How does sildenafil citrate tablets work

Most of these side effects may go away within a few days or a couple of weeks. Call your doctor right away if you have serious side effects. You may wonder how often certain side effects occur with this drug.

As with most drugs, some people can have an allergic reaction after taking Viagra. A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:. Call your doctor right away if you have a severe allergic reaction to Viagra.

Rarely, Viagra can cause priapism , which is a long-lasting and sometimes painful erection. Priapism is a medical emergency that needs to be treated right away. If you have an erection that lasts longer than 4 hours, go to the nearest emergency room or call Viagra can temporarily lower your blood pressure after you take the drug.

But keep in mind that a sudden drop in your blood pressure could be dangerous if you have certain heart conditions. You should also avoid taking Viagra if you take a drug called riociguat Adempas. Taking Viagra with these medications can cause a dangerous drop in your blood pressure that leads to heart attack or stroke. If you have low blood pressure, taking Viagra could make you feel dizzy or lightheaded, or cause you to faint.

If you feel dizzy or faint after taking Viagra, lie down until this feeling passes. If you have a heart problem or low blood pressure, talk with your doctor about whether Viagra is safe for you. On rare occasions, some people taking Viagra have had heart attack , stroke , or irregular heartbeat. These conditions mainly occurred in people who already had a heart problem. If you have chest pain after taking Viagra, you should stop having sexual activity right away.

And if you have a heart problem, talk with your doctor before starting Viagra. Headaches are a common side effect of Viagra. Headaches, as well as flushing and dizziness, occur because Viagra widens certain blood vessels in your body. This percentage varied depending on the dose of Viagra used and how often the drug was taken. If you have a headache after taking Viagra, it should go away fairly quickly.

Men ages 65 years and older tend to get higher levels of Viagra in their blood after taking a dose than younger men do. Having a higher level of the drug in your body could increase your risk of side effects. However, Viagra can sometimes cause priapism , which is a long-lasting and sometimes painful erection. If you have an erection that lasts longer than 4 hours, you should immediately go to an emergency room or call Most of the mild side effects of Viagra either tend to go away within a few hours of taking your dose or can be easily relieved.

For example, headaches, flushing, and dizziness can often be eased by lying down and resting. Avoiding alcohol will also help reduce these side effects. Headaches and sensitivity to light can also be improved by turning off any bright lights around you.

If you get indigestion after taking Viagra, try taking your dose of Viagra with a snack or light meal. Just be aware that if you do this, Viagra may take slightly longer to start working for you.

This is especially true if you eat a high-fat meal with your dose. If your indigestion is bothersome, ask your doctor or pharmacist to recommend medication to help reduce your discomfort. Also keep in mind that certain side effects occur more often with higher doses of Viagra.

These side effects include headaches, flushing, indigestion, nasal congestion, and changes in your vision.

So if these side effects are a problem for you, talk with your doctor about taking a lower dosage of Viagra. For example, you should call your doctor right away if you have:. The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you.

Your doctor will determine the best dosage to fit your needs. The typical dose of Viagra for erectile dysfunction ED is 50 mg. You can take this dose 30 minutes to 4 hours before you plan to have sexual activity. Your doctor may prescribe a different dosage of Viagra for you depending on several factors.

If any of these factors apply to you, your starting dose might be 25 mg, which is lower than the typical recommended dose. But the maximum dose of Viagra is mg. For example, people ages 65 years and older tend to get higher levels of Viagra in their blood after taking a dose. For example, they may recommend that you take 25 mg of the drug rather than 50 mg. Viagra is a prescription medication that can have serious side effects.

If you and your doctor determine that Viagra is safe and effective for you, you can likely take it for as long as you continue to need it. Other drugs are available that can treat erectile dysfunction ED. Some may be a better fit for you than others. They can tell you about other medications that may work well for you. Natural and over-the-counter OTC products for treating ED are widely available, especially on the internet.

This includes products that contain these ingredients either alone or in combination with other ingredients. And these products may cause harmful side effects. Examples of products that contain one or more of these ingredients include Libido-Max and Extenze.

You should also avoid products you can buy online without a prescription that claim either to be generic forms of sildenafil or to contain sildenafil. Sildenafil is the active drug in Viagra. You may wonder how Viagra compares with other medications that are prescribed for similar uses.

Here we look at how Viagra and Cialis are alike and different. Viagra contains the drug sildenafil , while Cialis contains the drug tadalafil. A class of drugs is a group of medications that work in a similar way.

Viagra and Cialis are both approved to treat erectile dysfunction ED in males ages 18 years and older. In addition, Cialis is approved to treat symptoms caused by benign prostatic hyperplasia BPH. They can also include having a weak flow of urine or being unable to fully empty your bladder. While you can take Cialis just as needed for ED treatment, another option is to take a low dose of the drug regularly each day. This may help make sex more spontaneous for you.

Viagra and Cialis both contain the same type of drug. Therefore, these medications can cause very similar side effects. Below are examples of these side effects. These lists contain up to 10 of the most common mild side effects that can occur with Viagra, with Cialis, or with both drugs when taken individually.

The following list contains examples of serious side effects that can occur with either Viagra or Cialis. The use of Viagra and Cialis in treating ED has been directly compared in several clinical studies. However, researchers found that men who took Cialis had improved confidence in their sexual ability. So the men were more likely to prefer Cialis over Viagra. This is likely due to the long-lasting effect of Cialis, which allows men to have more spontaneous sex. The study also found that men who took Cialis were more likely to have back or muscle pain than were men taking Viagra.

But men taking Cialis were less likely to have flushing compared with men taking Viagra. Viagra and Cialis are both brand-name drugs.

