What are the differences between sildenafil (Viagra) and tadalafil (Cialis) for erectile dysfunction (ED)?

From the Guidelines

Sildenafil and tadalafil are both effective for erectile dysfunction, but the choice between them should be based on individual preferences, including ease of use, cost, and side effect profile, as recommended by the American College of Physicians 1. The main differences between sildenafil (Viagra) and tadalafil (Cialis) lie in their duration of action, timing of use, and dosing frequency.

• Sildenafil typically works for 4-6 hours, making it ideal for planned sexual activity, while tadalafil can remain effective for up to 36 hours, allowing for more spontaneity.
• Sildenafil is usually taken 30-60 minutes before sexual activity at doses of 25-100mg, whereas tadalafil can be taken either as needed (10-20mg, 30 minutes before sex) or daily (2.5-5mg) for continuous coverage.
• Both medications work by inhibiting PDE5 enzymes, increasing blood flow to the penis during arousal, but tadalafil is more selective for PDE5 over other enzymes.
• Food interactions differ as well; high-fat meals can delay sildenafil's absorption and effectiveness, while tadalafil is less affected by food.
• Side effect profiles are similar, including headache, flushing, and indigestion, though tadalafil may cause more back pain and muscle aches. According to the AUA guideline, men with ED should be informed about the treatment options, including FDA-approved oral phosphodiesterase type 5 inhibitors (PDE5i), and the dose should be titrated to provide optimal efficacy 1. The evidence suggests that sildenafil, tadalafil, and vardenafil have similar efficacy in the general ED population, and the choice of medication should be based on individual preferences and side effect profiles 1. In summary, the decision between sildenafil and tadalafil should be based on individual preferences, including ease of use, cost, and side effect profile, and the medication should be used as directed, with the dose titrated to provide optimal efficacy, as recommended by the AUA guideline 1.

From the Research

Main Differences between Sildenafil and Tadalafil for ED

• Sildenafil (Viagra) and tadalafil (Cialis) are both phosphodiesterase type 5 (PDE5) inhibitors used to treat erectile dysfunction (ED) 2, 3.
• The main difference between the two is the duration of action, with tadalafil having a longer duration of action compared to sildenafil 4, 5.
• Sildenafil has a rapid onset of action, with effects seen within 30 minutes to 1 hour after dosing, while tadalafil has a slower onset of action, but its effects can last up to 36 hours 4, 5.

Pros and Cons of Sildenafil

• Pros:
  • Rapid onset of action 5
  • Effective in improving erections and allowing successful penetrative sexual intercourse 2, 6
  • Well-tolerated and safe for most patients 2, 6
• Cons:
  • Shorter duration of action compared to tadalafil 4, 5
  • May cause transient and mild to moderate adverse events such as headache, flushing, and dyspepsia 2, 6

Pros and Cons of Tadalafil

• Pros:
  • Longer duration of action compared to sildenafil 4, 5
  • Allows for more spontaneity in sexual activity 4, 5
  • Effective in improving erections and allowing successful penetrative sexual intercourse 3
• Cons:
  • Slower onset of action compared to sildenafil 5
  • May cause adverse events such as headache, flushing, and dyspepsia, although these are generally mild and transient 3

Note: There are no direct comparisons between sildenafil and tadalafil in the provided studies, but the information above is based on the available data on each medication.