| name | Sildenafil (Viagra) |
| classification | Phosphodiesterase 5 (PDE5) inhibitor |
| pharmacokinetics | | absorption | Rapidly absorbed after oral administration, with peak plasma concentrations typically achieved within 30-120 minutes. | | distribution | Distributed throughout the body, with high concentrations in the penis. | | metabolism | Primarily metabolized in the liver by the cytochrome P450 3A4 enzyme system. | | excretion | Excreted primarily in the urine as metabolites. |
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| suggested dosage | | initial | 50 mg, taken orally approximately 1 hour before anticipated sexual activity. | | typical maintenance | 50-100 mg, taken as needed, but not more than once per day. | | maximum dosage | 100 mg | | important notes | Individual dosage may vary based on patient response and tolerability. Always follow the prescribed dosage guidelines by a healthcare professional. |
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| indications | Treatment of erectile dysfunction (ED). |
| safety in pregnancy | Contraindicated. May cause fetal harm. Discontinue immediately and consult a healthcare professional if pregnancy occurs. |
| safety in breastfeeding | Limited data on excretion into breast milk. Consult a healthcare professional for a risk-benefit assessment before breastfeeding while using this medication. |
| side effects | | 1 | | | 2 | | | 3 | | | 4 | | | 5 | | effect | Visual disturbances (e.g., blue-tinted vision, blurred vision) |
| | 6 | | | 7 | | | 8 | | | 9 | | | 10 | | effect | Priapism (prolonged erection) - rare but serious: Seek immediate medical attention if this occurs. |
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| alternatives | |
| contraindications | | 1 | Hypersensitivity to sildenafil or formulation components. | | 2 | Severe heart conditions (e.g., unstable angina, recent myocardial infarction). | | 3 | Severe hypotension or hypertension. | | 4 | Retinitis pigmentosa. | | 5 | Concurrent use of certain medications (e.g., nitrates, alpha-blockers; check for potential interactions). | | 6 | History of prolonged erection. |
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| interactions | | 1 | | drug | Nitrates (e.g., nitroglycerin) | | interaction | Severe hypotension and potentially fatal cardiovascular events. |
| | 2 | | drug | Alpha-blockers | | interaction | Symptomatic hypotension. |
| | 3 | | drug | CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) | | interaction | Increased sildenafil levels, increased risk of side effects. |
| | 4 | | drug | CYP3A4 inducers (e.g., rifampicin) | | interaction | Decreased sildenafil levels, reduced effectiveness. |
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| warnings and precautions | | 1 | Careful monitoring in patients with pre-existing cardiovascular disease. | | 2 | Avoid excessive alcohol consumption. | | 3 | Do not use if currently taking nitrate medications or have a history of prolonged erections. | | 4 | Seek immediate medical attention for any signs of heart problems or visual disturbances. |
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| additional informations | | 1 | Use only as prescribed by a healthcare professional. | | 2 | Discuss underlying health conditions with your doctor before starting treatment. | | 3 | A thorough medical evaluation is necessary before prescribing to any male patient. |
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| patient specific information | | age | 25 | | weight | 70 | | notes | For a healthy 25-year-old male weighing 70 kg, the typical initial dosage and monitoring instructions apply as described in the suggested dosage section. Individualized recommendations remain crucial and should be discussed with a physician. |
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