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US Brand Names

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Description

Sildenafil belongs to a group of medicines that delay the enzymes called phosphodiesterases from working too quickly. The penis is one of the areas where these enzymes work. Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence).

By controlling the enzyme phosphodiesterase, sildenafil helps to maintain an erection that is produced when the penis is stroked. Without physical action to the penis, such as that occurring during sexual intercourse, sildenafil will not work to cause an erection.

Sildenafil is also used in both men and women to treat the symptoms of pulmonary arterial hypertension. This is the high blood pressure that occurs in the main artery that carries blood from the right side of the heart (the ventricle) to the lungs. When the smaller blood vessels in the lungs become more resistant to blood flow, the right ventricle must work harder to pump enough blood through the lungs. Sildenafil helps by increasing the supply of blood to the lungs and reducing the workload of the heart .

This medicine is available only with your doctor's prescription.

This product is available in the following dosage forms:

• Tablet

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Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Geriatric

Elderly people are especially sensitive to the effects of sildenafil, which may increase their chance of having side effects. Patients 65 years of age and older who are taking this medicine for erectile dysfunction are started on a low dose, 25 mg, of sildenafil. Patients who are taking this medicine for pulmonary arterial hypertension may also need to be started at a lower dose. The dose may be increased by a doctor as needed and tolerated .

Pregnancy

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Amyl Nitrite
• Erythrityl Tetranitrate
• Isosorbide Dinitrate
• Isosorbide Mononitrate
• Molsidomine
• Nitroglycerin
• Nitroprusside
• Pentaerythritol Tetranitrate

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Age greater than 50 years or
• Coronary artery disease or
• Diabetes or
• Hyperlipidemia (excess of lipids in the blood) or
• Hypertension (high blood pressure) or
• Low cup to disc ratio ("crowded disc") or
• Smoking—These conditions may increase risk for a serious eye problem called NAION .

• Arrhythmias (irregular heartbeat) or
• Coronary artery disease or
• Heart attack, history of (within the last 6 months) or
• High blood pressure or
• Low blood pressure or
• Stroke, history of (within the last 6 months)—Chance of problems occurring may be increased.

• Abnormal penis, including curved penis and birth defects of the penis—Chance of problems occurring may be increased.

• Bleeding problems or
• Retinitis pigmentosa—Chance of problems occurring may be increased. It is not known if the medicine is safe for use in these patients.

• Conditions causing thickened blood or slower blood flow, including leukemia; multiple myeloma (tumors of the bone marrow); or polycythemia, sickle cell disease, and thrombocythemia (blood problems) or
• Priapism (history of)—Although sildenafil does not cause priapism (erection lasting longer than 6 hours), patients with these conditions have an increased risk of priapism and it could occur while using sildenafil.

• Heart or blood disease—Sexual activity increases the heart rate and blood flow and can increase the chance of problems occurring for some patients who use any type of medicine, including sildenafil, that increases sexual ability.

• Kidney problems (severe) or
• Liver problems (severe)—Chance of problems occurring may be increased. Lower starting doses may be used and doses increased as needed and as tolerated.

• NAION (serious eye condition) in one or both eyes, previously—May increase your chance of getting NAION again .

• Pulmonary veno-occlusive disease (high blood pressure in the blood vessels of the lungs)—May make heart problems worse in patients with this serious condition .

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Proper Use

Special patient directions come with sildenafil. Read the directions carefully before using the medicine.

This medicine usually begins to work within 30 minutes after taking it for erectile dysfunction. It continues to work for up to 4 hours, although its action is usually less after 2 hours .

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For oral dosage form (tablets):
  • For treatment of erectile dysfunction:
    • Adults up to 65 years of age—50 mg as a single dose no more than once a day, 1 hour before sexual intercourse. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. If needed, your doctor may increase your daily dose to 100 mg or decrease your daily dose to 25 mg.
    • Adults 65 years of age and older—25 mg as a single dose no more than once a day, 1 hour before sexual intercourse. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. If needed, your doctor may increase your daily dose.
    • If you are taking protease inhibitors, such as for the treatment of HIV, your doctor may recommend a 25 mg dose and may limit you to a maximum single dose of 25 mg of Viagra in a 48 hour period.
  • For treatment of pulmonary arterial hypertension:
    • Adults—20 mg three times per day. Each dose should be taken about 4 to 6 hours apart and can be taken with or without food .
    • Children—Use and dose must be determined by your doctor .

