Pirfenidone Disease Interactions

Increases in ALT and AST (>3 x ULN) with or without concomitant elevations in bilirubin, have been reported in patients treated with pirfenidone. These findings were reversible with dose modification or treatment discontinuation. Conduct liver tests prior to therapy initiation in all patients, then monthly for the first 6 months and every 3 months thereafter. Dose modification or interruption may be necessary for liver enzyme elevations. Pirfenidone should be used with caution in patients with mild to moderate hepatic impairment, monitoring adverse reactions. The safety and efficacy of pirfenidone has not been studied in patients with severe hepatic impairment, and is not recommended for use in these patients.

Pirfenidone should be used with caution in patients with mild, moderate, or severe renal impairment, monitoring for adverse reactions and considering dosage modifications or discontinuation as needed. The safety and efficacy of pirfenidone has not been studied in patients with end-stage renal disease requiring dialysis, so its use is not recommended in these patients.

Smoking causes decreased exposure to pirfenidone, which may alter its efficacy. Patients should be instructed to stop smoking prior to treatment, and to avoid smoking while taking pirfenidone.