeling skin, facial or throat swelling, hoarseness, difficulty breathing or swallowing.
What to do: Get emergency medical attention immediately and do not take another dose until a clinician has assessed you. For facial or throat swelling or difficulty breathing, the EU product information says treatment should be discontinued immediately. (1) (2) (3)
Serious warnings
Severe cutaneous adverse reactions (SCAR) — emergency
Symptoms: Widespreaed rash, blistering, target-like skin lesions, skin peeling, fever, facial swelling, or swollen lymph nodes.
Action: Seek emergency care immediately. Do not take another dose until the cause is identified. Let the clinician you see advise on permanent discontinuation. (2) (3)
Drug-induced liver injury — emergency
Symptoms: Severe fatigue, right-upper stomach pain, yellowing of skin/eyes, dark urine, or abnormal bleeding.
Action: Seek emergency assessment and liver testing. In many cases the medicine must be permanently stopped under specialist supervision. (2) (3)
Angioedema or anaphylaxis — emergency
Symptoms: Sweling of the face, lips, tongue, or throat, hoarseness, difficulty breathing, wheezing, or faintness.
Action: Get emergency medical care immediately. Do not take another dose: the EU product information says treatment should be discontinued immediately if signs of angioedema or a severe allergic reaction develop, and pirfenidone must not be used again after angioedema or hypersensitivity caused by it. (2) (3)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Cigarette smoking and strong CYP1A2 inducers | Smoking or other strong inducers (e.g., rifampicin) significantly lower pirfenidone levels and may reduce effectiveness. | Stop smoking before starting and avoid it during treatment. The specialist should manage any necessary co-prescribing. (1) (2) (3) |
| Fluvoxamine and other strong CYP1A2 inhibitors | Fluvoxamine is contraindicated. Strong CYP1A2 inhibitors (e.g., enoxacin) can greatly increase pirfenidone exposure, raising side-effect risk. | Fluvoxamine must be stopped before starting pirfenidone. If another strong CYP1A2 inhibitor cannot be avoided, the specialist will reduce the pirfenidone dose. (2) (3) |
| Ciprofloxacin and other moderate CYP1A2 inhibitors | Ciprofloxacin 750 mg twice daily increases pirfenidone exposure by about 81%. Other moderate inhibitors (e.g., amiodarone, propafenone) may also increase exposure. | The specialist may reduce the pirfenidone dose if ciprofloxacin at 750 mg twice daily is used. Caution is needed with lower ciprofloxacin doses or other moderate CYP1A2 inhibitors. (2) (3) |
| Grapefruit juice | Grapefruit juice can inhibit CYP1A2 and increase pirfenidone exposure. | Avoid drinking grapefruit juice during treatment. (3) |
Special populations
Pregnancy and breastfeeding
Limited human data exist. In high-dose animal studies, gestation prolongation and reduced pup viability were seen. As a precaution, it is preferable to avoid pirfenidone during pregnancy. It is unknown whether pirfenidone passes into human milk; a decision must be made with the specialist whether to discontinue breastfeeding or pirfenidone. (2) (3)
Hepatic impairment
Use with caution in mild (Child Pugh A) to moderate (Child Pugh B) hepatic impairment. Pirfenidone is not recommended in severe hepatic impairment (Child Pugh C) or end-stage liver disease. Close monitoring is required. (2) (3)
Renal impairment
Advice differs between product labels. The US prescribing information says pirfenidone should be used with caution in mild, moderate, or severe (CrCl less than 30 mL/min) renal impairment, and it is not recommended in end-stage renal disease requiring dialysis. The EU product information for Esbriet says it should be used with caution in moderate renal impairment (CrCl 30-50 mL/min) and should not be used in severe renal impairment (CrCl <30 mL/min) or end-stage renal disease requiring dialysis. Your prescriber will check your kidney function against the label that applies where you live. (2) (3)
Older adults (≥65 years)
No overall differences in safety or effectiveness were seen between older and younger patients. No dose adjustment based on age alone is required. (2) (3)
Paediatric patients
Safety and effectiveness in paediatric patients have not been established. There is no relevant use in children for IPF. (2) (3)
Monitoring
Before starting
- Liver function tests (ALT, AST, and bilirubin) must be performed before starting treatment.
