The contraindications for pirfenidone mainly include severe liver and kidney dysfunction, pregnant women, and patients with specific physiological conditions, and the risk benefit ratio needs to be strictly evaluated. End stage renal disease patients with Child Pugh C liver function and requiring dialysis are contraindicated, and pregnant women should avoid using it due to lack of safety data.

Taboos for patients with liver dysfunction

(1) Child Pugh C grade: Pirfenidone should not be used in patients with severe liver dysfunction, as its metabolism mainly relies on the liver and may exacerbate liver damage.

(2) Child Pugh A/B grade: Patients with mild to moderate liver damage should use with caution. The initial dose should be halved and ALT/AST should be closely monitored. If symptoms of liver toxicity occur, the medication should be stopped immediately.

(3) Monitoring requirements: Liver function must be evaluated before treatment, and transaminase testing should be conducted monthly during medication until the dose stabilizes, then changed to once every 3 months.

Taboos for patients with renal insufficiency

(1) End stage renal disease: Dialysis patients are not recommended to use it due to lack of pharmacokinetic data and inability to clear drugs through dialysis.

(2) Mild to moderate kidney damage: Patients with CrCl30-80mL/min should use it with caution, adjust the dosage, and monitor creatinine and electrolyte levels.

(3) Risk Warning: Renal insufficiency may increase the risk of drug accumulation, especially in elderly patients who are more prone to adverse reactions such as hyperkalemia.

3 Contraindications during pregnancy and lactation

(1) Pregnant women prohibited: Animal studies have shown embryotoxicity, human data is insufficient, and use during pregnancy may increase the risk of miscarriage or fetal malformation.

(2) Caution during lactation: It is unknown whether the medication has entered breast milk. If necessary, breastfeeding should be suspended and the necessity of treatment should be weighed.

(3) Contraceptive requirements: Women of childbearing age should take effective contraceptive measures during medication and one month after discontinuation.

4 Other taboo groups

(1) Children under 18 years old: Safety and efficacy have not been established, and it is not recommended for pediatric patients.

(2) Smokers: Tobacco accelerates drug metabolism and reduces efficacy. Smoking should be stopped before medication and continued until the end of treatment.

(3) Allergy history: Individuals allergic to pirfenidone or capsule ingredients are prohibited from using it.