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

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Precautions

Sildenafil has not been studied with other medicines used for treatment of erectile dysfunction. Presently, using them together is not recommended.

It is important that you tell all of your healthcare providers that you take sildenafil. If you need emergency medical care for a heart problem, it is important that your healthcare provider knows when you last took sildenafil .

Use sildenafil exactly as directed by your doctor. Do not use more of it and do not use it more often than your doctor ordered. If too much is used, the chance of side effects is increased.

If you experience a prolonged or painful erection for 4 hours or more, contact your doctor immediately. This condition may require prompt medical treatment to prevent tissue damage of the penis and possible permanent impotence.

This medicine does not protect you against sexually transmitted diseases. Use protective measures and ask your doctor if you have any questions about this .

It is important to tell your doctor about any heart problems you may have now or may have had in the past. This medicine can cause serious side effects in patients with heart problems .

If you experience sudden loss of vision in one or both eyes, stop using sildenafil and contact your doctor immediately .

Also stop using this medicine and check with your doctor right away if you have sudden decrease in hearing or loss of hearing, which may be accompanied by dizziness and ringing in the ears.

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Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

• Abnormal vision, including blurred vision, seeing shades of colors differently than before, or sensitivity to light
• Bladder pain
• Burning feeling in chest or stomach
• Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• Cloudy or bloody urine
• Dizziness
• Increased frequency of urination
• Indigestion
• Pain on urination
• Stomach upset
• Tenderness in stomach area

• Bleeding of the eye
• Convulsions (seizures)
• Decreased vision or other changes in vision
• Double vision
• Prolonged, painful, or inappropriate erection of penis
• Redness, burning, or swelling of the eye
• Vision loss, temporary

• Blood sugar problems (more likely with patients with diabetes mellitus), such as anxiety, behavior change similar to drunkenness, blurred vision, cold sweats, confusion, cool and pale skin, difficulty in concentrating, drowsiness, excessive hunger, fast heartbeat, headache, nausea, nervousness, nightmares, restless sleep, shakiness, slurred speech, and unusual tiredness or weakness
• Bone pain
• Breast enlargement
• Chest pain
• Chills
• Confusion
• Convulsions (seizures)
• Deafness or hearing loss
• Decrease in amount of urine or in frequency of urination
• Dizziness or lightheadedness, especially when getting up from a lying or sitting position
• Dry eyes
• Dry mouth
• Dryness, redness, scaling, or peeling of the skin
• Eye pain
• Fainting or faintness
• Fast, irregular, or pounding heartbeat
• Feeling of something in the eye
• Groups of skin lesions with swelling
• Headache (severe or continuing)
• Heart failure
• Hives
• Increase in size of pupil
• Increased sweating
• Increased thirst
• Itching of skin
• Low blood pressure
• Lower back or side pain
• Migraine headache
• Nausea (severe or continuing)
• Nervousness
• Numbness of hands
• Painful, swollen joints
• Redness, itching, or tearing of eyes
• Shortness of breath or troubled breathing
• Skin paleness
• Skin rash
• Skin ulcers
• Sore throat and fever or chills
• Sudden weakness
• Swelling of face, hands, feet, or lower legs
• Twitching of muscles
• Unusual tiredness or weakness
• Unusual feeling of burning or stinging of skin

• Blindness

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Aches or pains in muscles
• Bloody nose
• Diarrhea
• Difficult or labored breathing
• Flushing
• Headache
• Nasal congestion
• Pain or tenderness around eyes and cheekbones
• Redness of skin
• Sneezing
• Stomach discomfort following meals
• Stuffy or runny nose
• Trouble in sleeping
• Unusually warm skin

• Anxiety

• Abdominal pain
• Abnormal dreams
• Clumsiness or unsteadiness
• Cough
• Diarrhea or stomach cramps (severe or continuing)
• Difficulty in swallowing
• Ear pain
• Increased amount of saliva
• Increased skin sensitivity
• Lack of coordination
• Loss of bladder control
• Mental depression
• Nausea
• Numbness or tingling of hands, legs, or feet
• Rectal bleeding
• Redness or irritation of the tongue
• Redness, soreness, swelling, or bleeding of gums
• Ringing or buzzing in ears
• Sensation of motion, usually whirling, either of one's self or of one's surroundings
• Sexual problems in men (continuing), including failure to experience a sexual orgasm
• Sleepiness
• Sores in mouth and on lips
• Tense muscles
• Tightness of chest or wheezing
• Trembling and shaking
• Vomiting
• Waking to urinate at night
• Worsening of asthma

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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