- Confirm IPF diagnosis by a specialist experienced in the condition.
- Assess all regular medicines, smoking status, grapefruit juice intake, hepatic and renal function, and pregnancy/breastfeeding status.
During treatment
- Liver function tests should be checked monthly for the first 6 months, then every 3 months, and as clinically indicated.
- The specialist will monitor for gastrointestinal upset, photosensitivity, rash, dizziness, fatigue, weight loss, and signs of liver injury.
- Dose may be adjusted, interrupted, or permanently discontinued based on side effects or liver-enzyme elevations according to strict specialist protocols.
- Weight and hyponatraemia may need periodic monitoring.
Storage
Keep the medicine in the original container, tightly closed, at room temperature away from excess heat and moisture (not in the bathroom). Do not use if the manufacturer's seal is broken or missing when you first receive it. Dispose of unwanted medicine via a medicine take-back programme; do not flush down the toilet. Keep out of the reach of children.
Professional information
Clinician-facing context only. Use the current local indication, dosing tables, hepatic/renal adjustment criteria, and the exact product information.
US (FDA) / EU (EMA)
Indication: Idiopathic pulmonary fibrosis
Dose summary: Titrate from 267 mg three times daily (Days 1-7), to 534 mg three times daily (Days 8-14), to maintenance 801 mg three times daily (2403 mg/day) taken with food. Dose must be reduced with strong or moderate CYP1A2 inhibitors (e.g., fluvoxamine: contraindicated; enoxacin: 267 mg three times daily; ciprofloxacin 750 mg bid: 534 mg three times daily). For liver enzyme elevations, follow the product-specific interruption/permanent-discontinuation protocol.
Renal context: Labels differ. US PI: use with caution in mild (CrCl 50-80), moderate (30-50) or severe (<30 mL/min) renal impairment; not recommended in ESRD requiring dialysis. EU SmPC (Esbriet): no adjustment in mild; caution in moderate (CrCl 30-50 mL/min); contraindicated in severe renal impairment (CrCl <30 mL/min) or ESRD requiring dialysis. (2) (3)
Hepatic guidance
Contraindicated in severe hepatic impairment (Child Pugh C) per EU label; not recommended per US label. Use with caution in mild-to-moderate impairment; exposure increased by 60% in moderate impairment.
Overdose note
Supportive care, vital-sign monitoring, and clinical observation. No specific antidote. (2) (3)
Frequently asked questions
How long do I take pirfenidone?
Your specialist will determine how long you should continue based on your response and tolerability. Do not stop on your own. (1) (2)
What happens if I forget several days of doses?
If you miss 14 or more consecutive days, contact your specialist. You will need to restart at the low titration dose and build up again over 2 weeks. Do not restart the full dose yourself. (1) (2) (3)
Can I sunbathe or use a tanning bed while taking pirfenidone?
No. You must avoid or minimise direct sunlight (including sunlamps and tanning beds), wear protective clothing, and use a daily sunblock with SPF 50 or higher. Pirfenidone makes your skin more sensitive to sunlight, and severe burn-like reactions can occur. (1) (3)
What is the mechanism of action of pirfenidone?
The mechanism of action in IPF has not been fully established. Data suggest pirfenidone exerts both antifibrotic and anti-inflammatory properties, attenuating fibroblast proliferation, reducing pro-inflammatory cytokines (e.g., TNF-α, IL-1β), and decreasing extracellular-matrix accumulation in response to growth factors (e.g., TGF-β, PDGF). (2) (3)
References
- Pirfenidone: MedlinePlus Drug InformationMedlinePlus, U.S. National Library of Medicine · United States · accessed 2026-10-19 · source 1
- PIRFENIDONE tablet, film coatedU.S. National Library of Medicine, DailyMed · United States · accessed 2026-10-19 · source 2
- Esbriet (pirfenidone) EPAR Product InformationEuropean Medicines Agency · European Union · accessed 2026-10-19 · source 3
- Pirfenidone UK SmPC — RESOURCE UNRESOLVEDMedicines and Healthcare products Regulatory Agency · United Kingdom · accessed 2026-10-19 · source 4
Brand names by country
Single-ingredient pirfenidone names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
View brands in additional countries.
European Union
Esbriet