Proof-of-concept to Evaluate the Efficacy and Safety of Prednisone in Idiosyncratic Hepatotoxicity

Inclusion Criteria: 1. Female and male patients, aged ≥ 18 years. 2. Patients who have been diagnosed with DILI by the expert committee. 3. Patients with moderate to severe DILI (elevations of ALT or AST ≥ 5 times the Upper Limit of Normal (ULN) and serum TBL ≥ 2.5 mg/dL). 4. Patients who do not show a 15% reduction in ALT values or TBL continues to increase 5-10 days after liver damage recognition despite the withdrawal of the culprit drug. Exclusion Criteria: 1. No clear DILI diagnosis after an expert committee DILI assessment. 2. DILI due to immune-checkpoint inhibitors. 3. Presence of active infection as evidenced by positive urine or blood culture. 4. Acute liver failure (international normalized ratio (INR) \> 1.5 and hepatic encephalopathy). 5. Model for End-Stage Liver Disease (MELD) ≥ 30. 6. Known hypersensitivity to prednisone or placebo components. 7. Pregnant or nursing mothers. 8. Co-existing infection with hepatitis C, hepatitis B, or human immunodeficiency virus (HIV). 9. Patients already receiving systemic steroids or other immunosuppressants. 10. Inability to provide informed consent. 11. Presence of clinically significant comorbid illnesses (by clinician's criteria) that might impede the completion of the study.