US Pharm. 2009;34(11):54-56. 

Despite the generic erosion of many hypertension drug products expected over the next decade, it is estimated that the overall hypertension drug market will experience only a modest decline. According to Decision Resources, a research and advisory firm for pharmaceutical and health care issues, the market will decrease 1.4% annually through 2013, and thereafter the annual decline will slow to 1% through 2018 in the United States, France, Germany, Italy, Spain, the United Kingdom, and Japan.

According to a company report, a major contributor to the market decline will be an increase in the generic availability of antihypertensive agents. For example, by 2018, Novartis's Diovan alone will lose more than $1 billion in sales beginning next year when the drug goes off patent. Other hypertension drug classes will suffer as well, including angiotensin-converting enzyme inhibitors (ACE inhibitors), angiotensin II receptor antagonists, calcium channel blockers, and diuretics.