Viagra

sildenafil

Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil treats erectile dysfunction by increasing blood flow to the penis during sexual stimulation. This increased blood flow can cause an erection.

What is Viagra?

Viagra is in a class of medications called phosphodiesterase (PDE) inhibitors. Viagra works by dilating the blood vessels in the penis allowing more blood to flow in. As the result, the patient is able to achieve a stable erection for long enough to compete sexual intercourse.

Before taking Viagra

Before taking Viagra, tell your doctor if you are allergic to any drugs, or if you have:

• heart disease or heart rhythm problems;
• a recent history (in the past 6 months) of a heart attack, stroke, or heart rhythm disorder;
• congestive heart failure;
• high or low blood pressure;
• coronary artery disease;
• liver disease;
• kidney disease;
• a blood cell disorder such as sickle cell anemia, multiple myeloma, or leukemia;
• a bleeding disorder such as hemophilia;
• a stomach ulcer;
• retinitis pigmentosa (an inherited condition of the eye);
• a physical deformity of the penis (such as Peyronie's disease); or
• if you have been told you should not have sexual intercourse for health reasons.

If you have any of these conditions, you may need a dose adjustment or special tests to safely take this medicine.

How should I take Viagra?

Take Viagra exactly as it was prescribed for you. Do not take it in larger doses or for longer than recommended by your doctor. Follow the directions on your prescription label. Viagra is usually taken only when needed, 30 minutes to 1 hour before sexual activity. You may take it up to 4 hours before sexual activity. Do not take Viagra more than once per day. Viagra can help you have an erection when sexual stimulation occurs. An erection will not occur just by taking a pill. Follow your doctor's instructions.

During sexual activity, if you become dizzy or nauseated, or have pain, numbness, or tingling in your chest, arms, neck, or jaw, stop and call your doctor right away. You could be having a serious side effect of Viagra. Store this medication at room temperature away from moisture and heat.

Viagra side effects

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Viagra. Side effects may include: abnormal vision (color tinge, blurring, sensitivity to light), acid indigestion, diarrhea, flushing, headache, nasal congestion, urinary tract infection.

Precautions

If you take Viagra and develop cardiac symptoms (for example, dizziness, nausea, and chest pain) during sexual activity, do not continue. Alert your doctor to the problem as soon as possible. If you have a condition that might result in long-lasting erections, such as sickle cell anemia, multiple myeloma (a disease of the bone marrow), or leukemia, use Viagra with caution. Also use cautiously if you have a genital problem or deformity such as Peyronie's disease. If an erection lasts more than 4 hours, seek treatment immediately. Permanent damage and impotence could result.

If you have a bleeding disorder, a stomach ulcer, or the inherited eye condition known as retinitis pigmentosa, use Viagra with caution. Its safety under these circumstances has not yet been studied. If you experience a loss of vision in one or both eyes, stop using Viagra and seek medical attention immediately.

Drug interactions

If Viagra is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Viagra with the following: other impotence remedies including Caverject and Muse, alpha-blockers such as doxazosin (Cardura), amlodipine (Norvasc), cimetidine (Tagamet), erythromycin (E-Mycin, Ery-Tab, PCE), itraconazole (Sporanox), ketoconazole (Nizoral), nitrates such as Isordil, Nitro-Bid, and Nitro-Dur, rifampin (Rifadin, Rimactane), ritonavir (Norvir), saquinavir (Fortovase, Invirase).

Overdose

No overdose of Viagra has been reported. However, any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.

Notes

This information is a summary only. It does not contain all information about Viagra. If you have any other questions about Viagra, please talk with your doctor, pharmacist, or other health care provider.