A therapeutic taxonomy of treatments for erectile dysfunction: an evolutionary imperative

Aim of the study: A functional classification of treatments for erectile dysfunction is important but none exists at present. Advances in the understanding of the mechanisms of drug action and of the mechanisms of penile erection suggest that there is now a rational basis for a therapeutic classification, with the expectation that a logical diagnostic classification will follow. Methods: The currently available treatments for erectile function and the known relevant basic science were reviewed and assessed. From this, and analysis of classification systems in other fields, a classification was proposed and evaluated with respect to existing treatments. Results: The treatments for erectile dysfunction were classified into five major classes by their mode of action: (I) Central Initiators, (II) Peripheral Initiators, (III) Central Conditioners, (IV) Peripheral Conditioners and (V) Other. Drugs in these classes are further subdivided by the routes of administration and the mechanisms of specificity. Conclusions: It is possible to analyze all known treatments using this classification. The principles of this scheme should be sufficiently clear as to enable knowledgeable specialists to arrive at similar conclusions about a drug. The classification proposed is general enough such that most new drugs should fall within a class. However, it should be modified if necessary, if new therapeutic agents can not be appropriately classified. It is our conclusion that with such endeavours the speciality itself and national regulatory bodies will find it easier to define and control how to apply new drugs, how to evaluate new drugs, and how to establish reasonable equivalences among agents and in whom these drugs and devices should be used.