Pirfenidone (Esbriet) is a pyridone drug used for the treatment of idiopathic pulmonary fibrosis (IPF). It slows down disease progression by inhibiting the fibrosis process. Its efficacy has been verified in multiple clinical trials, but strict adherence to medication guidelines is required to enhance therapeutic effects and reduce adverse reactions.

Precautions for the Use of Pirfenidone (Esbriet)

Initial Dose Titration Regimen

To avoid adverse reactions caused by a sudden high dose, the dose should be gradually increased within 14 days.

Days 1-7: 1 capsule (267mg per capsule), 3 times a day (total 801mg per day).

Days 8-14: 2 capsules, 3 times a day (total 1602mg per day).

From Day 15 onwards: 3 capsules, 3 times a day (maintenance dose of 2403mg per day).

Administration with Food

Taking pirfenidone with food can reduce gastrointestinal reactions such as nausea and dizziness.

Drug Interactions

Strong CYP1A2 inhibitors (e.g., fluvoxamine): Contraindicated, or the dose should be reduced to 1 capsule per dose, 3 times a day.

Moderate CYP1A2 inhibitors (e.g., ciprofloxacin): The dose should be reduced to 2 capsules per dose, 3 times a day.

Lifestyle Adjustments

Sun Protection Measures: The risk of photosensitivity reactions increases after taking the drug (incidence rate: 9% vs. 1% with placebo). It is necessary to use sunscreen with SPF 50+, wear sun-protective clothing, and avoid direct sunlight.

Smoking Cessation: Smoking can reduce the drug exposure, which may affect the therapeutic efficacy.

Medication Monitoring for Pirfenidone (Esbriet)

Liver Function Monitoring

Baseline Examination: Levels of alanine transaminase (ALT), aspartate transaminase (AST), and bilirubin must be tested before starting the medication.

Follow-up Frequency: Re-examination once a month for the first 6 months; re-examination once every 3 months after 6 months.

Management of Abnormalities

If ALT/AST > 3× upper limit of normal (ULN) accompanied by symptoms or hyperbilirubinemia: Permanent discontinuation of the drug is required.

If ALT/AST > 5× ULN: Immediate discontinuation of the drug and permanent prohibition of re-administration.

Side Effect Monitoring

Common Symptoms: Nausea (36%), diarrhea (26%), rash (30%), etc.

Management Principles: If symptoms persist or worsen, temporary dose reduction or treatment interruption is necessary until the symptoms are relieved.

Monitoring in Special Populations

Patients with mild to moderate liver dysfunction (Child-Pugh Class A/B) or renal dysfunction (creatinine clearance [CLcr] 30-80 mL/min) need close monitoring of adverse reactions, and dose adjustment should be made if necessary.

Elderly Patients: No dose adjustment is required, but attention should be paid to the risk of combined medication.