Pyrazinamide related prolonged drug-induced liver injury: A case report

Rationale: Drug induced liver injury (DILI) is a common side effect causing treatment discontinuation during tuberculosis (TB) treatment, and pyrazinamide (PZA) usually leads to a delayed and prolonged abnormal liver function of the 4 standard anti-tuberculosis regimens. However, a prolonged hepatitis lasting more than 4 months is rarely reported. Patient concerns: A 78-year-old man presented with general weakness and poor appetite on his seventh week of anti-TB treatment for tuberculosis lymphadenitis. Diagnosis: Drug induced liver injury, PZA-related. NAT2 slow acetylator phenotype was accidentally found during workup of DILI. Intervention: A liver biopsy was performed and PZA-related DILI was suspected. All anti-TB medications were therefore discontinued. Outcome: After withholding all anti-TB medications for 4 months, the elevations of aminotransferases and hyperbilirubinemia completely resolved. Anti-TB therapy was switched to ethambutol and levofloxacin for 15 months without adverse events. Long-term ultrasound follow-up was performed and cervical lymphadenopathy completely resolved. Conclusion: Our patient presents with PZA related prolonged DILI resolved after drug discontinuation for 4 months. NAT2 slow acetylator phenotype may be related to this condition through unknown mechanisms.