tadalafil

Last reviewed 01/2018

Tadalafil is a phosphodiesterase type 5 inhibitor (PDE5), like sidenafil.

• the Summary of Product Characteristics states that (1):
  • men should be started on a dose of 10mg, taken at least 30 minutes prior to sexual activity
  • if the 10mg dose does not produce an adequate effect then the dose can be increased to 20mg
  • the maximum dosing is once daily - the mean half-life is 17.5 hours
  • continuous daily dosing is discouraged - safety of prolonged daily dosing has not been established
  • the Summary of Product Characteristics recommends a dose of 10mg for men with "impaired hepatic function" and a maximum dose of 10mg for those with "severe renal impairment"
• focusing on its phase II/III trial results, tadalafil appears to have an enhanced period of responsiveness extending out to 36 hours in 60% of men using the 20 mg dose. Efficacy across a large population of men with erectile dysfunction (ED) of various causes (n = 1112) is in accordance with the other PDE5 inhibitors at 81% (1). Side effects are generally mild-to-moderate with study drop-out rate at 1.7% in the active arm compared to 1.1% among those receiving placebo (2)

The summary of product characteristics must be consulted before prescribing this drug

Reference:

1. Drug and Therapeutics Bulletin (2004); 42 (7): 49-52.
2. Selective phosphodiesterase type 5 inhibition using tadalafil for the treatment of erectile dysfunction. Expert Opin Investig Drugs. 2002 Nov;11(11):1605-13.