Nature Reviews Drug Discovery 7, 112 (February 2008) | doi:10.1038/nrd2516

This article stated that Caduet is covered by three US patents US 4,681,893 (which covers atorvastatin calcium); 5,273,995 (which covers amlodipine besylate); and 6,455,574 (which covers the product). In fact, both the '893 and the '995 patents relate to atorvastatin calcium.