Although not all of these side effects may occur, if they do occur they may need medical attention. Your doctor may adjust your dose if needed. Small case studies in pregnant women with PAH indicate a low risk of harm, though caution is warranted. Make sure you tell your doctor if you have any other medical problems, especially: Abnormal penis, including a curved penis or birth defects of the penis—Chance of problems occurring may be increased and this medicine should be used with caution in these patients. However the dose is usually not more than 40 mg 3 times a day. · Viagra comes as an oral tablet that contains the active drug sildenafil. Sildenafil is also available in generic form. Viagra is classified as a phosphodiesterase type 5 (PDE5) inhibitor. For oral dosage forms (suspension or tablets): Adults—20 milligrams (mg) 3 times a day. Your doctor may adjust your dose as needed and tolerated. However, the dose is usually not more than 80 mg 3 times a day. Children 1 year of age and older weighing 45 kilograms (kg) or more—20 mg 3 times a day. To find out what the average cost of Viagra tablets will be for you, talk with your doctor, pharmacist, or insurance provider. Visit this page to access Optum Perks .