<prompt> Which of the following is least likely to cause interstitial nephritis on chronic use-MethicillinCephalothinHeparinAmpicillin  <response>: Ans. is c i.e., Heparin Drug causing interstitial nephritis o Cephalosporine o Allopurinol o Phenindione o Thiazides o Rifampcin o Penicillins esp. methicillin o Ciprofloxacin o Sulphonamides o NSAIDS o Furosemide 