Important information about Viagra

Important information about Viagra

                         

You should not use Viagra if you are allergic to sildenafil.

Do not take Viagra if you are also using a nitrate drug for chest pain or heart problems. This includes nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate. Nitrates are also found in some recreational drugs such as amyl nitrate or nitrite ("poppers"). Taking Viagra with a nitrate medicine can cause a sudden and serious decrease in blood pressure.

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Contact your doctor or seek emergency medical attention if your erection is painful or lasts longer than 4 hours. A prolonged erection (priapism) can damage the penis.

Stop using this medicine and get emergency medical help if you have sudden vision loss.

Before taking Viagra

You should not use Viagra if you are allergic to sildenafil.

Do not take Viagra if you are also using a nitrate drug for chest pain or heart problems. This includes nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate. Nitrates are also found in some recreational drugs such as amyl nitrate or nitrite ("poppers"). Taking Viagra with a nitrate medicine can cause a sudden and serious decrease in blood pressure.

To make sure Viagra is safe for you, tell your doctor about your other medical conditions, especially:

• heart disease or heart rhythm problems, coronary artery disease;
• a recent history (in the past 6 months) of a heart attack, stroke, or congestive heart failure;
• high or low blood pressure;
• liver or 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.

Viagra can decrease blood flow to the optic nerve of the eye, causing sudden vision loss. This has occurred in a small number of people taking Viagra, most of whom also had heart disease, diabetes, high blood pressure, high cholesterol, or certain pre-existing eye problems, and in those who smoke or are over 50 years old. It is not clear whether Viagra is the actual cause of vision loss. Stop using Viagra and get emergency medical help if you have sudden vision loss.

FDA pregnancy category B: This medication is not expected to be harmful to an unborn baby. Do not use Viagra without telling your doctor if you are pregnant or plan to become pregnant during treatment.

See also: Viagra pregnancy and breastfeeding warnings (in more detail)

It is not known whether sildenafil passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Do not give this medication to anyone under 18 years old without medical advice.

How should I take Viagra?

Take Viagra exactly as prescribed by your doctor. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

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 this medicine 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 at room temperature away from moisture and heat.

See also: Viagra dosage (in more detail)

What happens if I miss a dose?

Since Viagra is used as needed, you are not likely to miss a dose. Do not take extra medicine to make up a missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Viagra?

Grapefruit and grapefruit juice may interact with Viagra and lead to unwanted side effects. Avoid the use of grapefruit products while taking this medicine.

Drinking alcohol can increase certain side effects of Viagra.

Avoid using any other medicines to treat impotence, such as alprostadil or yohimbine, without first talking to your doctor.

See also: Viagra and alcohol (in more detail)

Viagra side effects

Get emergency medical help if you have any of these signs of an allergic reaction to Viagra: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Contact your doctor or seek emergency medical attention if your erection is painful or lasts longer than 4 hours. A prolonged erection (priapism) can damage the penis.

Stop using Viagra and call your doctor at once if you have:

• vision changes or sudden vision loss;
• ringing in your ears, or sudden hearing loss;
• chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling;
• irregular heartbeat;
• swelling in your hands, ankles, or feet;
• shortness of breath; or
• a light-headed feeling, like you might pass out.

Common Viagra side effects may include:

• warmth or redness in your face, neck, or chest;
• headache;
• upset stomach; or
• diarrhea.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Viagra side effects (in more detail)

What other drugs will affect Viagra?

Do not take Viagra with similar medications such as avanafil (Stendra), tadalafil (Cialis) or vardenafil (Levitra). Tell your doctor about all other medications you use for erectile dysfunction.

Tell your doctor about all medicines you use, and those you start or stop using during your treatment, especially:

• cimetidine;
• bosentan;
• imatinib;
• nefazodone;
• St. John's wort;
• an antibiotic--clarithromycin, erythromycin, telithromycin;
• antifungal medication--fluconazole, itraconazole, ketoconazole, miconazole, posaconazole, voriconazole;
• heart or blood pressure medication--amlodipine, amiodarone, nicardipine, quinidine;
• hepatitis C medications--boceprevir, telaprevir;
• HIV/AIDS medication--atazanavir, delavirdine, efavirenz, fosamprenavir, indinavir, nelfinavir, nevirapine, ritonavir, saquinavir;
• seizure medication--carbamazepine, fosphenytoin, oxcarbazepine, phenobarbital, phenytoin, primidone; or
• tuberculosis medication--isoniazid, rifabutin, rifampin, rifapentine.

This list is not complete. Other drugs may interact with sildenafil, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.