During the treatment of pirfenidone, attention should be paid to the three major risks of photosensitivity, hepatotoxicity, and gastrointestinal intolerance. The photosensitive reaction requires strict sun protection, and liver toxicity requires regular monitoring of liver function. Gastrointestinal symptoms often occur in the early stages of medication and can be relieved by taking with meals and adjusting the dosage.

1. Protection against photosensitive reactions

The incidence of photosensitive reactions during treatment with pirfenidone can reach 9%, and the following protective measures should be taken:

(1) Avoid strong light exposure: Reduce going out from 10am to 3pm, and avoid using fluorescent lamps and tanning beds. (2) Physical protection: Wear protective equipment such as long sleeved clothing and wide brimmed hats to reduce direct skin exposure. (3) Chemical protection: Use SPF50+sunscreen daily, apply 30 minutes before going out and reapply every 2 hours. (4) Symptom monitoring: If severe sunburn, skin erythema, or blisters occur, seek medical attention immediately and reduce or discontinue medication if necessary.

2 Hepatotoxicity Management

Pirfenidone may cause drug-induced liver injury and requires standardized monitoring and management:

(1) Monitoring frequency: ALT/AST/bilirubin testing is conducted monthly before treatment and for the first 6 months, followed by every 3 months thereafter. (2) Symptom recognition: If jaundice, fatigue, upper right abdominal pain or darkened urine color occur, liver function should be checked immediately. (3) Dose adjustment: ALT/AST>3 times ULN should be reduced, and>5 times ULN or accompanied by hyperbilirubinemia should be permanently discontinued. (4) Taboo population: Children Pugh C grade liver dysfunction patients are contraindicated.

3 Gastrointestinal intolerance coping strategies

The incidence of gastrointestinal reactions is relatively high and can be alleviated through the following methods:

(1) Medication method: Strictly take with meals, take small amounts of water in divided doses. (2) Dietary adjustment: Avoid spicy and greasy foods, and take ginger sugar to relieve nausea. (3) Symptom management: Diarrhea can be treated with oral rehydration salts, and continuous vomiting requires medical attention for rehydration. (4) Dose adjustment: Severe gastrointestinal reactions can be temporarily reduced to 534mg three times a day, and gradually recovered after symptom relief.