Currently, there are four different pills that are prescribed for erectile dysfunction (ED):
• Sildenafil (Viagra)
• Vardenafil (Levitra or Staxyn)
• Tadalafil (Cialis)
• Avanafil (Stendra)
All of these medications are phosphodiesterase type 5 (PDE5) inhibitors and allow more blood flow to the penis.
Basically, all four medications work the same way, but have slightly different ingredients. So, their results vary. For example, Viagra may be effective for up to five hours, but a version of Cialis may work for up to three days. Some medications are taken with food; some are not. They might also have different side effects. A doctor can help make the right choice.