Sildenafil
Also known as Viagra
What it is
Sildenafil is a phosphodiesterase type 5 inhibitor with a shorter duration of action than tadalafil, taken on demand rather than daily.
How it is used
Taken orally roughly an hour before activity. A high-fat meal can delay onset. Dose is set by the prescriber and adjusted based on response and tolerance.
What a provider evaluates first
- Cardiovascular history and exercise tolerance
- Nitrate use — an absolute contraindication
- Other medications, particularly alpha-blockers
- Whether an underlying cause should be investigated
Considerations and monitoring
- Must never be combined with nitrates
- Onset can be delayed by a heavy meal
- Headache, flushing and visual disturbance are reported
Questions about sildenafil
Tadalafil or sildenafil — what is the difference?
Both are PDE5 inhibitors. Tadalafil has a much longer half-life, which allows either on-demand use or a lower daily dose; sildenafil is shorter-acting and taken on demand roughly an hour beforehand, with onset delayed by a heavy meal. Side-effect profiles differ slightly. Neither may be combined with nitrates under any circumstances. Which suits you is a clinical decision based on frequency of use, other medications and tolerance.
Can erectile dysfunction be a sign of something else?
Yes, and this is the reason evaluation matters. Erectile dysfunction is frequently an early marker of vascular disease, and can also reflect diabetes, low testosterone, medication side effects, sleep apnoea or psychological factors. Treating the symptom without assessing the cause can mean missing something more consequential. A provider will review cardiovascular risk factors and relevant laboratory work as part of the evaluation.
Part of Sexual Health.