Sildenafil, tadalafil, vardenafil and avanafil are phosphodiesterase type 5 inhibitors, usually shortened to PDE5 inhibitors. They are used for erectile dysfunction but differ in onset, duration and the way food or other medicines may influence them.
What they share: they support the erectile response by improving blood flow, but do not automatically create desire or an erection. Sexual stimulation is still required.
A simple comparison
| Active ingredient | Distinctive feature | Effect of food |
|---|---|---|
| Sildenafil | Well-known option generally taken in advance | A large meal may delay onset |
| Tadalafil | Longer window of action and prescribed daily options | Usually less affected by food |
| Vardenafil | Profile similar to sildenafil, with different formulations available | High-fat meals may delay onset |
| Avanafil | Designed for a relatively rapid onset | Food may delay the effect |
Timings in patient leaflets are guides rather than guarantees. Individual response, food, alcohol, health conditions and other medicines can change the result. “Faster” or “longer” does not automatically mean “better”.
How an appropriate option is chosen
The decision may consider frequency of sexual activity, desired spontaneity, previous side effects, other medicines and cardiovascular, kidney or liver conditions. A previous response can help guide a clinician, but does not make self-directed switching safe.
Shared precautions
- Do not combine two erectile dysfunction medicines.
- Do not use them with nitrates for angina or with riociguat.
- Mention treatment for blood pressure, prostate symptoms, HIV or fungal infections.
- Seek medical advice if sexual activity has been discouraged for heart-related reasons.
- Do not change the dose or frequency without professional guidance.
Possible side effects
Headache, flushing, indigestion and nasal congestion are common across the class. Tadalafil may also cause back or muscle pain. Sudden vision or hearing symptoms and a prolonged painful erection require medical attention.
Related guides: sildenafil explained and tadalafil duration and precautions.
