Drugs 2008; 68 (2): 231-250 REVIEW ARTICLE 0012-6667/08/0002-0231/$53.45/0 © 2008 Adis Data Information BV. All rights reserved. Looking to the Future for Erectile Dysfunction Therapies Konstantinos Hatzimouratidis and Dimitrios G. Hatzichristou Center for Sexual and Reproductive Health, Aristotle University of Thessaloniki, Thessaloniki, Greece Contents Abstract .................................................................................... 231 1. What is the Current Status of Erectile Dysfunction (ED) Treatment? ............................ 232 1.1 Phosphodiesterase Type 5 Inhibitors .................................................... 232 1.2 Local Therapies ...................................................................... 233 1.3 Mechanical Devices ................................................................. 234 2. Does the Ideal Treatment for ED Exist? ..................................................... 234 3. Future ED Treatments ..................................................................... 236 3.1 Bremelanotide ...................................................................... 236 3.2 Avanafil ............................................................................ 238 3.3 Udenafil ............................................................................ 239 3.4 SLx-2101 ............................................................................ 240 3.5 Mirodenafil .......................................................................... 241 3.6 Topical Administration of Alprostadil ................................................... 241 3.7 Intracavernosal Injection of a Combination of Aviptadil and Phentolamine ................ 242 3.8 What Do These New Treatments Offer to the ED Patient? ................................ 242 4. Other Future Treatment Options ........................................................... 243 4.1 Dopamine Receptor Agonists ......................................................... 243 4.2 Glutamate Receptor Agonists ......................................................... 244 4.3 Serotonin Receptor Agonists .......................................................... 244 4.4 Guanylate Cyclase Activators ........................................................ 244 4.5 Rho-Kinase Inhibitors ................................................................. 245 4.6 Hexarelin Analogues ................................................................. 245 4.7 Oxytocin ............................................................................ 245 4.8 Gene Therapy ....................................................................... 245 4.9 Tissue Engineering .................................................................... 246 5. Conclusions ............................................................................. 246 The treatment of erectile dysfunction (ED) has been revolutionized during the Abstract last 2 decades with several treatment options now available. Most of these treatments are associated with high efficacy rates and favourable safety profiles. A MEDLINE search was undertaken to evaluate all currently available data on treatment modalities for ED. Phosphodiesterase type 5 (PDE5) inhibitors (sildenafil, tadalafil, vardenafil) are currently the first-choice treatment option for ED by most physicians and patients. In addition, several new PDE5 inhibitors are candidates to enter the market in forthcoming years (avanafil, udenafil, SLx-2101, mirodenafil [SK3530]). However, obvious pharmacokinetic differences that result in a faster time-to-onset, longer half-life time and better safety profile are required for these drugs to be considered a truly better option for patients. Other molecules in development include selective dopamine, glutamate, serotonin and melanocor-