More robust CYP3A4 inhibitors like ketoconazole or itraconazole may be expected to acquire increased effects than viewed with saquinavir. A commencing dose of 25 mg of VIAGRA should be viewed as in individuals taking erythromycin or potent CYP3A4 inhibitors (such as saquinavir, ketoconazole, itraconazole) [see DOSAGE AND ADMINISTRATION, Medical PHA