<prompt> Which of the following anti-tubercular drug is least hepatotoxic?RifampicinPyrazinamideEthambutolINH  <response>: Ethambutol among the given options is the least hepatotoxic antitubercular drug. Ethambutol side-effect includes Dose dependent adverse effect Red green colour blindness optic neuritis which is initially reversible but later becomes irreversible. Therefore it is avoided in children 6yr. 