All of the following cause inhibition of CYP3A except: (A) Saquinavir, (B) Ritonavir, (C) Itraconazole, (D) Erythromycin
Answer is A. All the drugs given in the option are microsomal enzyme inhibitors .Among protease inhibitor,ritonavir the strongest inhibitor of CYP3A4 enzymes whereas saquanivir is the weakest