This brief explores in detail the impact of generic ACE inhibitors on the AIIRB market, a theme raised in recent Datamonitor reports covering antihypertensive drugs. It is particularly topical, given the recent FDA approval of Sankyo Pharma/Forest Laboratories' new angiotensin II receptor blocker, Benicar (olmesartan) for marketing in the US. The Brief draws together and builds on Treatment Algorithm survey findings in heart failure and hypertension for 7 countries, with epidemiology data, literature search material and a case study based on UK Department of Health prescription audit data for England. The Brief provides: * detailed analysis of the estimated proportion of hypertensive and heart failure patients that are ACE intolerant in the seven major pharmaceutical markets (US, Japan, Germany, France, Italy, Spain, UK) * clinical trial data investigating ACE inhibitor intolerance * a breakdown of the causes of ACE inhibitor intolerance * assessment of alternative therapies for ACE intolerant patients * summary of ACE inhibitor and AIIRB prescription trends in England from 1998 to 2001, and an analysis of the impact of generic enalapril within this market.