By controlling the enzyme phosphodiesterase, sildenafil helps to maintain an erection that is produced when the penis is stroked. Without physical action to the penis, such as that occurring during sexual intercourse, sildenafil will not work to cause an erection.

This medicine is available only with your doctor's prescription, in the following dosage form(s):

Oral
• Tablets

Proper Use of This Medicine
Special patient directions come with sildenafil. Read the directions carefully before using the medicine.

This medicine usually begins to work within 30 minutes after taking it. It continues to work for up to 4 hours, although its action is usually less after 2 hours.

Dosing - The dose of sildenafil will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of sildenafil. If your dose is different, do not change it unless your doctor tells you to do so.

• For oral dosage form (tablets):
  • For treatment of erectile dysfunction:
    • Adults up to 65 years of age50 mg as a single dose no more than once a day, 1 hour before sexual intercourse. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. If needed, your doctor may increase your daily dose to 100 mg or decrease your daily dose to 25 mg.
    • Adults 65 years of age and older25 mg as a single dose no more than once a day, 1 hour before sexual intercourse. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. If needed, your doctor may increase your daily dose.
    • If you are taking protease inhibitors, such as for the treatment of HIV, your doctor may recommend a 25 mg dose and may limit you to a maximum single dose of 25 mg of Viagra in a 48 hour period
  Storage - To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Keep the medicine from freezing. Do not refrigerate.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.