Drugs Used in Hypertension Overview

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Questions and Answers

What are the two types of arrhythmias that digoxin specifically targets?

Digoxin targets both ventricular and supraventricular arrhythmias.

In which class of antiarrhythmic drugs does amiodarone belong?

Amiodarone belongs to Class III antiarrhythmic drugs.

How do beta-blockers like propranolol and atenolol influence heart rate?

Beta-blockers decrease heart rate by inhibiting the effects of norepinephrine and epinephrine.

What is the primary action of Class IA antiarrhythmic drugs such as procainamide?

Class IA drugs primarily block fast sodium (Na+) channels. Signup and view all the answers

Which specific drug in the Class IB category is commonly administered intravenously?

Lidocaine is the Class IB drug that is commonly given intravenously. Signup and view all the answers

What is the effect of verapamil on calcium channels?

Verapamil inhibits calcium (Ca²+) channels. Signup and view all the answers

Sotalol is classified under which group of medications?

Sotalol is classified as a Class III antiarrhythmic drug. Signup and view all the answers

What is the mechanism of action of Class IC agents like flecainide and propafenone?

Class IC agents decrease fast Na+ current. Signup and view all the answers

What is the significance of the 'SAN' in the context of arrhythmia management?

The 'SAN' refers to the Sinoatrial Node, which is the natural pacemaker of the heart. Signup and view all the answers

Which stress hormones are associated with increased heart rate, as mentioned in the content?

Norepinephrine and epinephrine are the stress hormones linked to increased heart rate. Signup and view all the answers

What is the significance of lifestyle modifications in managing blood pressure?

Lifestyle modifications like a healthy diet, increased exercise, and smoking cessation significantly reduce blood pressure and cardiovascular risk. Signup and view all the answers

In what scenarios might vasodilators still be used despite the preference for ACE inhibitors and calcium antagonists?

Vasodilators may be used in patients with additional conditions, such as angina, heart failure, or after a myocardial infarction. Signup and view all the answers

How do ACE inhibitors and ARBs function in the treatment of hypertension?

ACE inhibitors decrease the synthesis of angiotensin II, while ARBs block its effects, leading to reduced blood pressure. Signup and view all the answers

What is the prevalence of drug treatment necessity among the UK population regarding hypertension?

Almost a third of the UK population requires drug treatment for hypertension. Signup and view all the answers

Why are centrally acting drugs seldom used in hypertension treatment?

Centrally acting drugs are rarely used due to their significant adverse effects. Signup and view all the answers

What is the treatment strategy for mild-to-moderate hypertension?

Mild-to-moderate hypertension is typically managed with a single drug, though many patients require combinations of two or three. Signup and view all the answers

What challenges exist in properly managing hypertension with medication?

Many patients, if not most, do not have their blood pressure adequately controlled despite treatment. Signup and view all the answers

What role does alcohol and salt intake play in hypertension management?

Moderation of alcohol and salt intake is essential as it helps in reducing blood pressure. Signup and view all the answers

What is the role of pacemaker cells in the sinoatrial node?

Pacemaker cells in the sinoatrial node determine the rhythm of the heart by generating electrical impulses. Signup and view all the answers

How do β-receptors affect cardiac function during stress conditions?

β-receptors increase cardiac activity by enhancing the gNa, which can lead to arrhythmias during stress. Signup and view all the answers

What happens to the effective refractory period when it is increased?

An increased effective refractory period can prevent premature heartbeats and stabilize the cardiac rhythm. Signup and view all the answers

Why might a patient with ventricular arrhythmias be treated with β-blockers?

β-blockers can inhibit the adrenergic stimulation of the heart, helping to control ventricular arrhythmias. Signup and view all the answers

What are the potential consequences of arrhythmias?

Consequences of arrhythmias can range from mild discomfort to severe events like heart failure or sudden death. Signup and view all the answers

How do changes in gK and gNa influence cardiac action potentials?

Decreased gK and increased gNa lead to depolarization, facilitating the generation of cardiac action potentials. Signup and view all the answers

What effects do arrhythmias have on otherwise healthy hearts?

Arrhythmias can occur even in healthy hearts, causing occasional discomfort or serious cardiac symptoms. Signup and view all the answers

Describe the relationship between effective refractory period and action potential duration.

The effective refractory period is typically longer than the action potential duration, limiting the frequency of subsequent action potentials. Signup and view all the answers

What initial effect do diuretics have on blood pressure and how does this change over time?

Diuretics initially lower blood pressure by decreasing blood volume, venous return, and cardiac output, but the hypotensive effect persists even after cardiac output returns to normal due to reduced peripheral resistance. Signup and view all the answers

Explain how thiazide diuretics affect sodium reabsorption and potassium levels in the body.

Thiazide diuretics reduce sodium reabsorption and promote potassium excretion, which can lead to hypokalaemia. Signup and view all the answers

What is the role of calcium in vascular smooth muscle tone, according to the content?

The tone of vascular smooth muscle is influenced by cytosolic Ca2+ concentration, which is increased by α1-adrenoceptor activation. Signup and view all the answers

How do ARBs differ from ACE inhibitors in their effect on blood pressure?

