Up until now, hypertension remains a major challenge in the world. Hypertension is a condition that is often found in the primary health care level. In addition, control of hypertension has not been adequate even though effective drugs are now widely available. Hypertension or high blood pressure is an increase in systolic blood pressure over 140 mmHg and diastolic blood pressure over 90 mmHg on two occasions with an interval of five minutes with rest. Hypertension is a silent killer with varied symptoms throughout different individuals.
Hypertension is a disease with a variety of medical conditions. In most patients, the etiology pathophysiology are unknown (essential or primary hypertension). Primary hypertension is not curable but can be controlled and managed. On the other hand, secondary hypertension is caused by special condition.
Primary hypertension (essential hypertension)
More than 90% of patients with hypertension have primary hypertension, also known as essential hypertension. There is no single theory that states the pathogenesis of primary hypertension, however, several mechanism that may contribute to the occurrence has been identified. Due to the hereditary nature of hypertension, it is suggested that genetic also plays an important role in the pathogenesis of primary hypertension.
Less than 10% of patients with hypertension have the condition due to comorbid disease or intake of certain drugs that can increase blood pressure. Secondary hypertension causes can be identified, for example: renal vascular disorders, thyroid gland disorders (hyperthyroidism), or adrenal gland disease (hyperaldosteronism). In about 5-10% of patients with hypertension, the cause is kidney disease. In about 1-2%, the cause is hormonal abnormalities or use of certain medications (e.g., birth control pills).
Factors that Causes Hypertension
There are several factors that triggers high blood pressure. These factors include:
- Lack of exercise
Symptoms of Hypertension
Hypertension has no particular symptoms; however, some symptoms that occur simultaneously can be associated with high blood pressure. These symptoms are:
- Nose bleed
- Facial redness and fatigue
- Throwing up
Primary hypertension cannot be cured, but treatment can be given to prevent complications. There are several classes of drugs that are generally used for the treatment of hypertension. These are:
1. Diuretic Drugs
Diuretics increased excretion of sodium, chloride, and water, thereby reducing the volume of plasma and extracellular fluid. In addition, it helps reduces stiffness of blood vessel wall and increases resilience (vascular compliance).
Diuretic drugs that are often used to lower blood pressure includes:
- Loop diuretics: Ethacrynic acid, furosemide, bumetanide.
- Thiazides: Chlorothiazide, hydrochlorothiazide, hydroflumethiazide, bendroflumethiazide, polythiazide, benzthiazide, cyclothiazide, methyclothiazide, chlorthalidone, , and indapamide.
- Potassium-sparing diuretics: Aldosterone, triamterene, and amiloride.
- Beta-blockers (adrenergic system inhibitors):
Propranolol, metaprolol, and atenolol.
2. ACE-inhibitors (Angiotensin Converting Enzyme Inhibitors)
Drugs known as ACE-inhibitors are useful to prevent blood vessels from constricting by preventing and stopping the formation of angiotensin II. Angiotensin II is a chemical compound that causes constriction of blood vessels. Example of ACE-inhibitors are captopril, enalapril, and lisinopril.
3. Calcium Antagonists
This drug has a fast peak levels, but it can cause adverse side effects in the form of spark myocardial ischemia (lack of oxygen to the heart muscle). This causes cardiac or cerebral ischemia due to a sudden decrease in the arteries. Contraction of the arteries decreases vascular constriction. Calcium antagonist drug class is divided into three, namely:
- Phenylalkylamine: Verapamiland galopamil
- Benzothiazepines: Diltiazem
- Dihydropyridines: nifedipine, amlodipine, and nicardipine