Generic forms of both drugs are available. Brand-name medications usually cost more than generics. According to estimates on GoodRx. Here we look at how Viagra and sildenafil are alike and different.

Viagra, which contains the active drug sildenafil, is a brand-name drug. But sildenafil is also available as a generic medication. A generic medication is an exact copy of the active drug in a brand-name medication. Viagra is approved to treat erectile dysfunction ED in males ages 18 years and older. It comes as tablets that are taken by mouth. But if you have certain medical conditions or are taking other drugs, your doctor may recommend that you take this drug less often than once a day.

Sildenafil can be taken with food or without food. It is important to note that certain foods, particularly foods high in fat, can cause the drug to work more slowly than normal. If these effects are mild, they may go away within a few days or a couple of weeks.

Call your doctor right away if you have serious side effects. Serious side effects and their symptoms can include the following:. Sildenafil oral tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works.

This can be harmful or prevent the drug from working well. To help avoid interactions, your doctor should manage all of your medications carefully. Do not take these drugs with sildenafil. Doing so can cause dangerous effects in the body. Examples of these drugs include:. Side effects from sildenafil: Taking sildenafil with certain medications raises your risk for side effects from sildenafil. This is because the amount of sildenafil in your body is increased.

Side effects from other drugs: Taking sildenafil with certain medications raises your risk for side effects from these drugs. Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions.

This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking. Taking it again could be fatal cause death. The use of drinks that contain alcohol raises your risk for low blood pressure from sildenafil. If you drink alcohol, talk with your doctor. You may need to have your blood pressure monitored while you take this drug.

For people with heart problems: This drug can lower your blood pressure. These problems include a heart attack, stroke, or life threatening heart rhythm problem. Also talk with your doctor if you have a low or high resting blood pressure, or a history of heart failure or coronary artery disease.

For people with pulmonary veno-occlusive disease PVOD : Taking this drug may worsen your heart function. You should not take this drug. For people with eye problems: This drug may cause sudden loss of vision in one or both eyes. For people with a history of stomach ulcers or bleeding: This drug raises your risk for stomach bleeding, ulcers, or small holes in the lining of your digestive system.

These events can be fatal cause death. They can happen at any time, with or without symptoms. For people with sickle cell anemia: This drug may cause a common painful complication of sickle cell anemia called vaso-occlusive crisis. Viagra sildenafil is a prescription drug used to treat erectile dysfunction ED in men.

Instead, it relaxes muscles and increases blood flow to cause an erection. Manufactured by Pfizer, Viagra is a brand name for the generic medication sildenafil citrate.

The U. Sildenafil may also treat pulmonary arterial hypertension. Viagra is a vasodilator that is only available by prescription. Viagra more about Viagra works by relaxing muscles in blood vessel walls to help increase blood flow to the penis, making it easier to get and maintain an erection. Viagra is only effective if there is sexual stimulation, such as that occurring during sexual intercourse.

When stimulation first happens, Viagra helps increase blood flow to the penis and then works to help maintain an erection. Viagra is a type of erectile dysfunction drug called a phosphodiesterase 5 inhibitor. PDE5 inhibitors keep a particular enzyme called phosphodiesterase type-5 PDE5 from acting too quickly.

Viagra will not be as effective for people with certain conditions. You may not get the full benefits of Viagra if you are sick, fatigued, or intoxicated. Alcohol can worsen the side effects of viagra and potentially make erectile dysfunction worse.

You should take Viagra on an empty stomach about one hour before sex. It starts working within 30 to 60 minutes, but an erection requires sexual stimulation. In most patients, the effects of Viagra will last for up to two hours. A duration of two hours or less indicates that an appropriate dose was taken. If the duration is greater than four hours, medical attention should be sought out immediately to avoid damaging effects on the tissues.

In case of overdose, call the poison control helpline at If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at Do not let anyone else take your medication.

Ask your pharmacist any questions you have about refilling your prescription. It is important for you to keep a written list of all of the prescription and nonprescription over-the-counter medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital.

It is also important information to carry with you in case of emergencies. Sildenafil pronounced as sil den' a fil. Why is this medication prescribed?

How should this medicine be used? Other uses for this medicine What special precautions should I follow? What special dietary instructions should I follow? What should I do if I forget a dose? What side effects can this medication cause? What should I know about storage and disposal of this medication? Brand names. Sildenafil comes as a tablet and suspension liquid; Revatio only to take by mouth.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient. Other uses for this medicine. What special precautions should I follow? Before taking sildenafil, tell your doctor and pharmacist if you are allergic to sildenafil, any other medications, or any of the ingredients in sildenafil products. Ask your pharmacist for a list of the ingredients.

Nitrates come as tablets, sublingual under the tongue tablets, sprays, patches, pastes, and ointments. Ask your doctor if you are not sure whether any of your medications contain nitrates.

Be sure to mention any of the following: alpha blockers such as alfuzosin Uroxatral , doxazosin Cardura , prazosin Minipress , tamsulosin Flomax, in Jalyn , and terazosin; amlodipine Norvasc, in Amturnide, in Tekamlo ; certain antifungals such as itraconazole Onmel, Sporanox and ketoconazole Nizoral ; anticoagulants 'blood thinners' such as warfarin Coumadin, Jantoven ; certain barbiturates such as butalbital in Butapap, in Fioricet, in Fiorinal, others and secobarbital Seconal ; beta blockers such as atenolol Tenormin, in Tenoretic , labetalol Trandate , metoprolol Lopressor, Toprol XL, in Dutoprol , nadolol Corgard, in Corzide , and propranolol Hemangeol, Inderal LA, InnoPran ; bosentan Tracleer ; cimetidine ; efavirenz Sustiva, in Atripla ; erythromycin E.