Viagra

Viagra is a member of the group of drugs known as phosphodiesterase type 5 inhibitors. It works by promoting dilation of the blood vessels in the penis during sexual arousal. As a result, blood flows more easily into the penis, making it possible to achieve an erection naturally.

If you do not suffer from erectile dysfunction, you should not take Viagra. This medicine is not suitable for women.

Drug is indicated, on medical prescription, for the treatment of erectile dysfunction, sometimes referred to as impotence. This occurs when a man cannot obtain or maintain a rigid erection of the penis sufficient for sexual intercourse.

Viagra does not increase libido or affect fertility.

What does Viagra contain?

Active substance

The active ingredient in this medicine is sildenafil. Each film-coated tablet is available in dosages of 25 mg, 50 mg, and 100 mg of sildenafil (in the form of sildenafil citrate) respectively.

Excipients

Microcrystalline cellulose, calcium hydrogen phosphate anhydrous, croscarmellose sodium, magnesium stearate, hydroxypropyl methylcellulose, lactose, triacetin, colourings: titanium dioxide (E171), indigotine (E132).

Blue, diamond-shaped tablets with rounded corners marked "VGR 25", "VGR 50" or "VGR 100" on one side and "Pfizer" on the other.

How do I use Viagra?

Your doctor will decide what dose is best for you. For most men, this is 50 mg. But for some men, your doctor may prescribe a higher or lower dose. Never take a higher dose than that prescribed.

Viagra is taken when needed, about one hour before sexual intercourse. Do not use this drug more than once a day.

The film-coated tablet should be swallowed whole with a little water.

Viagra will only promote an erection if you are sexually stimulated. If you are not sexually aroused, it will not produce an erection. The time it takes for Viagra to work varies from man to man; it usually takes between half an hour and an hour. You may find that it takes a little longer if you take it with a heavy meal.

Drinking alcohol may temporarily prevent you from having an erection. To get the best possible effect from your medicine, you should take care not to drink large quantities of alcohol before taking Viagra.

If Viagra does not make your erection easier, or if your erection does not last long enough for you to have full sexual intercourse, tell your doctor.

Do not change the prescribed dosage on your own initiative. Talk to your doctor or pharmacist if you think the drug is too weak or too strong.

A dose of more than 100 mg does not increase the efficacy of the medicine; it only increases the frequency and severity of undesirable effects.

Please inform your doctor if you have taken more tablets than prescribed.

Elderly patients

If you are over 65, your initial dose of Viagra should not, as a general rule, exceed 25 mg.

Patients with liver or kidney disease

Tell your doctor if you have liver or kidney disease. Your doctor will decide whether you should take a lower dose of Viagra.

What side effects can Viagra have?

Very common (may affect more than 1 in 10 people): headache.

Common (may affect 1 to 10 in 100 people): sensation of heat associated with redness of the face, digestive disorders, nasal congestion, dizziness, nausea, hot flushes and visual disturbances (e.g. blurred vision, altered colour perception, sensation of being dazzled, vision of light rings).

Occasional (may affect 1 to 10 people in 1000): colds, hypersensitivity reactions (with symptoms such as skin rashes, itching, facial swelling, shortness of breath, asthma attack or fall in blood pressure [from dizziness to syncope]), drowsiness, reduced sensitivity to touch, pressure and pain (in rare cases, also in the mouth), various eye disorders (e.g. eye pain, conjunctival disorders). Tinnitus, increased pulse, palpitations, nosebleeds, vomiting, dry mouth, abdominal pain, heartburn, muscle pain, pain in the arms, legs or chest, fatigue.

Rare (may affect 1 to 10 people in 10,000): fainting, stroke (with symptoms such as sudden disturbances of vision, double images, dizziness, nausea, vomiting, disturbances of balance and coordination, sensation of deafness, paralysis phenomena, severe headache), convulsions, eye irritations, swelling of the eyes/eyelids, poor eyesight, dry eyes, disturbances of the heart rhythm, heart attack (with symptoms such as a sudden feeling of tightness in the chest or shooting pains in the chest, possibly also radiating to the arms, abdomen or back, respiratory distress, nausea, anxiety, feeling faint), increased blood pressure, stronger/strongly prolonged erection (see below), irritability.

In a few cases, an erection has been prolonged excessively and/or strengthened and sometimes painful after taking Viagra. If you have an erection of this type for more than 4 hours, contact a doctor immediately as this is a urological emergency and may result in irreversible damage to the penis and permanent loss of sexual potency.

In rare cases, men who have taken PDE5 inhibitors, i.e. an active ingredient in the class of substances to which Viagra also belongs, have reported a sudden reduction or even loss of vision in one or both eyes. Please stop taking all PDE5 inhibitors, including Viagra, immediately and consult your doctor if you experience a sudden decrease or loss of visual acuity.

Rare cases of acute myocardial infarction have been reported with Viagra. Most, but not all, of the men concerned already had heart problems before taking the drug.

Rare cases of stroke have been reported. There is no evidence that these events were directly related to Viagra.

Isolated cases of deterioration of the field of vision, protrusion of the eyeball, dilation of the pupils, discolouration of the white of the eye, convulsions, sudden cardiac death, hearing loss or deafness have been reported.

Tell your doctor if you experience any of these side effects (particularly chest pain), if they are very severe, if they last a long time, if they are bothersome or if they worsen with continued treatment.

If you notice any other side effects, please tell your doctor or pharmacist.

When should Viagra not be used?

