Why is this medication prescribed?
Sildenafil (Viagra) is used to treat erectile dysfunction (impotence, inability to achieve or maintain an erection) in men. Le sildenafil (Revatio) is used to improve the capacity to exercise chez les adultes souffrant d’hypertension arterielle pulmonaire (HTAP ; hypertension arterielle dans les vaisseaux qui transportent le sang vers les poumons, causing an essoufflement, des étourdissements et de the fatigue). Sildenafil should not usually be taken by children, but in some cases a doctor may decide that sildenafil (Revatio) is the best medication to treat a child’s condition. Sildenafil is in a class of medications called phosphodiesterase (PDE) inhibitors. Sildenafil treats erectile dysfunction by increasing blood flow to the penis during sexual stimulation. This increased blood flow can cause an erection. Sildenafil treats PAH by relaxing the blood vessels in the lungs so blood can flow more easily.
If you are taking sildenafil to treat erectile dysfunction, be aware that it does not cure erectile dysfunction or increase sexual desire. Sildenafil does not prevent pregnancy or the spread of sexually transmitted diseases such as the human immunodeficiency virus (HIV).
How should this medicine be used?
Sildenafil comes as a tablet and a suspension (liquid; Revatio only) to take by mouth.
If you are taking sildenafil to treat erectile dysfunction, follow your doctor’s instructions and guidelines in this paragraph. Take sildenafil as needed before sexual activity. The best time to take sildenafil is about 1 hour before sexual activity, but you can take the medication any time between 4 hours and 30 minutes before sexual activity. Sildenafil should not usually be taken more than once every 24 hours. If you have certain health conditions or take certain medications, your doctor may direct you to take sildenafil less often. You can take sildenafil with or without food. However, if you take sildenafil with a high-fat meal, it will take longer for the medicine to start working.
If you are taking sildenafil to treat PAH, follow your doctor’s instructions and guidelines in this paragraph. You will probably take sildenafil three times a day with or without food. Take sildenafil at around the same time each day, and space your doses 4 to 6 hours apart.
Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take sildenafil exactly as directed. Do not take more, less, or more often than prescribed by your doctor.
Shake the liquid well for 10 seconds before each use to mix the medication evenly. Use the oral syringe provided with your medicine to measure and take your dose. Follow the manufacturer’s instructions for using and cleaning the oral syringe. Do not mix the liquid with other medications or add anything to flavor the medication.
If you are taking sildenafil for erectile dysfunction, your doctor will likely prescribe a medium dose of sildenafil and increase or decrease your dose based on your response to the medication. Tell your doctor if sildenafil does not work well or if you experience side effects.
If you are taking sildenafil for PAH, keep in mind that sildenafil controls PAH but does not cure it. Keep taking sildenafil even if you feel fine. Do not stop taking sildenafil without talking to your doctor.
Ask your pharmacist or doctor for a copy of the manufacturer’s patient information.
Other uses of this medicine
This drug is sometimes prescribed for other uses. Consult your doctor or pharmacist for more information.
What special dietary instructions must I follow?
Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medicine.
What should I do if I miss a dose?
If you are taking sildenafil for erectile dysfunction, it is unlikely that you will miss a dose because this medication is taken as needed and not on a regular dosing schedule.
If you are taking sildenafil for PAH, take the missed dose as soon as you remember. However, if it is time for the next dose, skip the missed dose and go back to your regular dosing schedule. Do not take a double dose to make up.
What secondary effects can this medication cause?
Sildenafil can cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- stomach irritation
- redness (feeling hot)
- difficulty falling asleep or staying asleep
- numbness, burning, or tingling in the hands, arms, legs, or feet
- muscle pains
- Changes in color vision (seeing a bluish tint to objects or having trouble telling the difference between blue and green)
- light sensitivity
- Some side effects can be serious. If you experience any of the following symptoms, call your doctor right away:
- Severe and sudden vision loss (see below for more information)
- Blurry vision
- sudden decrease or loss of hearing
- Ringing in the ears
- dizziness or lightheadedness
- Chest pain
- increased shortness of breath
- an erection that is painful or lasts more than 4 hours
- itching or burning when urinating
Some patients have experienced a sudden loss of all or part of their vision after taking sildenafil or other medicines similar to sildenafil. In some cases, the vision loss was permanent. It is not known if the drug caused the vision loss. If you experience sudden vision loss while taking sildenafil, call your doctor immediately. Do not take more doses of sildenafil or similar medications such as tadalafil (Cialis) or vardenafil (Levitra) until you have talked with your doctor.
Heart attacks, strokes, irregular heartbeats, bleeding in the brain or lungs, high blood pressure, and sudden death have been reported in men taking sildenafil for erectile dysfunction. Most of these people had heart problems before taking sildenafil, but not all. It is not known whether these events were caused by sildenafil, sexual activity, heart disease, or a combination of these and other reasons. talk to your doctor about the risks of taking sildenafil.
Some patients have experienced a sudden decrease or loss of hearing after taking sildenafil or other medicines similar to sildenafil. Hearing loss usually affects only one ear and does not always improve when the medication is stopped. It is not known if the hearing loss was caused by the drug. Call your doctor right away if you experience sudden hearing loss, sometimes accompanied by ringing in the ears or dizziness, while taking sildenafil. If you are taking sildenafil (Viagra) for erectile dysfunction, do not take more doses of sildenafil (Viagra) or similar medications such as tadalafil (Cialis) or vardenafil (Levitra) until directed by your doctor. If you are taking sildenafil (Revatio) for PAH, do not stop taking your medication until you have talked with your doctor.
Sildenafil may cause other side effects. Call your doctor if you have any unusual problems while taking this medicine.
What should I know about the storage and disposal of this medicine?
Keep this medication in its original container, tightly closed, and out of the reach of children. Store the tablets at room temperature away from excessive heat and moisture (not in the bathroom). Store the suspension at room temperature or in the refrigerator, but do not freeze it. Discard any unused suspension after 60 days.
It is important to keep all medicines out of the sight and reach of children, as many containers (such as those for weekly pill boxes and eye drops, creams, patches, and inhalers) are not leak-proof. children and young children can easily open them. To protect young children from poisoning, always close safety caps and immediately store medications in a safe place, a place that is out of the way and out of sight and reach.
Unnecessary medicines must be disposed of in a special way to ensure that pets, children and others cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to get rid