PDE5A and Alzheimer disease: Recent contributionsin the literature demonstrate the growing interest toward the identificationof small molecules concurrently acting on PDE5 and on a secondarytarget involved in AD.142 This strategywould also aid the development of more targeted and personalized therapeuticapproaches.143 In particular, the combinationof the inhibitory effects on PDE5 and AChE is particularly attractive.In this context, a direct comparison between three of the most widelystudied and promising PDE5 inhibitors discussed previously is providedbelow.