Tadalafil and modifications in peak systolic velocity (Doppler spectrum dynamic analysis) in the cavernosal arteries of patients with type 2 diabetes after continuous tadalafil treatment.

Aim: In this study peak systolic velocity (PSV) was measured by penile duplex Doppler spectrum dynamic analysis in diabetic patients with erectile dysfunction (ED) administered continuous treatment with tadalafil for 3 months in a weekly regimen (Monday-Wednesday-Friday). Responses to the Structured Interview on Erectile Dysfunction (SIEDY) questionnaire and hormonal blood levels (LH, testosterone, prolactin) were studied before and after treatment.
Methods: The study sample was 20 diabetic patients (mean age 60 years; range 55-65) with organic vascular arterial ED at enrollment into the study. All patients were eligible for receiving tadalafil. Patients were randomly assigned to 2 different treatment groups according to a computer-generated list. The first random set of numbers was assigned to group A, the second to group B. Group A (n=10) received tadalafil 20 mg per os on demand for 3 months (Cialis, Lilly ICOS; London, UK). Group B (n=10) received tadalafil 20 mg per os on weekly fixed days (Monday-Wednesday-Friday) for 3 months. All patients underwent duplex penile sonographic dynamic evaluation after intracavernosal injection of alprostadil 20 microg (Caverject, Pharmacia SpA; Milan, Italy); SIEDY questionnaire responses and changes in blood hormonal levels (LH, testosterone, prolactin) before and after treatment were compared.
Results: Increased PSV at 10 min and 20 min after alprostadil administration was found in 30% of Group A patients and in 60% of Group B patients. In 40% of Group B patients, the increase in PSV was so significant as to justify reclassification to a less severe diagnostic category (Benson classification) in vascular profile. No changes in hormonal levels after treatment were found in either group. Analysis of the questionnaires showed a more marked reduction in the global total scores in Group B, with a greater frequency and a clearer improvement in global scores.
Conclusions: This study on a group of 20 patients with organic vascular arterial ED disclosed at least 2 basic aspects: 1) a higher percentage of Group B patients (fixed-day treatment regimen) showed a greater improvement in PSV than the controls; 40% of these patients were reclassified according to the Benson classification; 2) within the context of a clinical study, monitoring and supportive care to increase the frequency and quality of sexual intercourse led to a resumption of and a greater interest in sexual activity. This finding cannot be explained by changes in hormonal levels; instead, there appeared a sort of effect placebo that the continuous therapy, like conventional treatment for other health reasons, had on the patient.