Children younger than 1 year of age—Use and dose must be determined by your doctor. If you see air bubbles in the syringe, repeat the steps. These include itraconazole Sporanox, Tolsura , ketoconazole Extina, Ketozole, others and ritonavir Norvir. Remove the cap by pushing it down and twisting it counter-clockwise. Adults 65 years of age and older—25 mg as a single dose no more than once a day, 1 hour before sexual intercourse. You can take it in a small dose daily or in a larger dose as needed.As a walk-in clinic, we treat patients on a first-come, first-served basis. Once you register, the kiosk will display your approximate wait time. You can be sure you get the same . For oral dosage form (tablets): Adults up to 65 years of age—50 milligrams (mg) as a single dose no more than once a day, 1 hour before sexual intercourse. Alternatively, the . These lists contain up to 10 of the most common mild side effects that can occur with Viagra, with Levitra, or with both drugs (when taken individually). Can occur with Viagra: .