Sildenafil citrate, the active ingredient in Viagra, works by increasing blood flow to the penis. This occurs through the inhibition of an enzyme called phosphodiesterase-5 (PDE5). PDE5 normally breaks down cGMP, a molecule that relaxes blood vessel walls. By blocking PDE5, sildenafil allows cGMP levels to rise, resulting in vasodilation and improved blood flow.
Dosage and Administration
The typical starting dose is 50mg, taken as needed, about an hour before sexual activity. Your doctor may adjust the dosage based on your response and individual needs. The maximum recommended dose is 100mg in a 24-hour period. Always follow your doctor’s instructions carefully. Sildenafil should be taken only when needed and not daily.
Possible Side Effects
Common side effects include headache, facial flushing, nasal congestion, and indigestion. More serious, though rare, side effects may include vision changes, hearing loss, and prolonged erection (priapism). Seek immediate medical attention if you experience any of these serious side effects. Inform your doctor about all medications you are currently taking before starting sildenafil, as interactions with other drugs are possible.
Who Shouldn’t Take Sildenafil?
Individuals with certain heart conditions, uncontrolled high blood pressure, or a history of stroke should avoid sildenafil. Those with severe liver or kidney disease, or those taking nitrates, should also not use this medication. Always consult your physician to determine if sildenafil is appropriate for you.
