<prompt> Which of the following drugs is useful in the treatment of infection by mycobacterium avium complexIsoniazidClarithromycinCycloserineRifamipicin  <response>: Refer KDT 6e p 750 Treatment of MAC infection is REC RifabutinEthambutolClarithromycin Claruthromycin alone used for the prophylaxis of MAC infection in HIV positive patients. Azithromycin can also be used in place for Clarithromycin 