This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Anti-tubercular drug not given in liver disease is ? 
Select and explain. 
A. Isoniazid, B. Ethambutol, C. Pyrazinamide, D. Rifampicin
C: Pyrazinamide
Answer: C: Pyrazinamide 
Explanation: Ans. is 'c' i.e., Pyrizinamide o Among the given options, only ethambutol is safe in liver disease. Other three drugs cause hepatotoxicity and should be avoided. o However, if the question is repeated as such, best answer is pyrazinamide because of following statement of Harrison-"In case of presence of hepatic risk factors or if during treatment hepatitis develops in a patient, one might rechallange the patient with rifampicin and isoniazid but pyrizinamide is never given".