This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
12.3 Pharmacokinetics
Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or sildenafil film tablet keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the lungs, causing shortness of breath, dizziness, and tiredness). 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.
What should I know about sildenafil before taking it?
Sildenafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow easily. If you are taking sildenafil to treat erectile dysfunction, you should know 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 human immunodeficiency virus (HIV). Sildenafil comes as a tablet and suspension (liquid) to take by mouth. If you are taking sildenafil to treat erectile dysfunction, follow your doctor's directions and the guidelines in this paragraph. tell your doctor and pharmacist if you are allergic to sildenafil, any other medications, or any of the ingredients in sildenafil tablet or suspension.
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Kamagra Polo | 100mg | 272 + 12 Pills | 622.94€ 593.28€ | |
| Kamagra | 100mg | 360 + 6 Pills | 839.95€ 799.95€ | |
| Viagra Generic | 100mg | 120 + 6 Pills | 149.50€ 142.38€ | |
| Viagra Generic | 100mg | 180 + 8 Pills | 199.37€ 189.88€ | |
| Kamagra Polo | 100mg | 32 Pills | 125.88€ 119.89€ | |
| Viagra Generic | 150mg | 60 + 4 Pills | 111.25€ 105.95€ | |
| Viagra Generic | 50mg | 10 Pills | 26.87€ 25.59€ | |
| Viagra Generic | 150mg | 30 + 2 Pills | 72.32€ 68.88€ | |
| Viagra Generic | 25mg | 120 + 6 Pills | 125.56€ 119.58€ | |
| Viagra Generic | 100mg | 10 Pills | 28.91€ 27.53€ |
Ask your pharmacist for a list of the ingredients.
Mechanism of action
Shake the liquid well for 10 seconds before each use to mix the medication evenly. Use the oral syringe provided with your medication to measure and take your dose. Follow the manufacturer's directions to use and clean 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 probably start you on an average dose of sildenafil and increase or decrease your dose depending on your response to the medication.
Organic Nitrates, Nitrites, and Nitric Oxide Donors
Tell your doctor sildenafil generic if sildenafil is not working well or if you are experiencing side effects. If you are taking sildenafil for PAH, you should know that sildenafil controls PAH but does not cure it. Continue to take sildenafil even if you feel well. Do not stop taking sildenafil without talking to your doctor. Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient. Some medications should not be taken with sildenafil.
| Property | Description | Value | Notes |
|---|---|---|---|
| Molecular Formula | C22H30N6O4S | ||
| Molecular Weight | 474.58 g/mol | ||
| Melting Point | 189-192°C | ||
| Solubility in Water | Slightly soluble | at 25°C | |
| pH Range | 3.8 - 4.0 | in aqueous solution |
Make sure you have discussed any other medications you are currently taking or plan to take before starting sildenafil with your doctor and pharmacist.
2.4 Dosage Adjustments Due to Drug Interactions
You’ll need to have sexual stimulation or feel sexually aroused to get an erection. If nothing happens, or if not enough happens, you should inform your doctor. You may experience side effects, and some are more common than others You may experience side effects, and some are more common than others Sildenafil may cause side effects which include dizziness and altered vision. You should be aware of your personal reaction to sildenafil before you drive or operate heavy machinery whilst taking it. Sildenafil may cause side effects which include dizziness and altered vision.
Drugs you should not use with sildenafil
you experience any sudden decrease or loss of vision; you experience any sudden decrease or loss of vision; you experience any allergic reaction, such as wheeze, breathing difficulties, or swelling around the eyes or airways; you experience any allergic reaction, such as wheeze, breathing difficulties, or swelling around the eyes or airways; (If you are on nitrate medications for chest pain, do not take them.) (If you are on nitrate medications for chest pain, do not take them.) Severe side effects are rare, but they do happen. If you do experience any of the above severe side effects, you should seek urgent medical attention. Handled correctly, sildenafil citrate is a generally safe and effective way to treat erectile dysfunction. But you should always read the Patient Information Leaflet before taking it. To find out more, book a consultation with one of our clinicians. Before starting, stopping, or changing any medications while taking sildenafil, please get the advice of your doctor or pharmacist. tell your doctor if you are taking street drugs containing nitrates ('poppers') such as amyl nitrate, amyl nitrite, or butyl nitrate while taking sildenafil. Your doctor will tell you not to take sildenafil if you are taking street drugs containing nitrates.
Other Comments
You should not take sildenafil film-coated tablets in combination with sildenafil oro-dispersible tablets. Take your sildenafil about an hour before you plan to have sex. Swallow the tablet whole with a glass of water. You can take it with or without food, but you might find that the effect takes longer to start if you’ve eaten heavily. Alcohol can interfere with your ability to get an erection (we’ve written about it in detail here), so to maximise the benefit of sildenafil, it’s best to give the beer a miss.
Can you take Viagra if you have high blood pressure?
