OBJECTIVE To assess whether the longer half‐life of tadalafil is associated with longer lasting or more severe side‐effects than the other phosphodiesterase type 5 inhibitors (PDE‐5Is), as clinical trials have shown that the efficacy and safety of the three available are similar, but tadalafil has a half‐life four times longer than the other two drugs. PATIENTS AND METHODS Treatment‐naive men beginning PDE5‐I therapy were recruited from a specialist clinic. Data on the type and duration of drug‐associated side‐effects were collected prospectively. Levels of bother were assessed with a visual analogue scale (VAS). Differences in type, duration and bother of side‐effect were compared between drugs. RESULTS In all, 409 men provided data; there were no differences between drugs in the proportion of men responding, or the overall prevalence of side‐effects. The mean duration of side‐effects with tadalafil was 14.9 h, compared to 3.9 and 7.7 h for sildenafil and vardenafil. Of men taking tadalafil, 30% had side‐effects lasting >12 h. There were no differences in mean VAS scores between the drugs. Individual side‐effects caused similar levels of bother, except for facial flushing, which was less bothersome. CONCLUSIONS Men taking tadalafil are at risk of prolonged side‐effects, although levels of bother associated with these side‐effects are not significantly greater than those seen with short‐acting PDE5‐Is.

Introduction The United Kingdom is unusual in that a significant proportion of patients with erectile dysfunction (ED) have their treatment fully reimbursed by the National Health Service (NHS). This may have consequences for the choice of treatment and for compliance with treatment. Aims The aim of this study was to evaluate the use and cost implications of phosphodiesterase type 5 inhibitor in an NHS setting. Methods Basic demographics and data on ED management for patients treated from January 2000 to April 2011 were obtained from a prospectively accrued database. We reviewed drug usage and costs as well as switching between drugs. Patients were given the choice of all available therapies and were followed up annually. Main Outcome Measures Switching, compliance, and costs of treating ED under the “severe distress” criteria in the NHS were reviewed for this study. Results Two thousand one hundred fifty-nine patients qualified for reimbursed therapy. Two hundred twenty-six patients were excluded from further analysis owing to missing data. Patients were followed up on an annual basis. The mean patient age was 60.2 years (min 23, max 90), and the mean follow-up was 50.8 months (min 1, max 127). Six hundred ninety-six were started on sildenafil, 990 on tadalafil, 163 on vardenafil, and 84 on intracavernosal alprostadil. Eighteen percent of patients initially started on the scheme and stopped medication unilaterally. Of the patients, 12.3% changed their medication during follow-up. The cost of drugs increased year by year from £257,100 in 2007 to £352,519 in 2011. Conclusions Our real-life observational study shows that in our institution, dropout of therapy is unusual. We hypothesize that this reflects, in part, the reimbursement issue. We also found that switching between drugs was unusual, although there are several possible explanations for that. Although this is a successful system for the patients, the hospital, which bears the costs of medication, is finding this an increasing economic drain.