• Viagra is used to treat erectile dysfunction in men. It works by helping the blood flow into the penis to achieve and maintain an erection.

How should you take this medication?

• This medication is taken by mouth as needed, 30 minutes to 1 hour before sexual activity.  It continues to work for up to 4 hours, although its action is usually less after 2 hours. Do not take Viagra more than once per day.

General Precautions with Viagra

• Viagra may cause dizziness, blurred vision, fainting, or lightheadedness. Do not drive, operate machinery, or do anything else that could be dangerous until you know how you react to Viagra .
   
• Do not use Viagra if your doctor has advised you to avoid sexual activity because of heart problems. Do not take Viagra if you are also using a nitrate drug for chest pain or heart problems.

• This medicine does not protect you against sexually transmitted diseases. Use safe sex practices such as latex condoms.

What are the possible side effects of Viagra?

• Check with your doctor if any of these side effects persist or become bothersome: back pain, diarrhea, dizziness, flushing, headache, bloody nose, indigestion, joint pain, stomach upset, vision changes.