The mechanism of action of pirfenidone in the treatment of IPF has not been established.

Pirfenidone capsules are indicated for the treatment of idiopathic pulmonary fibrosis (IPF).

The recommended daily maintenance dosage of pirfenidone capsule is 801 mg three times daily for a total of 2,403 mg/day. Doses should be taken with food at the same time each day.

Upon initiation of treatment, titrate to the full dosage of 2,403 mg/day over a 14-day period as follows:

The most common (> 3%) adverse reactions leading to dosage reduction or interruption were rash, nausea, diarrhea, and photosensitivity reaction.

None

Cases of drug-induced liver injury (DILI) have been observed with pirfenidone. Patients treated with pirfenidone 2,403 mg/day in the three Phase 3 studies had a higher incidence of photosensitivity reactions (9%) compared with patients treated with placebo (1%). Severe cutaneous adverse reactions (SCAR), including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS), have been reported in association with the use of pirfenidone. gastrointestinal events of nausea, diarrhea, dyspepsia, vomiting, gastro-esophageal reflux disease, and abdominal pain were more frequently reported by patients in the pirfenidone treatment