| name | Sildenafil |
| classification | Phosphodiesterase 5 (PDE5) inhibitor |
| pharmacokinetics | | absorption | Rapidly absorbed after oral administration, with peak plasma concentrations typically reached within 30-120 minutes. | | distribution | Distributed throughout the body, with high concentrations observed in the penis, lungs, and liver. | | metabolism | Primarily metabolized by the cytochrome P450 3A4 enzyme system in the liver. | | excretion | Eliminated primarily in the urine as metabolites. |
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| suggested dosage | | initial | 50 mg taken orally approximately 30-60 minutes before anticipated sexual activity. | | adjustment | Dose can be adjusted based on individual response and tolerance, ranging from 25 mg to 100 mg, but not exceeding one 100 mg dose in 24 hours. A physician should always be consulted before making any changes to the prescribed dose. | | patient specific | Dosage should be tailored to the individual patient based on factors such as response, tolerance, and potential drug interactions. |
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| indications | Erectile dysfunction (ED). |
| safety in pregnancy | Not indicated for use in pregnant women. Potential harm to the fetus is a concern. Should not be used in pregnancy; pregnant women should not handle or have contact with sildenafil. |
| safety in breastfeeding | Limited data; potentially secreted into breast milk, but level unlikely to cause significant harm to infants. Consult a healthcare professional before use. |
| side effects | | 1 | Headache | | 2 | Flushing | | 3 | Nasal congestion | | 4 | Vision changes (e.g., blue-green tint) | | 5 | Dizziness | | 6 | Dyspepsia (indigestion) | | 7 | Myalgia (muscle pain) | | 8 | Back pain | | 9 | Priapism (prolonged erection): Although rare, this is a serious side effect and requires immediate medical attention. | | 10 | Hypotension (low blood pressure) |
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| alternatives | |
| contraindications | | 1 | Known hypersensitivity to sildenafil or any of its components. | | 2 | Concurrent use of nitrates (e.g., nitroglycerin). | | 3 | Severe cardiovascular disease (unstable angina, recent MI, severe hypotension). | | 4 | Retinitis pigmentosa or other retinal diseases. | | 5 | History of prolonged erection or priapism. |
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| interactions | | 1 | | drug | Nitrates | | effect | Potentially fatal interaction causing severe hypotension. |
| | 2 | | drug | Alpha-blockers | | effect | Potentially increased risk of hypotension; use with caution. |
| | 3 | | drug | CYP3A4 inhibitors | | effect | Increased sildenafil levels, potentially leading to increased side effects. |
| | 4 | | drug | CYP3A4 inducers | | effect | Decreased sildenafil levels, potentially reducing effectiveness. |
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| warnings and precautions | | 1 | Caution in patients with pre-existing cardiovascular conditions. | | 2 | Report any sudden changes in vision or hearing immediately. | | 3 | Inform patients about potential priapism and the need for immediate medical attention. | | 4 | Not for use in patients under 18 years old. | | 5 | Caution in patients with bleeding disorders. |
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| additional information | | 1 | Not suitable for patients with visual or hearing impairments. | | 2 | Advise against excessive alcohol consumption. | | 3 | Consult a healthcare professional before taking any other medications or supplements. |
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| patient information | |