If you have a heart condition (e.g. angina pectoris, "chest pain") and are being treated with medicines containing nitrate derivatives or substances that release nitric oxide (e.g. molsidomine, nitroglycerine or similar substances), you must never take sildenafil (Viagra). Taking Viagra at the same time as these medicines may dangerously reinforce their effect and cause a drop in blood pressure or circulatory collapse. The same applies to the use of 'poppers' (whose active substance is amyl nitrite) sold illegally.

Do not take Viagra if you are being treated with medicines containing guanylate cyclase stimulators such as riociguat (for dilation of the pulmonary arteries in specific forms of pulmonary hypertension).

If you are taking medication of this type, talk to your doctor. If you are not sure, ask your doctor or pharmacist for advice.

Do not take this medicine if you have ever experienced vision loss in one eye due to insufficient blood supply to your eye (non-arteritic anterior ischaemic optic neuropathy [NAION]), or if there are cases of certain rare eye diseases (such as retinitis pigmentosa) in your family.

Do not take this drug if you have ever had a hypersensitive (allergic) reaction to sildenafil or any of the other ingredients of Viagra. An allergic reaction may take the form of a skin rash, itching, facial congestion, swelling of the lips or shortness of breath. If you have already had one or more of these reactions, you should tell your doctor.

Medication must not be administered to children or young people under the age of 18.

What precautions should I take when taking Viagra?

In the case of acute cardiovascular disorders or conditions, you should not be treated with nitrate-containing medicines if you have previously taken a medicine containing the active substance sildenafil. Concomitant administration of such medicines may cause a fall in blood pressure of a potentially fatal magnitude. You should also avoid using amyl nitrite, a substance sold illegally and contained in so-called "poppers".

Sexual activity can overload the heart and therefore carries a certain risk for patients with serious heart disease. Before prescribing Viagra, tell your doctor if you have suffered a stroke or myocardial infarction, have heart disease, chest pain (angina pectoris), other heart problems or low blood pressure.

Sudden onset of heart pain is an emergency situation requiring immediate medical treatment. All those treating you must be informed that you have taken Viagra. This information is important for the continuation of your treatment!

Also inform your doctor if you are taking guanylate cyclase stimulators such as riociguat, as these can lower your blood pressure even further.

Tell your doctor if you are taking blood pressure medication. Some patients taking an alpha-blocker to treat high blood pressure or prostate problems may experience dizziness or lightheadedness when standing. These phenomena are symptoms of orthostatic hypotension triggered when blood pressure is too low during the rapid transition to a sitting or standing position. Some patients have experienced these symptoms when taking Viagra at the same time as alpha-blockers. These phenomena usually occur within 4 hours of taking Viagra. In order to reduce the likelihood of these symptoms occurring, you should be stabilised on your alpha-blocker treatment before taking Viagra. In this case, your doctor will probably prescribe an initial dose of Viagra of 25 mg.

In a large-scale study, an increased risk of retinal detachment was reported with the regular use of PDE5 inhibitors such as sildenafil. If you notice any symptoms of retinal detachment (flashes of light, black spots, a dark haze or a reduced field of vision), consult an ophthalmologist immediately.

Contact a doctor immediately in the event of sudden disturbances of vision or loss of vision in one or both eyes. Such an event may result in permanent loss of vision. In such a case, Viagra should no longer be used.

In the presence of the following diseases, you should also discuss the use of phosphodiesterase type 5 inhibitor with your doctor:

• Sickle cell anaemia (red blood cell abnormality), leukaemia (blood cancer), multiple myeloma (bone marrow cancer), liver disease, penile disease or deformity of any kind. In these cases, it may be necessary to take special precautions during treatment.
• Gastric ulcer or blood clotting disorder (e.g. haemophilia). Viagra may have adverse effects on these diseases.
• Intolerance to certain sugars (congenital galactose intolerance, lactase deficiency or glucose-galactose malabsorption) as Viagra film-coated tablets contain lactose.

Interactions with other medicines

Sildenafil may interfere adversely with other medicines. Do not take Viagra with other medicines unless your doctor has agreed.

This drug may seriously enhance the effects of medicines containing nitrate derivatives or substances that release nitric oxide (e.g. molsidomine, nitroglycerine or similar substances). The concomitant administration of these medicines with Viagra is strictly prohibited.

Under no circumstances should you use Viagra at the same time as other medicines for the treatment of erectile dysfunction.

There is a whole range of medicines that slow down or prevent the breakdown of Viagra's active substance in the liver. This may enhance the effect of sildenafil, but also its undesirable effects (side-effects). These include certain antibiotics ("macrolides" such as clarithromycin), medicines to treat fungal infections (e.g. itraconazole), certain medicines used in the treatment of HIV (protease inhibitors) or medicines to treat excess gastric secretion or gastric ulcers, the active substance of which is cimetidine.

If you are taking protease inhibitors for the treatment of HIV infection, your doctor may prescribe Viagra starting with the lowest dose (25 mg).

Please inform your doctor or pharmacist if:

• you suffer from any other illness,
• you have allergies,
• you are already taking other medicines internally or externally (even if you are self-medicating!).

Effect on ability to drive and use machines

This medicine may affect reactions and the ability to drive and use tools or machines.

Taking Viagra may cause dizziness and visual disturbances, such as blurred vision or abnormal colour perception. You should therefore know how you react to sildenafil before driving a vehicle or operating machinery. It should also be taken into account for activities where accurate colour discrimination is essential.

Where do you get Viagra? What packaging is available on the market?

Viagra is sold in pharmacies only on presentation of a doctor's prescription.

• 25 mg film-coated tablets: 4 and 12
• 50 mg film-coated tablets: 4, 12 and 24
• 100 mg film-coated tablets: 4, 12 and 24.