ARBs lower blood pressure by blocking angiotensin receptors and do not cause cough, unlike ACE inhibitors which prevent bradykinin degradation. Signup and view all the answers

What are some potential side effects of thiazide diuretics mentioned in the content?

Thiazide diuretics may cause hypokalaemia, diabetes mellitus, and gout. Signup and view all the answers

Describe the indirect mechanism through which diuretics may lead to reduced vascular smooth muscle responsiveness.

Diuretics may lower smooth muscle Na+, causing a secondary reduction in intracellular Ca2+, which makes the muscle less responsive to endogenous vasoconstrictors. Signup and view all the answers

What is the significance of a small but persistent reduction in body sodium due to diuretics?

A small but persistent reduction in body sodium contributes to long-term blood pressure control and vascular resistance. Signup and view all the answers

Why do ARBs not cause a cough like ACE inhibitors do?

ARBs do not prevent bradykinin degradation, which is believed to be responsible for the cough associated with ACE inhibitors. Signup and view all the answers

What is a common arrhythmia following an acute myocardial infarction?

Sinus bradycardia is commonly seen after acute myocardial infarction. Signup and view all the answers

How do acetylcholine and norepinephrine affect heart rhythm?

Acetylcholine generally slows heart rate while norepinephrine increases it. Signup and view all the answers

What are the two main origins of arrhythmias in the heart?

Arrhythmias can arise from the atrial myocardium or the ventricles. Signup and view all the answers

What might cause an ectopic focus in the heart?

An ectopic focus can occur when a group of cells in the heart fires at a higher rate than the normal pacemaker. Signup and view all the answers

What is the primary concern with many antiarrhythmic drugs?

Many antiarrhythmic drugs can induce lethal arrhythmias, especially in patients with ischemic heart disease. Signup and view all the answers

In the context of antiarrhythmic medications, how are these drugs classified?

Antiarrhythmics are classified based on their electrophysiological effects on Purkinje fibers. Signup and view all the answers

What is the relationship between drug actions on cardiac action potential and therapeutic effects?

The relationship between the electrophysiological effects on cardiac action potential and therapeutic effects is not usually well understood. Signup and view all the answers

What is a potential outcome if cardiac output is lowered?

If cardiac output is lowered, it can lead to various complications, including arrhythmias. Signup and view all the answers

What is the primary function of nitrates in the treatment of angina?

Nitrates primarily work by dilating both venous capacitance vessels and arteriolar resistance vessels, reducing preload and afterload. Signup and view all the answers

Name one specific beta-blocker used in the management of angina.

Bisopropolol is one example of a beta-blocker used for angina. Signup and view all the answers

How do calcium-channel blockers reduce the risk of angina?

Calcium-channel blockers reduce intracellular calcium levels, leading to vasodilation of blood vessels. Signup and view all the answers

What effect does a low LDL/HDL ratio have on heart health?

A low LDL/HDL ratio is associated with a higher risk of coronary artery disease and angina. Signup and view all the answers

What role do antiplatelet drugs play in angina management?

Antiplatelet drugs, like aspirin and clopidogrel, prevent blood clot formation, reducing the risk of heart attacks. Signup and view all the answers

What is the significance of tissue thiols in the action of nitrates?

Tissue thiols facilitate the conversion of nitrates to nitric oxide, a potent vasodilator. Signup and view all the answers

What effect do beta-blockers have on myocardial oxygen demand?

Beta-blockers decrease heart rate and contractility, leading to reduced myocardial oxygen demand. Signup and view all the answers

In terms of vascular smooth muscle, what does calcium do?

Calcium is essential for the contraction of vascular smooth muscle cells. Signup and view all the answers

Describe the relationship between preload and venous return in the context of angina.

Reduced venous return decreases preload, which can alleviate the symptoms of angina. Signup and view all the answers

Name two common side effects associated with the use of nitrates.

Common side effects include headache and hypotension. Signup and view all the answers

How does obesity influence angina risk?

Abdominal obesity is linked with factors like hypertension and diabetes, which increase angina risk. Signup and view all the answers

What is the action of the enzyme guanylyl cyclase in the context of nitrate therapy?

Guanylyl cyclase converts GTP to cGMP, leading to smooth muscle relaxation. Signup and view all the answers

What is one method to manage high blood pressure, which is a risk factor for angina?

Lifestyle changes such as diet, exercise, and medication can help manage high blood pressure. Signup and view all the answers

What physiological changes occur in the coronary arteries during an ischemic event?

During an ischemic event, coronary arteries experience reduced blood flow and increased resistance. Signup and view all the answers

Flashcards

Diuretics

A class of medications that promote urine production, ultimately lowering blood pressure by reducing blood volume, venous return, and cardiac output.

Thiazide diuretics

A group of diuretics that work by blocking the reabsorption of sodium in the distal convoluted tubule of the kidney.

Reduced blood volume

A decrease in blood volume caused by diuretics, leading to a reduction in venous return, which means less blood returning to the heart.