Clinical Guidelines and Prescribing Information
BNF Dosage and Administration
According to BNF guidelines, sildenafil for erectile dysfunction is available in 25mg, 50mg, and 100mg tablets. The recommended starting dose is typically 50mg, taken approximately one hour before sexual activity. Based on effectiveness and tolerability, the dose 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 sildenafil (generic) and Viagra (branded) formulations at these standard strengths.
Contraindications and Cautions
The BNF clearly outlines important contraindications for sildenafil use. Patients taking nitrate medications (such as GTN spray or isosorbide mononitrate) must not use sildenafil due to potentially dangerous hypotensive effects. Other contraindications include severe cardiovascular disease, recent myocardial infarction or stroke within six months, severe hepatic impairment, and hypotension. Patients with hereditary degenerative retinal disorders or known hypersensitivity to sildenafil should also avoid treatment.
Drug Interactions and Monitoring
BNF guidance emphasises several significant drug interactions requiring careful consideration. Alpha-blockers may enhance hypotensive effects, whilst CYP3A4 inhibitors like ketoconazole or ritonavir can increase sildenafil plasma concentrations. Concurrent use with other PDE5 inhibitors is contraindicated. Healthcare professionals should review all current medications during clinical assessment to identify potential interactions.
Clinical Assessment Requirements
Before prescribing sildenafil, a comprehensive clinical assessment is mandatory. This includes evaluation of cardiovascular status, current medication review, and assessment of underlying causes of erectile dysfunction. EverydayMeds ensures all patients complete this assessment with UK-licensed prescribers before treatment initiation. Patients can then choose between generic sildenafil or branded Viagra based on personal preference and budget considerations.