Grapefruit juice may increase the incidence of unwanted side effects of sildenafil. The effects of sildenafil last approximately four hours, which means your erectile function is improved for four hours. The effects of sildenafil become evident when you are sexually stimulated or aroused. You should not have an erection for four hours - a prolonged and painful erection (priapism) is a surgical emergency, and you should seek urgent medical attention should this happen. Most people feel the effect of sildenafil in 45 minutes or so. tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
4.3 Concomitant Guanylate Cyclase (GC) Stimulators
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 from 4 hours to 30 minutes before sexual activity. Sildenafil usually should not be taken more than once every 24 hours. If you have certain health conditions or are taking certain medications, your doctor may tell you to take sildenafil less often. You can take sildenafil with or without food.
What to do if you think you’ve taken too much Viagra
However, if you take sildenafil with a high-fat meal, it will take longer for the medication to start to work. If you are taking sildenafil to treat PAH, you will probably take sildenafil three times a day with or without food. Take sildenafil at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Do not take more or less of it or take it more often than prescribed by your doctor. you should know that sildenafil is available under the brand names Liqrev, Revatio, and Viagra.
2.1 Dosage Information
Increasing blood flow through the arteries in the penis means improved erectile function. Cells in your arteries normally release nitric oxide, which, via molecular messengers including cGMP, sends instructions to muscle proteins to relax. This causes increased blood flow into your penis, which causes an erection. An enzyme called PDE-5 normally breaks down that cGMP, which reverses that relaxation, allowing your erection to subside. Sildenafil, a PDE-5 inhibitor, helps maintain that erection instead.
Erectile dysfunction
There are some situations where you should not take sildenafil. You’re taking medications known as nitrates You’re taking medications known as nitrates You’re taking amyl nitrites (also known as “poppers”) You’re taking amyl nitrites (also known as “poppers”) You’re taking medications known as protease inhibitors You’re taking medications known as protease inhibitors You’re taking medications known as alpha-blockers You’re taking medications known as alpha-blockers You’re already taking sildenafil or any other PDE5 inhibitor in another form You’re already taking sildenafil or any other PDE5 inhibitor in another form You have any heart, liver or kidney problems You have any heart, liver or kidney problems You are taking medications for pulmonary arterial hypertension You are taking medications for pulmonary arterial hypertension You’re under the age of 18 You’re under the age of 18 The recommended starting dose is 50 mg. You shouldn’t take this more than once within a 24 hour period. Taking it more than once a day will increase the chance of side effects. If, after taking sildenafil, you feel the effect is too strong or too weak, you should talk to your doctor or pharmacist who may suggest an adjusted dosage for you or an alternative treatment. You should only be treated with one of these products at a time.
- Sildenafil citrate is used to treat erectile dysfunction.
- It enhances blood flow to the penis for a stronger erection.
- Commonly available in tablet form for oral use.
The following nonprescription or herbal products may interact with sildenafil: cimetidine (Tagamet HB), St. John's wort. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking sildenafil.
| Medication Class | Interaction Type | Effect | Clinical Significance |
|---|---|---|---|
| Nitrates | Additive hypotensive effect | Severe hypotension | Contraindicated |
| Alpha-blockers | Enhanced hypotension | Blood pressure drop | Use with caution |
| CYP3A4 inhibitors | Increased sildenafil levels | Prolonged or intensified side effects | Dose adjustment may be needed |
| Protease inhibitors | Elevated sildenafil levels | Increased adverse effects | Monitoring required |
Do not start these medications while taking sildenafil without discussing it with your healthcare provider. tell your doctor if you smoke, if you have had heart surgery within the last 6 months, if you have ever had an erection that lasted for more than 4 hours, and if you have recently lost a large amount of body fluids (dehydration).
- Overdose symptoms may include dizziness, nausea, or prolonged erections.
- Seek emergency help if an erection lasts over 4 hours.
- Avoid excessive dosing to prevent adverse events.
This can happen if you are sick with fever, diarrhea, or vomiting; sweat a lot; or do not drink enough liquids.
| Condition | Risk | Recommendations |
|---|---|---|
| Concomitant Nitrate Use | Severe hypotension | Avoid combination |
| Cardiac Conditions | Risk of myocardial infarction or arrhythmia | Consult cardiologist |
| Severe Liver Impairment | Altered drug metabolism | Dose adjustment needed |
| Hypotension (low BP) | Further blood pressure reduction | Use with caution |
Also tell your doctor if you have or have ever had pulmonary veno-occlusive disease (PVOD; blockage of veins in the lungs); a stomach ulcer; heart, kidney, or liver disease; a heart attack; heart failure; angina (chest pain); an irregular heartbeat; a stroke; chest pain; high or low blood pressure; high cholesterol; a bleeding disorder; blood circulation problems; blood cell problems such as sickle cell anemia (a disease of the red blood cells), multiple myeloma (cancer of the plasma cells), or leukemia (cancer of the white blood cells); conditions affecting the shape of the penis (e.g., angulation, cavernosal fibrosis, or Peyronie's disease); or diabetes.