Most of the α antagonists allow vasodilation and, thus, decrease blood pressure.

The side effects of the α-blockers are directly related to their α-blocking activity.

TAMSULOSIN and silodosin are specific antagonists of the α1A receptor and are used in the symptomatic treatment of benign prostatic hypertrophy.

All of the α-blockers are reversible inhibitors of the α receptor, except phenoxybenzamine, which is irreversible.

The “-azosins,” such as PRAZOSIN, are used in the treatment of hypertension.

The β-blockers have widespread use in the management of cardiac arrhythmias, angina, and hypertension.

β-Blockers should be used with caution in diabetics.

β1 Selective antagonists are often referred to as cardioselective.

The adverse effects of these drugs are, for the most part, directly related to their β-blocking abilities.

Some β-blockers are said to have intrinsic sympathomimetic activity. This means they have partial agonist activity, even though they are classified as β-blockers.

Labetalol has both α- and β-blocking activity.

The thiazide diuretics inhibit sodium and chloride reabsorption in the thick ascending loop of Henle and early distal tubule. This loss of ions increases urine volume.

The thiazide diuretics are the drugs of choice in the treatment of primary hypertension.

The thiazide diuretics can cause hypokalemia.

The loop diuretics inhibit chloride reabsorption in the thick ascending loop of Henle.

The loop diuretics are commonly used to reduce pulmonary edema in patients with congestive heart failure.

The major side effect of the loop diuretics is hypokalemia.

ACE inhibitors block the synthesis of angiotensin II.

The ARBs interfere with the binding of angiotensin II with its receptor.

Spironolactone and eplerenone are antagonists of aldosterone at the mineralocorticoid receptor and can be used to treat hypertension.

Calcium channel blockers inhibit the entry of calcium into cells. They cause a decrease in afterload.