The Science Behind BNF Sildenafil Treatment
How Sildenafil Works in the Body
Sildenafil, as detailed in the BNF (British National Formulary), belongs to a class of medications called PDE5 inhibitors. When a man becomes sexually aroused, nitric oxide is released in the penis, which increases levels of cyclic GMP. This chemical causes the smooth muscles in blood vessels to relax, allowing increased blood flow to the penis. The enzyme PDE5 normally breaks down cyclic GMP, but sildenafil blocks this process, helping to maintain the improved blood flow needed for an erection.
Clinical Mechanism and Onset
The BNF indicates that sildenafil typically becomes effective within 30-60 minutes of taking the tablet. The medication requires sexual stimulation to work - it doesn't cause automatic erections. Food, particularly fatty meals, may delay the onset of action. The effects can last for 4-6 hours, providing a window of opportunity for sexual activity, though this doesn't mean an erection will last this entire duration.
Dosage and Administration According to BNF Guidelines
The BNF recommends starting with a 50mg dose of sildenafil, taken approximately one hour before sexual activity. Depending on effectiveness and tolerability, this may be adjusted to 25mg or increased to a maximum of 100mg. Only one dose should be taken within any 24-hour period. EverydayMeds provides both branded Viagra and generic sildenafil in all BNF-approved strengths (25mg, 50mg, 100mg).
Who May Benefit from BNF Sildenafil
According to BNF guidance, sildenafil is suitable for adult men experiencing erectile dysfunction when prescribed following appropriate clinical assessment. Our UK-licensed prescribers evaluate cardiovascular health, current medications, and medical history to ensure safe prescribing. Patients can choose between branded Viagra or cost-effective generic sildenafil during checkout, as both contain the same active ingredient.
Important Safety Considerations
The BNF highlights several contraindications for sildenafil use. It must not be taken with nitrate medications (such as GTN spray) due to dangerous blood pressure interactions. Men with severe heart conditions, recent strokes, or significant liver problems may not be suitable candidates. Our clinical assessment process ensures these safety factors are carefully evaluated before prescribing either branded or generic options.
