Sildenafil drug bank

Need reliable information on Sildenafil? This guide provides direct access to key data points. We’ll examine its pharmacological profile, common uses, potential side effects, and crucial safety considerations. This isn’t an exhaustive analysis, but a focused resource for quick answers.

Sildenafil’s primary function is inhibiting phosphodiesterase type 5 (PDE5), resulting in increased blood flow, particularly beneficial for treating erectile dysfunction. Common dosages range from 25mg to 100mg, though individual needs vary; always consult a physician.

Potential side effects include headache, flushing, nasal congestion, and visual disturbances. Serious adverse events are rare but necessitate immediate medical attention. This guide emphasizes responsible use; self-medication is strongly discouraged. Always discuss Sildenafil use with your healthcare provider before starting treatment to ensure safe and appropriate application.

Drug interactions are a significant concern. Sildenafil interacts with nitrates and some other medications. Providing your doctor with a complete medication history is paramount to preventing harmful interactions and achieving optimal treatment results. This resource serves to expedite your understanding but cannot substitute professional medical counsel.

Sildenafil Drug Bank: A Detailed Overview

Consult your physician before using Sildenafil. This drug interacts with numerous medications, including nitrates. Ignoring this precaution may lead to serious health risks.

Understanding Sildenafil’s Mechanism

Sildenafil, the active ingredient in Viagra, works by inhibiting phosphodiesterase-5 (PDE5), an enzyme that breaks down cyclic GMP. This increased cyclic GMP leads to relaxation of smooth muscle in the penis, facilitating blood flow and achieving an erection.

• Key Action: PDE5 inhibition.
• Result: Improved blood flow to the penis.
• Important Note: Sexual stimulation is still required for Sildenafil to be effective.

Dosage and Administration

1. The typical starting dose is 50mg, taken orally as needed, about 1 hour before sexual activity.
2. Your doctor may adjust the dosage (25mg or 100mg) based on your response and tolerance.
3. Do not exceed the recommended dose without consulting your physician.

Common Side Effects

• Headache
• Facial flushing
• Nasal congestion
• Dyspepsia (indigestion)
• Visual disturbances (blurred vision, altered color perception)

Most side effects are mild and transient. Serious side effects are rare but require immediate medical attention.

Potential Drug Interactions

Sildenafil interacts with numerous medications, especially nitrates (used to treat angina). This combination can cause a dangerous drop in blood pressure.

Contraindications

• Patients with severe heart problems
• Patients with low blood pressure
• Patients with recent history of stroke or heart attack
• Patients taking nitrates
• Patients with certain eye conditions

This list is not exhaustive; always consult your doctor about your medical history before starting Sildenafil.

Further Information

Always refer to the official prescribing information for complete details and the most up-to-date information on Sildenafil. Your doctor can provide personalized guidance.

Disclaimer:

This information is for educational purposes only and should not be considered medical advice. Always consult your healthcare provider for any health concerns or before making any decisions related to your health or treatment.

Sildenafil: Mechanism of Action and Therapeutic Uses

Sildenafil selectively inhibits phosphodiesterase type 5 (PDE5), an enzyme that breaks down cyclic guanosine monophosphate (cGMP). Increased cGMP levels relax smooth muscle in the corpus cavernosum, facilitating blood flow and achieving an erection.

Its primary therapeutic use is treating erectile dysfunction (ED) in men. Sildenafil’s action directly addresses the physiological cause of ED, improving erectile function by enhancing penile blood flow.

Beyond ED, Sildenafil also finds application in treating pulmonary arterial hypertension (PAH). By relaxing blood vessels in the lungs, it reduces pulmonary vascular resistance, improving blood flow and easing symptoms.

Dosage for ED typically ranges from 25-100 mg, taken as needed. For PAH, dosage and administration vary significantly depending on individual needs and response; a physician’s guidance is paramount.

Important Considerations: Sildenafil interacts with nitrates, leading to potentially dangerous drops in blood pressure. Patients with certain cardiovascular conditions should avoid this drug. Consult your doctor before starting Sildenafil, especially if you have pre-existing health issues or take other medications.

Note: This information is for educational purposes only and does not constitute medical advice. Always seek professional medical guidance before starting any medication.

Pharmacokinetics of Sildenafil: Absorption, Distribution, Metabolism, and Excretion

Sildenafil absorption is rapid after oral administration, with peak plasma concentrations typically achieved within 30 to 120 minutes. Food slightly delays absorption but doesn’t significantly alter the extent of absorption.

Sildenafil is extensively distributed throughout the body, with high concentrations found in the lungs and penis. Approximately 96% binds to plasma proteins.

Metabolism

The liver primarily metabolizes sildenafil, predominantly via the cytochrome P450 isoenzyme CYP3A4, although CYP2C9 also plays a role. The major metabolite, N-desmethyl sildenafil, also exhibits PDE5 inhibitory activity, though less potent than sildenafil itself. This metabolic pathway is important to consider when co-administering sildenafil with other drugs metabolized by these enzymes.

Excretion

Sildenafil and its metabolites are eliminated primarily via the feces (approximately 80%) and urine (approximately 13%). The terminal elimination half-life is approximately 4 hours. This relatively short half-life means effects generally subside within a few hours.

