Guidelines for Hypertension Medication Use in Special Populations: Elderly and Complication Management

What precautions should be taken when treating hypertension in the elderly? Besides choosing appropriate medications, the following should be noted when treating hypertension in the elderly:

① Many elderly individuals have renal artery sclerosis and varying degrees of renal function decline, resulting in relatively slower drug metabolism. Therefore, the dosage should be small, starting with a low dose, generally controlled at 1/2 to 2/3 of the normal dose, to avoid drug accumulation or adverse reactions;

② Elderly patients with hypertension often have systemic arteriosclerosis. Sudden drops and large fluctuations in blood pressure should be avoided to prevent insufficient blood supply to vital organs such as the heart, brain, and kidneys;

③ Elderly individuals have poor blood pressure regulation; sympathetic ganglion blockers should be avoided as much as possible to prevent orthostatic hypotension;

④ Strong diuretics, such as furosemide (Lasix), should be avoided to prevent water and electrolyte imbalances;

⑤ Elderly individuals have poor myocardial contractility and sinoatrial node function; antihypertensive drugs that inhibit myocardial contraction and affect the cardiac conduction system should be avoided;

⑥ Some elderly individuals suffer from depression; reserpine (contained in Reserpine tablets) should be avoided.

How should medication be used for isolated systolic hypertension in the elderly?

Isolated systolic hypertension is defined as a systolic blood pressure ≥140 mmHg and a diastolic blood pressure <90 mmHg. The prevalence of hypertension gradually increases with age. 40%–50% of people over 60 years of age have hypertension, of which about half have isolated systolic hypertension. Isolated systolic hypertension increases the afterload of the left ventricle, leading to right ventricular hypertrophy, increasing myocardial oxygen consumption, altering coronary blood flow perfusion and distribution, and reducing coronary reserve in emergency situations. Simultaneously, increased pulse pressure can accelerate damage to the vascular endothelial system and arterial walls, inducing cardiovascular and cerebrovascular events. These patients should be treated with antihypertensive therapy primarily using long-acting dihydropyridine calcium channel blockers and thiazide diuretics to reduce the incidence of cardiovascular and cerebrovascular diseases, with a particularly significant reduction in the incidence of stroke. For patients with isolated systolic hypertension, treatment should be cautious, aiming to lower systolic blood pressure to 140 mmHg while ensuring diastolic blood pressure does not fall below 70 mmHg. Evidence suggests that further lowering already low diastolic blood pressure is detrimental to blood pressure control, and patients with diastolic blood pressure <65 mmHg have an increased risk of stroke. For the drug treatment of isolated systolic hypertension, five effective combination therapy regimens are recommended:

① Dihydropyridine calcium channel blockers and thiazide diuretics;

② Dihydropyridine calcium channel blockers and ACEIs or ARBs;

③ Diuretics and ACEIs or ARBs;

④ Diuretics and beta-blockers;

⑤ Alpha-blockers and beta-blockers.

How should antihypertensive drugs be chosen for pregnant women with hypertension? Most patients with pre-existing hypertension experience a mild to moderate increase in blood pressure during pregnancy (140-179/90-109 mmHg). Because pregnant women are considered low-risk for cardiovascular complications, and both maternal and neonatal prognoses are generally good, non-pharmacological treatment is usually sufficient. Severe hypertension during pregnancy requires medication, but it is crucial to consider not only the mother's risk but also the effects of the medication on the fetus. For mild cases, methyldopa, calcium channel blockers, and beta-blockers are commonly used.

If blood pressure exceeds 180/110 mmHg, hospitalization is necessary. Pregnant women should pay special attention to the following two points when choosing antihypertensive drugs:

① ACEIs or ARBs are contraindicated as they can cause fetal malformations;

② Diuretics should be used with caution, especially in patients with preeclampsia, as they may reduce the pregnant woman's effective blood volume.

How should antihypertensive drugs be chosen for patients with hypertension and diabetes?

The first-line drugs should be angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs).

