Background and aims: Hepatotoxicity is a major side-effect of antitubercular drugs (ATD). As these drugs are metabolized in the liver, there is a theoretical risk of increased hepatotoxicity in patients with underlying chronic liver disease (CLD). Ofloxacin has antitubercular activity and has exclusive renal clearance. The aim was to study the efficacy and safety of an ofloxacin-based antitubercular regimen for treating tuberculosis in patients with underlying CLD.
Methods: Thirty-one cases were randomly assigned to two drug regimens using WHO dosage schedules: (i) regimen A (n = 15): isoniazid, rifampicin and ethambutol for 2 months, followed by isoniazid and rifampicin for a further 7 months; and (ii) regimen B (n = 16): isoniazid, pyrazinamide, ethambutol and ofloxacin for 2 months, followed by isoniazid, ethambutol and ofloxacin for a further 10 months. Hepatotoxicity was diagnosed if alanine aminotransferase/aspartate aminotransferase increased > fivefold from the baseline or to > 400 IU/L, or if bilirubin increased by > 2.5 mg/dL from the baseline.
Results: The response to ATD was achieved in all the patients who completed the therapy. Four (26.6%) patients on regimen A developed hepatotoxicity as compared to none on regimen B (P = 0.043). None of these patients could be restarted on ATD using the same regimen A because of the persistently deranged liver functions.
Conclusions: In patients with tuberculosis who have underlying CLD: (i) an ofloxacin-based antitubercular regimen without rifampicin is as effective as a rifampicin-based regimen; and (ii) a combination of isoniazid with rifampicin is more hepatotoxic than a combination with ofloxacin and pyrazinamide.