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Antifibrotic Pregnancy: Avoid — insufficient data; mandatory contraception advised

Pirfenidone

Brand names: Esbriet

Adult dose

Dose: Week 1–2: 267 mg TDS. Week 3–4: 534 mg TDS. Week 5+: 801 mg TDS (target dose)
Route: Oral (with food)
Frequency: Three times daily
Max: 2403 mg/day (801 mg TDS)
For mild-moderate IPF. Dose escalation over 4 weeks to reduce GI and photosensitivity side effects. Take with food. Apply high SPF sunscreen and protective clothing.

Paediatric dose

Route: N/A
Frequency: N/A
Max: Not licensed in children
No established paediatric dosing

Dose adjustments

Renal

Caution in moderate-severe renal impairment; avoid in end-stage renal disease

Hepatic

Contraindicated in severe hepatic impairment. Caution in moderate impairment (LFTs carefully monitored).

Clinical pearls

  • ASCEND trial: reduces FVC decline and all-cause mortality in IPF
  • Photosensitivity is significant — SPF50+ sunscreen, protective clothing, and avoid sun exposure are mandatory
  • Smoking induces CYP1A2 and reduces pirfenidone efficacy by 50% — smoking cessation is essential
  • LFTs must be monitored — dose reduction or interruption may be needed if elevated

Contraindications

  • Severe hepatic impairment
  • Concomitant fluvoxamine (potent CYP1A2 inhibitor)

Side effects

  • Photosensitivity (most important — advise SPF50+ sunscreen)
  • Nausea (36%)
  • Fatigue
  • Dizziness
  • Diarrhoea
  • Dyspepsia
  • LFT elevation

Interactions

  • Fluvoxamine — contraindicated (CYP1A2 inhibitor — 6-fold increase in pirfenidone exposure)
  • Ciprofloxacin — increased pirfenidone exposure
  • Smoking — reduces pirfenidone levels by 50% via CYP1A2 induction; advise smoking cessation
  • Omeprazole — mild increase in pirfenidone exposure

Monitoring

  • LFTs monthly for first 6 months, then 3-monthly
  • FVC every 6 months
  • Photosensitivity and skin reactions
  • Weight and nutritional status

Reference: BNFc; ASCEND Trial (King et al, NEJM 2014); BNF; NICE TA379. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Pathways