Sildenafil is a prescription drug used to treat erectile dysfunction that comes in the form of a tablet. It’s available as the brand-name drugs Viagra and Revatio or as a generic drug. Brand-name drugs typically cost much more than generic drugs with little research to warrant the dramatic price increase.
Sildenafil Mechanism of Action
Sildenafil works by blocking phosphodiesterase (PDE5), an enzyme that promotes the breakdown of cGMP (cyclic guanosine monophosphate), which regulates blood flow to the penis. As a result, it allows cGMP to elicit smooth muscle relaxation that facilitates relief in pulmonary arterial hypertension and the increased flow of blood into the “spongy” erectile tissue of the penis. This allows it to grow in size and become erect.
How Long Does It Take For Sildenafil To Work?
Sildenafil may take up to one hour before it “kicks in.” It is recommended that you take sildenafil between 30 minutes to 4 hours before sex.
Sildenafil Uses
Sildenafil is most often used to prevent and treat erectile dysfunction.
How Long Does Sildenafil Last?
The length of time that sildenafil can last depends on your age, weight, and overall health. The general consensus, however, is that the pill usually wears off after 4-6 hours.
How Much Sildenafil is Too Much?
Sildenafil is prescribed for ED at 20 mg for a single dose all the way up to 100 mg in a single dose. Do not take higher doses than prescribed. Doing so may result in an unsafe drop in blood pressure or worse. Do not take more than is prescribed in any 24-hour period.
Can I Take Sildenafil With Food?
Sildenafil can be taken with food or on an empty stomach. It is important to note, however, that foods high in fat may cause the drug to work more slowly than normal.
Side Effects of Sildenafil
Sildenafil may come with a few potential side effects. It does not cause drowsiness. Potential side effects include:
• Headaches
• Nosebleeds
• Upset stomach
• Flushing (warming and/or reddening of the face)
• Trouble sleeping
• Fever
• Nausea
• Vomiting
• Bronchitis
• Sore throat
• Runny nose/stuffy
Many of these effects are mild and may go away within a few days or possibly a couple of weeks. If you are unsure of the severity of the side effects don’t hesitate to talk with your doctor or pharmacist.
Serious Side Effects
Contact your doctor or call 911 right away if you feel like your symptoms are life threatening. Serious side effects may include:
• Blurred vision
• Confusion
• Dizziness
• Fainting
• Lightheadedness
• Nausea or vomiting
• Weakness
• Increased shortness of breath
• Priapism (a painful erection that last for more than 4 hours)
• Sudden vision loss in one or both eyes
Hearing problems. Symptoms may include:
• Sudden hearing loss
• Tinnitus (ringing in your eyes)
Heart problems, such as stroke, irregular heart rate, or heart attack.
• Chest pain
• Shortness of breath
• Dizziness
• Trouble speaking
• Feeling lightheaded
• Confusion
Sildenafil Warnings
Vision loss warning: Sildenafil may cause vision loss in both or just one eye. If this persist, contact your doctor or pharmacist right away.
Priapism warning: Priapism is a painful erection that won’t go away and can persist for longer than 4 hours. If you experience this call 911 or go to the nearest emergency room right away. If not treated immediately, this condition may cause serious and permanent damage to your penis.
Hearing loss warning: This drug can cause hearing loss or tinnitus—which is ringing in your ears. If you have sudden hearing loss, contact your doctor right away.
Warning for use in children: As a general rule, children should not take sildenafil. There are a few instances, however, where this drug is considered the best treatment option.
Sildenafil Interactions
Sildenafil may interact with other medications and/or vitamins that you are taking. By interaction, we mean when a substance changes the way a drug works. Be sure to communicate with your healthcare professional about all the medications or supplements you are currently taking.Drugs You Should Not Take With Sildenafil
Nitrates: This includes isosorbide mononitrate, isosorbide dinitrate, or nitroglycerin. Taking sildenafil while you are taking nitrates may cause your blood pressure to drop precipitously to dangerous levels.
Guanylate cyclase stimulators: Taking these drugs like riociguat, can cause your blood pressure to drop very quickly to unsafe levels.
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.
What Can Increase Your Risk For Side Effects There are certain medications that can increase your risk of experiencing side effects from sildenafil. Examples of these drugs include:• Alpha-blockers
• Blood pressure drugs like amlodipine
• Other drugs for ED such as avanafil or tadalafil.
Warnings For Preexisting Health Conditions
Heart problems: Sildenafil can lower your blood pressure. If you have had heart complications in the past, ask your doctor if this drug is right for you.
Eye problems: This drug can cause sudden loss of vision in both or only one eye. If you have a history of eye problems talk to your healthcare professional.
Pulmonary veno-occlusive disease (PBOD): This is a rare form of pulmonary hypertension. You should not take this drug if you have PBOD for it may worsen your heart function.
Sickle cell anemia: Sildenafil may cause a painful complication of sickle cell anemia referred to as vaso-occlusive crisis. If you have sickle cell anemia, ask your doctor if this drug is safe for you.
Sildenafil Dosage
Your dosage depends on a few different things:
• Your health
• Your age
• How severe your condition is
• Other medical conditions you may have
• How you react to the medication
Dosage For ED
Generic: Sildenafil
• Form: Oral tablet
• Strengths: 25 mg, 50 mg, 100 mg
Brand: Viagra
• Form: Oral tablet
• Strengths: 25 mg, 50 mg, 100 mg
This drug has not been confirmed to be safe or effective in children younger than 18 years of age.
Dosage For PAH (Pulmonary Arterial Hypertension)
Generic: Sildenafil
• Form: Oral tablet
• Strengths: 20 mg
Brand: Revatio
• Form: Oral tablet
• Strengths: 20 mg
This drug should not be used in children younger than 18 years of age.
Disclaimer: Our goal at ManifestRX is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.
How To Tell If It’s Working
If the drug is working properly, you should be able to get and keep an erection when sexually aroused. For PAH (pulmonary arterial hypertension), you should be able to exercise more easily, and your doctor will also check in on you to ensure the drug is working effectively.
Summary
Sildenafil is a prescription drug used to treat erectile dysfunction that comes in the form of a tablet. It’s available as the brand-name drugs Viagra and Revatio or as a generic drug.
Sildenafil works by blocking phosphodiesterase (PDE5), an enzyme that promotes the breakdown of cGMP (cyclic guanosine monophosphate), which regulates blood flow to the penis.
Be sure to speak to your pharmacist or doctor and see if sildenafil is right for you.
