The Chemical Structure of Sildenafil Citrate
Sildenafil usually should not be taken more than once every 24 hours.
Before taking this medicine
Viagra isn’t approved for use in females. And it hasn’t been studied in pregnant people. It’s unknown whether this drug is safe to take during pregnancy. In animal studies, Viagra didn’t cause fetal harm when given to pregnant animals. But animal studies don’t always predict what will happen in humans.
Natural and over-the-counter alternatives for ED
If you have questions about the safety of Viagra use during pregnancy, talk with your doctor. It’s not known if Viagra is safe to take during pregnancy. (But keep in mind that the drug isn’t approved for use in females.) If you’re sexually active and you or your partner can become pregnant, talk with your doctor about whether you’ll need to use birth control while you’re taking Viagra. And it hasn’t been studied in people who are breastfeeding. Viagra may pass into breast milk, but it’s not known if this could affect a breastfed child.
Prior authorization
If you have questions about the safety of using Viagra while breastfeeding, talk with your doctor. Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. 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.
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Viagra Generic | 200mg | 360 + 10 Pills | 481.98€ 459.03€ | |
| Viagra Generic | 50mg | 20 Pills | 40.52€ 38.59€ | |
| Viagra Generic | 200mg | 60 + 4 Pills | 125.19€ 119.23€ | |
| Kamagra Polo | 100mg | 180 + 8 Pills | 446.52€ 425.26€ | |
| Kamagra Oral Jelly | 100mg | 110 + 9 Sachets | 334.87€ 318.92€ | |
| Viagra Generic | 150mg | 20 Pills | 55.02€ 52.40€ | |
| Viagra Generic | 150mg | 180 + 10 Pills | 236.46€ 225.20€ | |
| Kamagra Soft Tabs | 100mg | 84 + 4 Pills | 233.05€ 221.95€ | |
| Kamagra Polo | 100mg | 84 + 4 Pills | 244.49€ 232.85€ | |
| Kamagra Oral Jelly | 100mg | 220 + 18 Sachets | 662.24€ 630.70€ | |
| Viagra Generic | 50mg | 270 + 8 Pills | 198.48€ 189.03€ | |
| Viagra Generic | 200mg | 20 Pills | 61.69€ 58.75€ | |
| Kamagra Oral Jelly | 100mg | 21 Sachets | 95.92€ 91.35€ | |
| Viagra Generic | 100mg | 270 + 10 Pills | 270.47€ 257.59€ | |
| Viagra Generic | 50mg | 360 + 10 Pills | 225.33€ 214.60€ |
However, if you take sildenafil with a high-fat meal, it will take longer for the medication to start to work.
- Sildenafil shortens the time to achieve an erection.
- It does not cause spontaneous erections without sexual stimulation.
- Overdose signs include vision changes, persistent erections, or hypotension.
- It is linked to priapism, a sustained and painful erection.
- Always consult a healthcare provider before starting sildenafil.
- Store medication in a cool, dry place away from children.
- Combining with recreational drugs can cause dangerous interactions.
If you are taking sildenafil to treat PAH, you will probably take sildenafil three times a day with or without food.
| Parameter | Description | Typical Value |
|---|---|---|
| Absorption Rate | Time to reach peak plasma concentration | 30-120 minutes |
| Bioavailability | Percentage of dose reaching systemic circulation | 40% |
| Half-life | Time to reduce plasma concentration by half | 4 hours |
| Metabolism | Primary site of metabolism | Liver (CYP3A4 enzyme) |
| Excretion | Main routes of elimination | Feces and urine |
Take sildenafil at around the same times every day.
What special precautions should I follow?
Sildenafil tablets should not be used with REVATIO® or with other PAH treatments containing sildenafil or any other PDE5 inhibitors (such as Adcirca® (tadalafil)). Telemedicine does not replace your primary care physician. It is important to keep your primary care physician and pharmacist informed of all medications you are taking, including those in your Keeps treatment plan, as they can interact with other medicines you may be taking. Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or pfizer sildenafil 50 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).
Interactions that increase your risk for side effects
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 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.
Professional resources
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. 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. 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.
- Sildenafil citrate is manufactured by several pharmaceutical companies.
- Its chemical formula is C22H30N6O4S.
- It has a half-life of approximately 4 hours in the body.
- The drug enhances nitric oxide activity in the corpus cavernosum.
- It’s important to follow prescribed dosing to avoid adverse effects.
- It is classified as a phosphodiesterase type 5 inhibitor.
- Sildenafil was initially researched for angina before ED use.
Shake the liquid well for 10 seconds before each use to mix the medication evenly.
Advice To Patients
If you have these symptoms, stop taking sildenafil tablets and contact a doctor right away. The most common side effects of sildenafil tablets are: abnormal vision, such as changes in color vision (such as having a blue color tinge) and blurred vision In addition, heart attack, stroke, irregular heartbeats and death have happened rarely in men taking sildenafil tablets. Most, but not all, of these men had heart problems before taking sildenafil tablets. It is not known if sildenafil 50 mg sildenafil price tablets caused these problems. These are not all the possible side effects of sildenafil tablets.
