sildenafil

medtigo

sildenafil

Brand Name :

Revatio, Viagra

Synonyms :

sildenafil

Class :

Phosphodiesterase-5 Enzyme Inhibitors; PAH, PDE-5 Inhibitors;

Action and Spectrum

Actions and Spectrum:

sildenafil is a medication that is primarily used to treat erectile dysfunction (ED) in men. It works by relaxing the blood vessels in the penis, allowing for increased blood flow and improved ability to achieve and maintain an erection.

Aside from treating ED, sildenafil can also be used to treat pulmonary arterial hypertension (PAH), a condition characterized by high blood pressure in the arteries that supply the lungs. In PAH, sildenafil helps to relax the blood vessels in the lungs, allowing for improved blood flow and reduced blood pressure.

The spectrum of sildenafil is relatively narrow, as it primarily acts on the blood vessels in the penis and lungs. However, it may also have some effects on other parts of the body, such as the heart and blood vessels in other areas.

Dosing & Uses

Drug Interaction

Adverse Reaction

Frequency defined

>10%

Headache

Flushing

Headache

Flushing

Dyspepsia

Abnormal vision

1-10%

Dyspepsia

Nasal congestion

Back pain

Dizziness

Nausea

Abnormal vision

Myalgia

Rash

<1%

Flushing

Epistaxis

Diarrhea

Insomnia

Myalgia

Dyspnea exacerbates

Erythema

Pyrexia

Rhinitis

Gastritis

Sinusitis

Paresthesia

Black Box Warning

Contraindication / Caution

Contraindication/Caution:

Contraindications:

sildenafil should not be taken by individuals who are taking nitrates, such as nitroglycerin, as the combination can cause a dangerous drop in blood pressure.
It should also not be taken by individuals who are allergic to sildenafil or any of its components.

Caution:

Individuals who have a history of heart disease, high or low blood pressure, or liver or kidney problems should use sildenafil with caution and under the guidance of a doctor.
sildenafil may interact with certain medications, including those used to treat HIV or fungal infections, so it is important to discuss all medications with a doctor before taking sildenafil.
sildenafil may not be safe for individuals with certain eye conditions, such as retinitis pigmentosa.
Individuals who experience an erection lasting longer than four hours, or sudden loss of vision or hearing, should seek medical attention immediately.
sildenafil should not be taken with alcohol, as it can increase the risk of side effects and reduce the effectiveness of the medication.

Pregnancy / Lactation

Pregnancy consideration:

Not recommended to be used in pregnant women

Breastfeeding warnings:

It is excreted in breastmilk, hence not recommended to be used in lactating women

Pregnancy category:

Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester.
Category B: No evidence shown of risk to the fetus found in animal reproduction studies, and there are not enough studies on pregnant women
Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for a product in humans; Pregnant women must take care of the potential risks.
Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms. However, despite potential dangers may be used only in emergency cases for potential benefits.
Category X: Drugs listed in this category outweigh risks over benefits. The drug is not for pregnant women.
Category N: No data is available for the drug under this category.

Pharmacology

Pharmacology:

sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor, which means it works by blocking the action of the PDE5 enzyme. PDE5 is responsible for breaking down cyclic guanosine monophosphate (cGMP), a molecule that helps to relax the smooth muscles in the blood vessels, including those in the penis and lungs.

When sildenafil is taken, it inhibits the PDE5 enzyme, allowing for increased levels of cGMP in the blood vessels. This leads to relaxation of the smooth muscles and increased blood flow to the penis, which helps to improve erectile function. In the lungs, increased cGMP levels result in relaxation of the blood vessels and reduced blood pressure, which helps to treat pulmonary arterial hypertension (PAH).

sildenafil is rapidly absorbed into the bloodstream after oral administration and reaches peak plasma concentrations within 30-120 minutes. It is metabolized in the liver and excreted mainly in the feces, with a small amount excreted in the urine. The half-life of sildenafil is approximately 4 hours, which means that it is eliminated from the body relatively quickly

Pharmacodynamics:

The pharmacodynamics of sildenafil refers to how the drug works in the body and its effects on various physiological processes.

As a PDE5 inhibitor, sildenafil increases the levels of cyclic guanosine monophosphate (cGMP) in the blood vessels, which leads to smooth muscle relaxation and increased blood flow. In the penis, this results in improved erectile function, while in the lungs, it helps to reduce pulmonary arterial hypertension (PAH) by relaxing the blood vessels and lowering blood pressure.

In addition to its effects on cGMP, sildenafil may also have some effects on other pathways in the body. For example, it may increase the release of nitric oxide, a signaling molecule that plays a role in regulating blood vessel function. It may also affect other PDE enzymes, such as PDE3, which are involved in regulating heart and cardiovascular function.

Pharmacokinetics:

Absorption

The bioavailability is 40%

Distribution

The peak plasma time is 30-120 min

Metabolism

Drug is metabolized in the liver by CYP3A4 and CYP2C9

Metabolite formed is N-desmethyl

Elimination and Excretion

The half-life is 3-4 hour for parent drug and for active metabolite is 10-70 minutes

The drug is excreted 80% in feces and 13% in urine

Adminstartion

Administration:

sildenafil is typically administered orally in the form of tablets or capsules. The dose and frequency of administration depend on the condition being treated and individual factors such as age and health status.

For the treatment of erectile dysfunction, the recommended starting dose of sildenafil is usually 50 mg taken approximately 1 hour before sexual activity. The dose may be adjusted based on the individual’s response and tolerability, up to a maximum dose of 100 mg per day. sildenafil should not be taken more than once per day.

For the treatment of pulmonary arterial hypertension (PAH), the recommended dose of sildenafil is typically 20 mg three times per day, with a maximum dose of 80 mg per day.

sildenafil should be taken on an empty stomach, as food can delay the absorption and reduce the effectiveness of the drug. It should be swallowed whole with a full glass of water.

It is important to follow the dosing instructions provided by a healthcare provider and not to exceed the recommended dose. Taking too much sildenafil can increase the risk of side effects, including headache, flushing, and low blood pressure.

sildenafil should not be taken with nitrates, as this combination can cause a dangerous drop in blood pressure. It should also not be taken with certain medications, such as alpha-blockers and certain antifungal medications, without the guidance of a healthcare provider.

Patient Information Leaflet

Patient information leaflet

Generic Name: sildenafil

Pronounced: sil-DEN-a-fil

Why do we use sildenafil?

sildenafil is primarily used to treat two main conditions:

Erectile dysfunction: sildenafil is commonly used to treat erectile dysfunction (ED) in men, which is the inability to achieve or maintain an erection sufficient for sexual activity. Sildenafil works by increasing blood flow to the penis, which helps to improve erectile function.
Pulmonary arterial hypertension: sildenafil is also used to treat pulmonary arterial hypertension (PAH), which is a condition characterized by high blood pressure in the blood vessels of the lungs. sildenafil works by relaxing the blood vessels in the lungs, which helps to reduce blood pressure and improve blood flow.

sildenafil

No data available for drug.

DRUG INTERACTION

sildenafil

&

sildenafil +

Contraindicated

Serious Use Alternative

Monitor Closely

Minor

sildenafil

No data available for drug.

DRUG INTERACTION

sildenafil

&

sildenafil +

Contraindicated

Serious Use Alternative

Monitor Closely

Minor

medtigo

sildenafil

Brand Name :

Synonyms :

Class :

Action and Spectrum

Dosing & Uses

Drug Interaction

Adverse Reaction

Black Box Warning

Contraindication / Caution

Pregnancy / Lactation

Pharmacology

Adminstartion

Patient Information Leaflet