What is the recommended dosage of pirfenidone (Idiopathic Pulmonary Fibrosis (IPF) treatment)?

Pirfenidone Dosage for Idiopathic Pulmonary Fibrosis

The recommended daily maintenance dosage of pirfenidone for IPF is 801 mg three times daily (2,403 mg/day) taken with food, with a mandatory 14-day titration period to minimize side effects. 1

Dosage Titration Schedule

Pirfenidone requires a specific titration schedule to minimize adverse effects:

Days	Dosage
Days 1-7	267 mg three times daily (801 mg/day)
Days 8-14	534 mg three times daily (1,602 mg/day)
Days 15 onward	801 mg three times daily (2,403 mg/day)

2, 1

Administration Guidelines

• Take pirfenidone with food at the same time each day to reduce gastrointestinal side effects 1
• Do not take 2 doses at the same time to make up for a missed dose 1
• Do not take more than 3 doses per day 1
• Taking pirfenidone during a substantial meal can help mitigate gastrointestinal adverse events 3

Dosage Modifications

Treatment Interruptions

• If treatment is interrupted for ≥14 days: Re-initiate with the 2-week titration regimen 1
• If treatment is interrupted for <14 days: Resume the previous dosage 1

Adverse Reactions

• For significant adverse reactions (gastrointestinal, photosensitivity, rash): Consider temporary dosage reductions or interruptions 1
• For severe cutaneous adverse reactions (SCAR): Permanently discontinue pirfenidone 1

Liver Enzyme Elevations

• ALT/AST >3 but ≤5 × ULN without symptoms: May maintain full dose, reduce, or interrupt treatment 1
• ALT/AST >3 but ≤5 × ULN with symptoms or hyperbilirubinemia: Permanently discontinue pirfenidone 1
• ALT/AST >5 × ULN: Permanently discontinue pirfenidone 1

Drug Interactions

• With strong CYP1A2 inhibitors (e.g., fluvoxamine): Reduce to 267 mg three times daily (801 mg/day) 1
• With moderate CYP1A2 inhibitors (e.g., ciprofloxacin 750 mg twice daily): Reduce to 534 mg three times daily (1,602 mg/day) 1

Monitoring Requirements

• Conduct liver function tests prior to initiating treatment 1
• Monitor liver function tests monthly for the first 6 months, then every 3 months 2
• Perform pulmonary function tests every 3-6 months to assess treatment response 2

Clinical Efficacy

Pirfenidone has demonstrated efficacy in slowing disease progression in IPF:

• Reduces decline in forced vital capacity (FVC) 4, 5
• Reduces risk of disease progression by 30% (HR 0.70,95% CI 0.56–0.88) 4
• May reduce IPF-related mortality (HR 0.48,95% CI 0.24–0.95) 4

Common Adverse Effects

• Gastrointestinal: Nausea, vomiting, diarrhea, dyspepsia, abdominal pain 1
• Skin-related: Photosensitivity, rash 1
• Other: Fatigue, headache, decreased appetite, dizziness, weight loss 1

Important Precautions

• Avoid sun exposure and use sunscreen due to photosensitivity risk 2, 3
• Discontinue smoking prior to and during treatment 2
• Avoid concomitant use of fluvoxamine (contraindicated) 1
• Monitor for severe cutaneous adverse reactions which require permanent discontinuation 1

Alternative Titration Considerations

In clinical practice, pulmonologists sometimes implement alternative titration schedules for patients experiencing significant gastrointestinal intolerance, with extended schedules up to 4-8 weeks being reported to help patients achieve the full maintenance dose 3.