How it works
Contact your doctor if you have additional questions about side effects. You are encouraged to report negative side effects of prescription drugs to the FDA. Keep out of the reach of children Store at controlled room temperature, between 20°C to 25°C (68°F to 77°F) Throw away any unused medicine after the expiration date As with almost all medicine, the recommended treatments do not work for every single person. There is a risk the medicine will not work and your ED continues. If after more than 4 weeks your symptoms have not improved, you should consider scheduling an in-person visit with a doctor.
Drug form and strengths
Before you take sildenafil tablets, tell your healthcare provider if you: have or have had heart problems such as a heart attack, irregular heartbeat, angina, chest pain, narrowing of the aortic valve or heart failure have had heart surgery within the last 6 months have low blood pressure, or high blood pressure that is not controlled have had an erection that lasted for more than 4 hours have problems with your blood cells such as sickle cell anemia, multiple myeloma, or leukemia have retinitis pigmentosa, a rare genetic (runs in families) eye disease have ever had severe vision loss, including an eye problem called non-arteritic anterior ischemic optic neuropathy (NAION) have kidney problems or are having kidney dialysis Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Especially tell your healthcare provider if you take any of the following: medicines called guanylate cyclase stimulators, such as riociguat (Adempas) medicines called alpha blockers such as Hytrin® (terazosin HCl), Flomax® (tamsulosin HCl), Cardura® (doxazosin mesylate), Minipress® (prazosin HCl), Uroxatral® (alfuzosin HCl), Jalyn® (dutasteride and tamsulosin HCl), or Rapaflo® (silodosin). In some patients, the use of sildenafil tablets with alpha-blockers can lead to a drop in blood pressure or to fainting. medicines called HIV protease inhibitors, such as ritonavir (Norvir®), indinavir sulfate (Crixivan®), saquinavir (Fortovase® or Invirase®) or atazanavir sulfate (Reyataz®) some types of oral antifungal medicines, such as ketoconazole (Nizoral®), and itraconazole (Sporanox®) some types of antibiotics, such as clarithromycin (Biaxin®), telithromycin (Ketek®), or erythromycin other medicines that treat high blood pressure Sildenafil tablets contain sildenafil, which is the same medicine found in another drug called REVATIO®. REVATIO® is used to treat a rare disease called pulmonary arterial hypertension (PAH). Use the oral syringe provided with your medication to measure and take your dose.
- Sildenafil citrate is a medication used primarily for erectile dysfunction.
- It works by relaxing blood vessels to increase blood flow.
- Sildenafil is also prescribed for pulmonary arterial hypertension.
- Common side effects include headache, flushing, and nasal congestion.
- It should be taken 30-60 minutes before sexual activity.
- Alcohol and high-fat meals can reduce its effectiveness.
- Do not take with nitrate medications due to risk of severe hypotension.
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.
| Contraindication | Explanation | Severity Level | Notes |
|---|---|---|---|
| Nitrates use | Can cause severe hypotension | Critical | Avoid concomitant use |
| Heart conditions | Risk of cardiovascular events | Moderate | Consult healthcare provider |
| Hypotension | Low blood pressure | Moderate | Use with caution |
| Retinal Disorders | Potential for vision impairment | Mild | Seek medical advice |
Tell your doctor if sildenafil is not working well or if you are experiencing side effects.
| Patient Group | Starting Dose | Maximum Dose | Frequency | Notes |
|---|---|---|---|---|
| Adult Men with ED | 50 mg | 100 mg | Once per day, 1 hour before sex | Adjust based on efficacy and side effects |
| Patients with Liver Impairment | 25 mg | 50 mg | Once daily | Lower doses recommended |
| Elderly Patients | 25-50 mg | 100 mg | As needed | Monitor for 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.
Drug Interactions
The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses. Please use a modern browser like Chrome, Firefox, or Edge to access this app. Get a recommendation tailored for your needs Sildenafil citrate (sildenafil tablets) is used to treat erectile dysfunction (ED). For full prescribing information, view the drug label information. Viagra® (sildenafil citrate) The list of names may not include all products that are available on the market.
Erectile dysfunction
Take sildenafil tablets exactly as your healthcare provider tells you. Your healthcare provider will tell you how much to take and when to take the medication. Take sildenafil tablets about 1 hour before sexual activity. You may take it between 30 minutes to 4 hours before sexual activity if needed. Sildenafil tablets can be taken with or without food.
Effectiveness and safety
If you take it after a high fat meal (such as a cheeseburger and french fries), it may take a little longer to start working Do not take sildenafil tablets more than 1 time a day. If you accidentally take too many sildenafil tablets, call your doctor or go to the nearest hospital emergency room right away. Do not take sildenafil tablets if you: take medicines called nitrates (such as nitroglycerin) use street drugs called “poppers” (such as amyl nitrate or amyl nitrite, and butyl nitrate) take any medicines called guanylate cyclase stimulators such as riociguat (Adempas®) are allergic to sildenafil, as contained in sildenafil tablets and REVATIO®, or any of the ingredients in sildenafil tablets. Sildenafil tablets can cause serious side effects. Stop taking sildenafil tablets and call your healthcare provider right away if you have sudden vision loss in one or both eyes.