Worldwide, many adults have high blood pressure. Admittedly, the risk of developing a hypertension condition increases with age. At a young age, elevated blood pressure may be caused by diets high in salt (sodium chloride), obesity, or inadequate physical activity. However, these factors are less important than they are at older ages. Research indicates that about 90 percent of cases are essential hypertension (meaning that no other disease is involved). Lifestyle changes are first-line treatments, including dietary reductions in salt intake, physical exercise, and weight loss. Various medications are available if lifestyle changes are insufficient for blood pressure control. Some common examples include:
Diuretics typically work by increasing the excretion of water and sodium through urination, which reduces blood volume and thus lowers blood pressure. These drugs might act within hours but usually take several days for full effect. Almost all diuretics can cause low plasma potassium (hypokalemia) at the usual doses; thiazide-type diuretics also deplete serum magnesium levels. However, this is not clinically significant unless there is concomitant use of another medication causing these effects; in such cases, supplementation with oral potassium chloride or spironolactone could be considered since they block the adverse effects of these drugs without interfering with their antihypertensive effect.
Diuretics are given orally or intravenously in most cases except for an acute hypertensive emergency. They are injected rapidly, often intramuscularly, allowing them to reach their site of action more quickly. Some examples of diuretics include hydrochlorothiazide, chlorthalidone, furosemide (Lasix), spironolactone (Aldactone), and bumetanide.
ACE inhibitors inhibit the activity of an angiotensin-converting enzyme which converts angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor, so blocking its formation results in vasodilation and blood pressure reduction. ACE inhibitors also directly reduce arterial stiffness and may be protective against diabetic nephropathy.
ACE regulates many other peptides in the body, which makes these drugs very difficult to use with other medications, especially some antibiotics such as aminoglycosides at high doses. Side effects include dry cough due to bradykinin accumulation which is usually mild but can be more severe if there's bilateral renal artery stenosis or concomitant treatment with NSAIDs. Examples include captopril, enalapril, lisinopril, quinapril.
Angiotensin II receptor blockers
They act by blocking the receptors of angiotensin II, resulting in vasodilation without affecting bradykinin. Therefore, they have similar effects as ACE inhibitors but no cough and no hyperkalemia. Instead, there may be a decreased incidence of dry cough and hypotension. They can treat high blood pressure or heart failure due to systolic dysfunction and kidney disease in those patients with reduced systolic function. When these drugs are given with diuretics, they have additive effects on decreasing death from cardiovascular causes, stroke, renal disease progression, and myocardial infarction compared to either drug alone. Some examples include losartan (Cozaar), valsartan (Diovan), irbesartenlin (Avapro) and olmesartaen (Benicar).
Vasopressin receptor blockers
Vasopressin receptor blockers act by blocking receptors on vascular smooth muscle cells of vasopressin, thus resulting in vasodilation and reduced blood pressure. This effect may be weaker than vasodilators, but they also have less severe adverse effects, such as reflex tachycardia (which can be used to treat some cases of atrial fibrillation). Some examples include conivaptan (Vaprisol), tolvaptan (Samsca), and lixivaptan (Adlyxin, VLY-686).