a report by Konstantinos Hatzimouratidis and Dimitrios G Hatzichristou Lecturer in Urology, and Associate Professor in Urology/Andrology and Founder, Centre for Sexual and Reproductive Health, Aristotle University of Thessaloniki Erectile dysfunction (ED) is a highly prevalent disease that is expected to affect 322 million men by 2025. Risk factors include ageing, cardiovascular disease (CVD), diabetes, hyperlipidaemia, smoking, absence of physical exercise and obesity. ED is associated with depression and has a negative impact on patients’ and partners’ quality of life. Potentially reversible causes include specific endocrinopathies, pelvic or perineal trauma, drugs, lifestyle and psychosocial factors. However, the majority of men with ED will not be treated with cause-specific treatment options. The advent of new oral drugs has revolutionised the treatment of ED. Optimal therapy for patients with ED may be challenging. In order to properly counsel patients with ED, physicians must be fully informed on all treatment options as part of a patient-centred model of care for ED. Oral Pharmacotherapy Sildenafil Sildenafil was the first phosphodiesterase type 5 (PDE5) inhibitor, and it has been available since 1998. It is administered orally on demand in 25mg, 50mg and 100mg doses in the presence of sexual stimulation (maximum dosing once-daily). The recommended starting dose is 50mg. The onset of action can be less than 30 minutes and efficacy may be maintained for up to 12 hours. A heavy fatty meal results in reduced and prolonged absorption. Alcohol does not have an impact on absorption in regular doses. Successful sexual intercourse was demonstrated in 69% of all attempts for the men receiving sildenafil (compared with 22% for placebo; p<0.001) (see Table 1). Mean numbers of successful attempts per month were 5.9 for sildenafil compared with 1.5 for placebo. In a three-year study, 32% of patients discontinued treatment. Only 6.7% of discon- tinuations were treatment-related (5.7% for insufficient response and 1% for adverse events). Most patients received 100mg sildenafil doses (88% at three years). Improvement in the ability to achieve erections was reported by 71% of patients in a clinical practice setting. The efficacy of sildenafil in almost every subgroup of patients (elderly men, patients with ischaemic heart disease, hypertension, chronic renal failure (CRF), spinal cord injury, depression and bilateral nerve-sparing radical prostatectomy) is well established. Lower efficacy rates are expected in diabetic patients (50–60%). Both patients and partners report higher levels of satisfaction (up to 90%) after sildenafil treatment relative to placebo. Sildenafil also improved all aspects of health-related quality of life. Common adverse events are presented in Table 2. They are usually mild and self-limited by continuous use, and the drop-out rate due to adverse events is similar to that of placebo. No increase in myocardial infarction (MI) rates was demonstrated. Concomitant use of sildenafil with nitrates is contraindicated. Sildenafil labelling includes a precaution advising that 50mg or 100mg (not 25mg) of sildenafil should not be taken within a four-hour window of an alpha-blocker. This may not be the case when tamsulosin or alfuzosin is used. Tadalafil Tadalafil is a PDE5 inhibitor with a different pharmacokinetic profile. It is administered orally on demand in 10mg and 20mg doses in the presence of sexual stimulation. The recommended starting dose is 10mg. The earliest time to onset of action leading to successful intercourse can be only 30 minutes; however, as time taken to reach peak plasma concentration (T max ) is two hours, it seems reasonable to instruct patients to take tadalafil approximately two hours before sexual intercourse, with a maximum dosing frequency of once every other day, as its efficacy is maintained at least for 36 hours. Absorption is not affected by food or regular alcohol intake. Efficacy was assessed in 11 randomised double-blind placebo-controlled clinical studies (see Table 1). An Update on Pharmacological Treatment of Erectile Dysfunction 92 Erectile Dysfunction BUSINESS BRIEFING: EUROPEAN ENDOCRINE REVIEW 2006 Konstantinos Hatzimouratidis Dimitrios G Hatzichristou Konstantinos Hatzimouratidis is a lecturer in urology at the Centre for Sexual and Reproductive Health at Aristotle University of Thessaloniki, Greece. He is a fellow of the European Board of Urology (FEBU), Editor-in-Chief of the European Society for Sexual Medicine (ESSM) website and newsletter and member of the Communications Committee of the International Society for Sexual Medicine (ISSM). Dr Hatzimouratidis is a reviewer for European Urology and the Journal of Sexual Medicine. He graduated and completed his training in urology at the Aristotle University Medical School in Thessaloniki. Dimitrios Hatzichristou is Associate Professor of Urology/Andrology and the founder of the Centre for Sexual and Reproductive Health at Aristotle University of Thessaloniki, Greece. Dr Hatzichristou is Chairman (2004 to 2006) of the European Sexual Dysfunction Alliance (ESDA), a faculty member of the European School of Urology (ESU), founding member of the European Society of Andrological Urology (ESAU) and a member of the International Society for Sexual and Impotence Research (ISSIR). DOI:10.17925/EE.2006.00.02.92