These two types of drugs have the following effects on diabetic patients:

① While lowering blood pressure, they can also improve the sensitivity of muscles and fat to insulin;
② They have no effect on blood glucose and lipid metabolism, and sometimes can even improve glucose and lipid metabolism;
③ They can inhibit the proliferation of arterial smooth muscle, prevent the formation of atherosclerosis, reduce or reverse left ventricular hypertrophy, and improve myocardial function;

④ They can significantly reduce microalbuminuria in patients with early-stage diabetic nephropathy, thus protecting the kidneys. Commonly used ACEIs (also known as pril classes) include captopril (Capoten), enalapril (Enalapril), quinapril (Evonik), benazepril (Lodin), fosinopril (Monopril), and cilazapril (Cialis). Commonly used ARBs (also known as angiotensin receptor blockers) include losartan (Cozaar) and valsartan (Diovan). Calcium channel blockers (CCBs) are also used. These drugs have good antihypertensive effects, have no effect on glucose metabolism, and are widely used in the treatment of hypertension, coronary heart disease, and cerebrovascular disease. It can also be used as a good drug for antihypertensive treatment in patients with both diabetes and hypertension. Hypertension and the development of diabetic nephropathy are closely related. Elevated arterial blood pressure can increase the pressure within the glomeruli, leading to increased protein content in the urine, thus further worsening the condition of patients with diabetic nephropathy. Calcium channel blockers not only lower blood pressure but also significantly reduce protein content in the urine of diabetic patients, altering their renal function. These drugs are also known as dihydropyridines, and commonly used ones include nifedipine controlled-release tablets (Adalat), amlodipine (Lovastatin), and felodipine (Plendil).

Why is antihypertensive treatment necessary for diabetes? The common underlying cause of hypertension and diabetes is insulin resistance. Therefore, in patients with both diabetes and hypertension, it is essential to control both blood pressure and blood sugar. Controlling blood pressure is no less important than controlling blood sugar, especially for patients with existing diabetic nephropathy. Blood pressure control is not only crucial for protecting the kidneys but also a means of preventing diabetic nephropathy. Blood sugar and blood pressure treatment can be carried out simultaneously in patients with both hypertension and diabetes. However, if a patient's blood sugar is well-controlled but their blood pressure frequently exceeds 160/108 mmHg, or if they are simultaneously diagnosed with kidney or heart disease, lowering blood pressure becomes more urgent than lowering blood sugar. Furthermore, blood pressure must be controlled to the target level: blood pressure should be <130/80 mmHg; for hypertensive patients with impaired kidney function and proteinuria <1g/day, blood pressure should be <130/80 mmHg; for hypertensive patients with impaired kidney function and proteinuria >1g/day, blood pressure should be <125/75 mmHg. This is because these patients are at greater risk.

Which antihypertensive drugs should diabetic patients use with caution? Hypertension is one of the main complications of diabetes. When treating hypertension in diabetic patients, the following two types of drugs should be carefully selected: ① Diuretics: Most diabetic patients with hypertension have fluid retention; therefore, administering small amounts of diuretic antihypertensive drugs can significantly improve hypertension. However, diuretics can cause hypoglycemia in diabetic patients, reduce insulin secretion and sensitivity, thus worsening glucose tolerance. They may also affect uric acid and lipid metabolism. Therefore, diuretics should not be the first-line treatment and should only be used in short periods and at low doses. Studies have shown that 20% of patients using hydrochlorothiazide diuretics long-term may develop impaired glucose tolerance, with elevated fasting and postprandial blood glucose levels.

② Beta-blockers: These drugs inhibit insulin secretion and reduce the body's sensitivity to insulin, thus decreasing glucose tolerance. Simultaneously, because hepatic glycogenolysis is inhibited, they can exacerbate hypoglycemic reactions caused by hypoglycemic drugs in diabetic patients. Furthermore, because beta-blockers slow the heart rate due to their blocking effect on beta receptors, they can mask early hypoglycemic states (such as palpitations). Therefore, beta-blockers are often not chosen for patients with hypertension and diabetes. However, numerous clinical studies have now confirmed that beta-blockers can significantly improve the prognosis of patients with coronary heart disease and heart failure. The UK Prospective Diabetes Study also confirmed that the benefits of beta-blockers for diabetic patients outweigh the side effects. However, blood glucose fluctuations must be monitored closely during treatment.

Why are ACE inhibitors the first-line treatment for patients with hypertension and diabetes?

The first-line antihypertensive drug for patients with hypertension and diabetes should be angiotensin-converting enzyme inhibitors (ACEIs). This is because these drugs not only lower blood pressure but also improve the sensitivity of muscles and fat to insulin without affecting glucose and lipid metabolism; they inhibit arterial smooth muscle proliferation, delay or prevent atherosclerosis, reduce or reverse left ventricular hypertrophy, and improve myocardial function; they also protect kidney function, and have a significant effect on reducing microalbuminemia in patients with early-stage diabetic nephropathy.