In summary, AT1 receptor antagonists are designed compounds that elicit greater potencies and clinical potencies as initially suggested, and this may occur independent of their actions at the AT1 receptor. To prove potential independent potencies of active metabolites, further experimental and randomized clinical trials are needed to evaluate the importance of these metabolites. Significant progress was made in the determination of angiotensin II receptor antagonists in human plasma and feces, which will ease the entry into further studies.88-90 The rapid progress in GPCR modeling after disclosure of the rhodopsin structure91 provides detailed insight into the binding mode of Ang II. These refined homology models (Figure 11 and Wilkes et al.)12 will fuel the design of future members of the sartan drug family.