Essential BNF Information for Sildenafil Treatment
BNF Dosage Guidelines for Sildenafil
According to the British National Formulary, sildenafil is available in three strengths: 25mg, 50mg, and 100mg tablets. The typical starting dose is 50mg, taken approximately one hour before sexual activity. Based on individual response and tolerability, the dose may be adjusted to 25mg (if side effects occur) or increased to 100mg (if 50mg proves insufficient). The BNF emphasises that only one dose should be taken within any 24-hour period.
BNF Contraindications and Safety Warnings
The BNF lists several important contraindications for sildenafil. Patients taking nitrate medications (such as GTN spray or isosorbide mononitrate) must not use sildenafil due to potentially dangerous blood pressure drops. Other contraindications include severe cardiovascular disease, recent heart attack or stroke (within six months), severe liver impairment, and certain eye conditions. EverydayMeds offers both generic sildenafil and branded Viagra options, allowing patients to choose their preferred treatment following clinical assessment.
Drug Interactions Listed in BNF
The BNF highlights several significant drug interactions with sildenafil. Alpha-blockers used for prostate conditions may cause blood pressure reduction when combined with sildenafil. Certain antibiotics, antifungals, and HIV medications can increase sildenafil levels in the blood, potentially requiring dose adjustments. Patients should always inform their prescriber about all medications they're taking, including over-the-counter medicines and herbal supplements.
BNF Administration and Monitoring
According to BNF guidance, sildenafil should be taken on an empty stomach when possible, as fatty meals may delay absorption. The medication typically becomes effective within 30-60 minutes and effects may last up to four hours. However, this doesn't mean an erection will last this duration - sexual stimulation is still required for the medication to work. Regular monitoring may be necessary for patients with underlying health conditions or those taking multiple medications.
