Numerous clinical and laboratory studies have shown that selective α1-adrenergic receptor blocking agents lower blood pressure by reducing increased total peripheral vascular resistance. Terazosin, a new, long-acting selective α1-adrenergic antagonist, has been shown to be effective in the treatment of mild to moderate essential hypertension. Its pharmacokinetic and pharmacodynamic characteristics are similar to those of prazosin, except that terazosin has a longer plasma elimination half-life, which allows once-daily administration. Both terazosin monotherapy and terazosin in combination with other antihypertensive agents have been shown to produce sustained mean systolic and diastolic blood pressure reductions in supine and standing positions. Terazosin was generally well tolerated during short-term and long-term clinical trials. There were no clinically significant laboratory abnormalities with long-term oral administration of the drug. Moreover, terazosin did not produce significant changes in supine or standing heart rates, and syncope was very uncommon with terazosin monotherapy. The α1-adrenoreceptor antagonists tend to reduce total and low-density lipoprotein (LDL) cholesterol levels, lower triglyceride levels, and increase high-density lipoprotein (HDL) cholesterol levels. Since elevated levels of total cholesterol, LDL cholesterol, and triglyceride increase a patientʼs risk of coronary heart disease, α1-adrenoreceptor antagonists should be considered as first-line therapy for hypertensive patients with abnormal, elevated baseline lipid values.