The drugs used in the treatment of hypertension are called antihypertensive. Thanks to the wide range of antihypertensive agents available, hypertension can be controlled in almost all subjects, but the treatment must be tailored to each individual. (See also arterial hypertension.) Treatment is most effective when there is good dialogue between patient and doctor and good collaboration on the therapeutic program.
Adrenergic blockers
Adrenolytics include alpha-blockers, beta-blockers, alpha-beta-blockers, and peripheral adrenolytics. These drugs block the effects of the sympathetic system, the part of the autonomic nervous system that can quickly respond to stress with the increase in blood pressure.
Beta blockers are the most commonly used adrenergic blockers. They are particularly useful in Caucasians, in young people and in people who have suffered a heart attack. They are also useful for people with tachycardia, angina pectoris (chest pain due to inadequate blood flow to the heart muscle) or migraine headaches. The risk of side effects is higher among the elderly.
Angiotensin converting enzyme inhibitors
Angiotensin converting enzyme (ACE) inhibitors reduce blood pressure in part by dilating the arterioles. This action takes place by preventing the formation of angiotensin II, a chemical produced by the body that causes arterioles to constrict. Specifically, these inhibitors block the action of the angiotensin converting enzyme, which converts angiotensin I to angiotensin II (see figure Blood pressure regulation). These drugs are particularly useful in cases of coronary artery disease, heart failure, in Caucasians, in young people, in people who have a loss of protein in the urine due to chronic kidney disease or diabetic nephropathy, and in men who develop sexual dysfunction as a result of a other antihypertensive.
Angiotensin II receptor blockers
Angiotensin II receptor blockers (ARBs) reduce blood pressure through a mechanism similar to that used by angiotensin converting enzyme inhibitors: they directly block the action of angiotensin II, which often induces blood pressure. narrowing of the arterioles. Since the mechanism is more specific, angiotensin blockers cause fewer side effects.
Calcium channel blockers
Calcium channel blockers cause arterioles to dilate via a completely different mechanism. They are particularly useful in black people and the elderly. Calcium channel blockers are also useful in people with angina pectoris, certain types of tachycardia or migraine headaches. Calcium channel blockers can have a short or long duration of action. Short-acting calcium channel blockers are not used to treat hypertension. Some reports suggest that the use of short-acting calcium channel blockers may cause an increased risk of death from heart attack, while there is no evidence of this complication for long-acting calcium channel blockers.
Summary
Gli alfa-agonisti ad azione centrale riducono la pressione arteriosa attraverso un meccanismo in qualche modo simile a quello dei bloccanti adrenergici. Stimolando alcuni recettori nel tronco cerebrale, questi agonisti inibiscono gli effetti della sezione simpatica del sistema nervoso. Attualmente, tali farmaci sono raramente utilizzati.