Pharmacokinetic Variations

Significant inter-individual variability exists in sildenafil pharmacokinetics. Age, liver and kidney function, and concomitant medications all influence drug levels. Consult prescribing information for specific considerations.

Parameter	Value/Characteristic
Absorption	Rapid; peak plasma concentrations in 30-120 minutes; food delays but doesn’t drastically reduce absorption
Distribution	Extensive; high lung and penis concentrations; 96% plasma protein binding
Metabolism	Primarily hepatic; CYP3A4 and CYP2C9; major metabolite (N-desmethyl sildenafil) retains PDE5 inhibitory activity
Excretion	Primarily fecal (80%), urinary (13%); half-life ~4 hours

Clinical Implications

Understanding sildenafil’s pharmacokinetics guides appropriate dosing and allows for better prediction of drug interactions. Always consult relevant guidelines and patient-specific factors for optimal therapeutic outcomes.

Common Side Effects and Adverse Reactions of Sildenafil

Sildenafil, while generally safe, can cause side effects. Headache is the most common, affecting a significant percentage of users. Facial flushing, a feeling of warmth or redness in the face, neck, and chest, is another frequently reported side effect. Nasal congestion, or a stuffy nose, is also relatively prevalent.

Gastrointestinal Effects and Visual Disturbances

Some users experience indigestion, upset stomach, or diarrhea. Less frequently, visual disturbances such as blurred vision, changes in color perception, or increased light sensitivity may occur. These visual effects are usually mild and temporary. It’s important to note that these side effects vary in intensity and frequency among individuals.

Less Common Side Effects

Back pain, muscle aches, and dizziness are reported less often. In rare cases, more serious side effects like prolonged erection (priapism), hearing loss, or vision loss can occur. Seek immediate medical attention if you experience any prolonged or severe side effects. Always consult your doctor before starting sildenafil, especially if you have pre-existing health conditions.

Drug Interactions with Sildenafil: Medications to Avoid

Avoid combining sildenafil with nitrates, such as nitroglycerin. This combination can cause a dangerous drop in blood pressure, potentially leading to serious health issues. Consult your doctor before taking sildenafil if you use any heart medications.

Alpha-blockers, often prescribed for high blood pressure or prostate problems, can also interact negatively with sildenafil. This combination may lead to significant dizziness or low blood pressure. Discuss your medications with your doctor to determine compatibility.

Certain antifungals, particularly ketoconazole and itraconazole, can increase sildenafil levels in your body. This can heighten the risk of side effects. Your physician can help you manage this interaction safely.

CYP3A4 inhibitors, including some antibiotics like erythromycin and clarithromycin, can also interact with sildenafil, potentially raising its concentration in your blood. This interaction needs careful monitoring by your doctor.

Always inform your doctor and pharmacist about all medications, supplements, and herbal remedies you are taking before starting sildenafil. This allows them to assess potential interactions and adjust your treatment plan accordingly to ensure your safety.

This information is for general knowledge and does not replace professional medical advice. Consult your healthcare provider for personalized guidance regarding sildenafil and its interactions with your specific medications.

Contraindications and Precautions for Sildenafil Use

Avoid sildenafil if you have a history of heart attack, stroke, or life-threatening arrhythmias. This includes individuals with unstable angina or uncontrolled hypertension.

Patients with severe liver or kidney disease should exercise caution and potentially require lower doses, as sildenafil metabolism is affected. Your doctor will assess your suitability.

Concurrent use with nitrates (e.g., nitroglycerin) is strictly prohibited due to the risk of severe hypotension. This combination can cause a dangerous drop in blood pressure.

Specific Medications and Interactions

Sildenafil interacts with several medications. Alpha-blockers, commonly used to treat high blood pressure, can synergistically lower blood pressure when combined with sildenafil. Similarly, the interaction with certain HIV protease inhibitors can increase sildenafil plasma concentrations. Always inform your doctor about all medications you take.

Other Precautions

Individuals with retinitis pigmentosa should avoid sildenafil due to potential vision problems. Similarly, those with a history of priapism (prolonged erection) should also avoid its use. Patients with anatomical penile deformation should seek medical advice before use.

Be aware that sildenafil can cause visual disturbances, such as changes in color vision, blurred vision, or increased light sensitivity. If these occur, discontinue use and consult your doctor.

Sildenafil Dosage and Administration Guidelines

The recommended starting dose of sildenafil for erectile dysfunction is 50 mg taken orally as needed, approximately one hour before sexual activity. This dose may be increased to 100 mg or decreased to 25 mg based on individual response and tolerability. Do not exceed 100 mg in a 24-hour period.

For pulmonary arterial hypertension, the dosage varies significantly depending on the patient’s condition and response to treatment. Your physician will determine the appropriate starting dose and titration schedule, which will likely involve gradual increases in dosage until an optimal response is achieved or side effects become limiting.

Sildenafil should be taken with a glass of water. Food may slightly delay absorption, but it generally does not significantly affect efficacy. Avoid grapefruit or grapefruit juice, as they can interact negatively and increase sildenafil’s concentration in your blood.

Always follow your doctor’s instructions precisely regarding dosage and frequency. If you miss a dose, do not take an extra dose; simply take your next dose as scheduled. If you experience side effects, contact your healthcare provider immediately.

This information is for guidance only and does not substitute for professional medical advice. Consult your physician or pharmacist for any questions or concerns about sildenafil administration.