In the early 1980s, two new classes of antihypertensive agents, the calcium antagonists and ACE inhibitors, were developed and licensed for use in chronic antihypertensive therapy. These agents cost more than older agents such as diuretics and beta-blockers, and evidence was limited that might justify their use despite the increased cost. The 1988 Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure recommended beta-blockers, calcium antagonists, ACE-inhibitors, and diuretics as equally acceptable first-line therapy. All four classes of drugs have been found to control diastolic blood pressure as single agents in 50 percent or more of patients with mild hypertension.