Blood pressure (Hypertension)
Blood pressure is the force of your blood pushing against the walls of your arteries as your heart pumps it through your body. It’s measured as two numbers, written as a fraction (e.g., 120/80), where the top number (systolic) is the pressure when your heart beats, and the bottom number (diastolic) is the pressure when your heart rests between beats. Consistent high blood pressure (hypertension) can damage organs and increase the risk of heart attack, stroke, and kidney disease, highlighting the importance of monitoring and managing it.
- The higher number, which measures pressure when your heart contracts (beats).
- Normal blood pressure: is crucial for supplying vital organs with adequate blood flow.
- High blood pressure (hypertension): forces the heart to work harder, which can:
1. Damage and thicken artery walls.
2. Increase the risk of serious conditions like heart attack, stroke, heart failure, and kidney disease.
- Low blood pressure (hypotension): is less common but can indicate a lack of blood flow to vital organs, leading to dizziness, confusion, or other serious problems.
Treatments of blood pressure (antihypertensives)
An antihypertensive is a medication that lowers high blood pressure (hypertension), preventing serious health issues like stroke, heart failure, and kidney disease. These drugs work in various ways, such as dilating blood vessels, removing salt and water from the body, or blocking hormones that raise blood pressure. Common classes include diuretics, ACE inhibitors, and beta-blockers, with treatment often requiring a combination of medications.
1. Diuretics -
Diuretics, or “water pills,” are substances that increase urine production, helping the body expel excess sodium (salt) and water. Their primary functions include lowering blood pressure by reducing blood volume and fluid retention (edema), and they are used to treat conditions like high blood pressure (hypertension) and heart failure. Diuretics work by acting on the kidneys to inhibit the reabsorption of electrolytes like sodium, which in turn causes more water to be excreted from the body.
Examples –
Thiazide
a.Hydrochlorthiazide
b.chlorthalidone
c.indapamide
High ceiling
a. Furosemide
Aldosterone antagonist
a. spironolactone
b. Eplerenone
2. Renin-angiotensin system inhibitors -
Renin-angiotensin system (RAS) inhibitors are a class of drugs that block the effects of the renin-angiotensin-aldosterone system (RAAS), a hormonal system that regulates blood pressure and fluid balance. Their primary functions are to lower blood pressure, reduce the workload on the heart in conditions like heart failure, and slow the progression of chronic kidney disease by decreasing harmful effects like protein buildup in the kidneys. Key types include ACE inhibitors and Angiotensin Receptor Blockers (ARBs), which reduce blood pressure and prevent organ damage.
Examples –
ACE inhibitors
a. Captropil
b. Enalapril
c. Lisinopril
d. Perindopril
e. Ramipril
Angiotensin receptor blockers
a.Losartan
b. Candesartan
c. Valsartan
d. Telmisartan
e. Olmesartan
Direct renin inhibitors
a. Aliskiren
3. Sympathetic inhibitors -
Sympathetic inhibitors, also known as sympatholytics, are drugs that reduce sympathetic nervous system activity to lower blood pressure. They function by decreasing sympathetic outflow from the brain or blocking its action on the heart and blood vessels, resulting in reduced heart rate, cardiac contractility, and vasoconstriction. Common examples include central acting agents like clonidine, which stimulate α2-adrenergic receptors in the brainstem, and peripheral alpha-blockers such as prazosin.
Examples –
Beta adrenergic blockers
a. Propranolol
b. Metaprolol
c. Atenolol
Alpha + beta adrenergic blockers
a. Labetalol
b. Carvedilol
Alpha adrenergic blockers
a. Prazosine
b. Terazosine
c. Doxazosine
d. Phentolamine
Central sympatholytics
a. Clonidine
b. Methyldopa
4. Calcium channel blockers -
Calcium channel blockers (CCBs) lower blood pressure by preventing calcium from entering the muscle cells of the heart and blood vessels, which relaxes and widens arteries, reducing the strain on the heart. In managing hypertension, CCBs decrease blood pressure by reducing total peripheral resistance and, in some cases, cardiac output. They are a widely used and effective class of drugs for treating high blood pressure, and can also be used for other heart conditions like angina and certain arrhythmias.
Examples –
Phenylalkylamine
a. Verapamil
Benzothiazepine
a. Deltiazem
Dihydropyridines
a. Nifedipine
b. Felodipine
c. Amlodipine
d. Cilnidipine
e. Lasidipine
5. Vasodilators -
These medicines treat a variety of conditions, including high blood pressure. Vasodilators are medicines that help open blood vessels. The medicines affect the muscles in the walls of the arteries and veins. They prevent the muscles from tightening and the walls from narrowing.
Examples –
Artioler dilator
a. Hydralazine
b. Minoxidil
Arterioler + Venodialator
a. Nitroprusside sodium