What is sildenafil?

Sildenafil relaxes muscles and increases blood flow to particular areas of the body.

Sildenafil under the name Viagra is used to treat erectile dysfunction (impotence) in men. Another brand of sildenafil is Revatio, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women.

Sildenafil may also be used for other purposes not listed in this medication guide.

Precautions

Do not take sildenafil if you are also using a nitrate drug for chest pain or heart problems. This includes nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur, Nitro-Bid, and others), isosorbide dinitrate (Dilatrate-SR, Isordil, Sorbitrate), and isosorbide mononitrate (Imdur, ISMO, Monoket). Nitrates are also found in some recreational drugs such as amyl nitrate or nitrite ("poppers”). Taking sildenafil with a nitrate medicine can cause a serious decrease in blood pressure, leading to fainting, stroke, or heart attack.

Before taking sildenafil, 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 sildenafil.

Sildenafil 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 sildenafil, 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 sildenafil is the actual cause of vision loss. Stop using sildenafil 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 sildenafil without telling your doctor if you are pregnant or plan to become pregnant during treatment.

It is not known if sildenafil passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Avoid drinking alcohol, which can increase some of the side effects of sildenafil.

Avoid using other medicines to treat impotence, such as alprostadil (Caverject, Muse, Edex) or yohimbine (Yocon, Yodoxin, others), without first talking to your doctor.

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Instructions

Seek emergency medical attention if you think you have used too much of this medicine. Overdose symptoms may include chest pain, nausea, irregular heartbeat, and feeling light-headed or fainting.

Viagra is used as needed, so you are not likely to be on a dosing schedule.

If you miss a dose of Revatio, take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

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Side Effects

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

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 sildenafil.

Stop using sildenafil and call your doctor at once if you have any of these serious side effects:

  • 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;
  • vision changes;
  • feeling light-headed, fainting; or
  • penis erection that is painful or lasts 4 hours or longer.

Less serious side effects may include:

  • warmth or redness in your face, neck, or chest;
  • stuffy nose;
  • headache;
  • memory problems;
  • upset stomach; or
  • back pain.

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.

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Interactions

Do not take sildenafil if you are also using a nitrate drug for chest pain or heart problems, including nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur, Nitro-Bid, Minitran, Deponit, Transderm-Nitro), isosorbide dinitrate (Dilatrate-SR, Isordil, Sorbitrate), and isosorbide mononitrate (Imdur, ISMO, Monoket), or recreational drugs such as amyl nitrate or nitrite ("poppers”).

Before taking sildenafil, tell your doctor about all other medications you use for erectile dysfunction, or if you are using any of the following medications:

  • bosentan (Tracleer);
  • cimetidine (Tagamet, Tagamet HB);
  • conivaptan (Vaprisol);
  • diclofenac (Arthrotec, Cataflam, Voltaren, Flector Patch, Solareze);
  • enoxacin (Penetrex);
  • imatinib (Gleevec);
  • isoniazid (for treating tuberculosis);
  • rifampin (Rifadin, Rimactane);
  • an antidepressant such as nefazodone;
  • an antibiotic such as clarithromycin (Biaxin), dalfopristin/quinupristin (Synercid), erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin), or telithromycin (Ketek);
  • an antifungal medication such as clotrimazole (Mycelex Troche), itraconazole (Sporanox), ketoconazole (Nizoral), or voriconazole (Vfend);
  • heart or blood pressure medication such as diltiazem (Cardizem, Dilacor, Tiazac), doxazosin (Cardura), nicardipine (Cardene), quinidine (Quinaglute, Quinidex, Quin-Release), or verapamil (Calan, Covera, Isoptin, Verelan); or
  • HIV/AIDS medicine such as amprenavir (Agenerase), atazanavir (Reyataz), delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), saquinavir (Invirase), or ritonavir (Norvir).

This list is not complete and there may be other drugs that can interact with sildenafil. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Other Names

Revatio, Viagra, and sildenafil

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Disclaimer

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04

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