26 UROLOGY, URO-ONCOLOGY AND SEXOLOGY UPDATE Phosphodiesterase type 5 inhibitors (PDE5i's) are the most popular choice as rst line treatment for erectile dysfunction (ED), however about 30-35% of patients will report treatment failure and may be classied as PDE5i non-responders. Given that the next treatment option if patients do not respond to PDE5i's is intracavernousal injections, which is a less popular treatment option for many patients and which carries a risk of priapism, clinicians should exhaust all factors which may result in incorrectly classifying a patient as a PDE5i non-responder. One study that focused on sildenal nonresponders has shown that reasons for not responding may include factors such as: • taking the medication after a heavy meal • a lack of sexual stimulation • insufcient attempts before reporting nonresponse • Inadequate dosing resulting in a failure to achieve sufcient blood levels of the drug An insufcient dose of the selected PDE5i, together with insufcient attempts at sexual activity appears to be two of the most common reasons for patients not responding to PDE5i's. This was well illustrated in a study by CP Steide et al in 2007, published in the International Journal of Impotence Research, in which 50 mg of sildenal on demand, achieved 1.4 sexual intercourse attempts per week, with a success rate of 82%. When the sildenal dose was increased to 100 mg, the number of sexual intercourses attempts per week increased to 1.7, with a 91% success rate, demonstrating that increasing the dose of sildenal improves both the number of sexual intercourse attempts and the sexual success rate. Research shows that this is also the case with vardenal and tadalal. One possible strategy to avoid the psychological impact of treatment failure with early treatment, is to start at the highest label approved dose, and then to titrate down to a lower dose once a successful response has been achieved. This will reduce the number of patients who would otherwise have presented as PDE5i non-responders because of inadequate dosing. Reference: Cai Z, Song X, Zhang J, et al. Practical Approaches to Treat ED in PDE5i Non-responders. Aging and Disease. Volume 11, Number 5; 12021218, October 2020 Are we underdosing patients with erectile dysfunction with PDE5 inhibitors?
RkJQdWJsaXNoZXIy NTIyOTQ=