GPT and tuberculosis: Most international guidelines1,3,27,41 follow the recommendation of reintroducing TB drugs after transaminase levels (especially alanine transaminase [ALT]) decrease to less than two times the ULN, bilirubin levels return to normal (for adults over 18 years old, normal total bilirubin is less than 1.2 mg/dL [20.5 micromol/L] of blood; in those aged <18 years, the upper limit is 1 mg/dL) and the person has no symptoms of hepatotoxicity.