Abstract: Objective To explore the mechanism and treatment of muscle ache caused by pirfenidone. Methods The diagnosis and treatment process of one patient with muscle ache caused by pirfenidone were analyzed. Based on literature review, the causal relationships between pirfenidone and muscle ache, the mechanism of its occurrence and the focus of treatment were outlined. Results and Conclusion The symptoms of muscle ache caused by pirfenidone are related to the increased dose of pirfenidone, which can remind clinicians to pay attention to the new pharmaceutical care points in the process of treatment with pirfenidone. Doctors can take such active measures as reducing the dosage, stopping the medication or adjusting the treatment plan according to the condition of patients.

Key words: pirfenidone, muscle ache, adverse drug reaction