Week 3 - Hypertension Treatments Flashcards
What are the main classes of antihypertensive drugs?
- Vasodilators
- Sympathetic inhibitors
- Renin-angiotensin system blockers
- Diuretics
How do vasodilators help lower blood pressure?
They relax blood vessels, reducing resistance and lowering blood pressure.
What are two examples of vasodilators?
- Calcium channel blockers
- Arteriolar dilators
What is the function of sympathetic inhibitors in hypertension treatment?
They reduce nerve signals that cause blood vessels to constrict, lowering blood pressure.
What are the two main types of renin-angiotensin system blockers?
- ACE inhibitors (Angiotensin-converting enzyme inhibitors)
- Angiotensin-receptor antagonists
What are examples of sympathetic inhibitors?
- β-adrenoceptor antagonists (Beta-blockers)
- α-adrenoceptor antagonists (Alpha-blockers)
- Central adrenergic drugs
What is the role of renin-angiotensin system blockers in controlling blood pressure?
They help regulate fluid balance and vessel constriction to lower blood pressure.
What is the function of diuretics in hypertension management?
They remove excess fluid from the body, reducing blood volume and blood pressure.
What are the different types of diuretics?
- Loop diuretics
- Thiazides
- Potassium-sparing diuretics
- Aldosterone-receptor antagonists
What is the mechanism of action of calcium channel blockers?
They block calcium ion entry into myocardial and smooth muscle cells, reducing contraction strength, dilating coronary arteries, and lowering blood pressure.
How do calcium channel blockers affect the myocardium?
They decrease myocardial contraction force by blocking calcium entry, reducing the heart’s oxygen demand.
What effect do calcium channel blockers have on vascular smooth muscle?
- Dilate coronary arteries → improve blood flow.
- Relax peripheral arterioles → reduce vascular resistance and blood pressure.
- Reduce afterload → decrease oxygen demand on the heart.
How do calcium channel blockers affect the SA node and AV junction?
They decrease automaticity in the SA node and slow conduction in the AV node, reducing heart rate (negative chronotropic effect).
What are the main indications for calcium channel blockers?
- Angina
- Hypertension
- Supraventricular tachydysrhythmias (Verapamil)
C- erebral vasospasm after subarachnoid haemorrhage (Nimodipine)
What are three examples of calcium channel blockers?
- Verapamil
- Diltiazem
- Amlodipine.
What is the mechanism of action of arteriolar dilators?
They act as direct smooth muscle relaxants, causing vasodilation in arterioles and lowering blood pressure.
What are three examples of arteriolar dilators?
- Hydralazine
- Minoxidil
- Nifedipine.
What is the mechanism of action of β-adrenoceptor antagonists (beta-blockers)?
They block β1-adrenoceptors, reducing heart rate, myocardial contractility, cardiac output, and renin secretion, leading to lower blood pressure and oxygen demand.
What are the cardiovascular effects of beta-blockers?
- Reduce heart rate and myocardial contractility → lower myocardial oxygen demand.
- Slow conduction in the atria and AV node → antidysrhythmic effects.
- Suppress renin secretion → reduce blood pressure.
What are some indications for beta-blockers?
- Angina pectoris
- Hypertension
- Cardiac dysrhythmias
- Myocardial infarction (acute & long-term)
- Heart failure
: What are the two types of beta-blockers and their examples?
- Selective β1-antagonists: Atenolol, Bisoprolol, Metoprolol, Nebivolol.
- Non-selective β1 & β2-antagonists: Oxprenolol, Pindolol.
How do α-adrenoceptor antagonists work?
They selectively block α1-adrenoceptors, reducing vasoconstriction and decreasing peripheral vascular resistance.
Give an example of an α-adrenoceptor antagonist.
Prazosin
What is the mechanism of action of centrally acting adrenergic inhibitors?
They stimulate α2-receptors in the brain, decreasing sympathetic outflow, which lowers heart rate, cardiac output, and blood pressure.
