quiz 2 306

Mechanism of action

1. ARBs

angiotensin II receptor blockers

block AT1 receptors → prevent angiotensin II from causing:

• vasoconstriction and aldosterone release,

  • resulting in vasodilation and lower BP

• They do not affect bradykinin,(No increase) does not cause a cough

2. ACE inhibitors

Block angiotensin-converting enzyme

ACE inhibitors block the conversion of angiotensin I to angiotensin II

• causing blood vessels to relax and lowering BP.

• increase bradykinin, which promotes additional vasodilation

bradykinin has a cough

3. SA node modulators (ivabradine)

Ivabradine blocks HCN channels in the SA node,

• slowing spontaneous depolarization which means is slows:

• slows the heart rate and increasing filling time without affecting:

  • BP

  • heart contractility (more blood per beat)

4. Cardiac glycosides (digoxin)

It inhibits Na⁺/K⁺-ATPase, which increases intracellular Na⁺:

• Na⁺/Ca²⁺ exchanger to reverse,

  • leading to an increase in intracellular Ca²⁺.

• result is positive inotropy ( increased contractility).

• It also increases parasympathetic (cholinergic) tone, which decreases heart rate and slows AV conduction

5. Angiotensin Receptor (Neprilysin Inhibitors (ARNi)

ARNi (valsartan/sacubitril)

Sacubitril inhibits neprilysin, which increases natriuretic peptides and causes

• vasodilation and natriuresis

Valsartan blocks the AT₁ receptor, which prevents angiotensin II–induced -

• vasoconstriction, aldosterone release, and catecholamine release.

  • reduce cardiac remodeling and volume overload.

6. Adrenergic drugs (3)

alpha 1 blocker (selective)

ends with -osin (doxazosin, prazosin, terazosin)

Mechanism: Blocks α1​-adrenergic receptors, preventing norepinephrine from constricting smooth muscle.

• Vascular Effects: Relaxes blood vessels to lower BP

• Prostatic Effects: Relaxes smooth muscle in the prostate and bladder neck, improving urinary flow in Benign Prostatic Hyperplasia (BPH).

beta blockers

Beta-blockers bind to β-adrenergic receptors and block the effects of adrenaline and noradrenaline

• β₁ blockade decreases heart rate and contractility.

• Non-selective β-blockers also block β₂ receptors, which contributes to lowering blood pressure.

• reduced cardiac output

• Metoprolol is β₁-selective

• Propranolol is non-selective (β₁ and β₂).

combination alpha and beta blockers

7. Calcium channel blockers (CCBs)

Blocks L-type calcium channels, reducing calcium entry into cardiac and vascular smooth muscle.

• Decreases HR and contraction force, lowering the heart's oxygen demand.

• Relaxes blood vessels to lower BP and improves coronary blood flow to relieve angina.

8. Selective aldosterone blockers

These are Aldosterone Antagonists / Potassium-Sparing Diuretics (e.g., spironolactone, eplerenone):

Blocks aldosterone receptors in the kidney's collecting duct, preventing sodium reabsorption and potassium excretion.

• mild diuresis (fluid loss) while retaining potassium, which lowers BP without dropping potassium levels.

• Reduces cardiac fibrosis (tissue scarring), offering critical protective benefits in heart failure management

9. antianginals

Nitrates

It is converted to nitric oxide (NO), which:

• activates guanylyl cyclase and increases cGMP.

• This causes smooth muscle relaxation, leading to venodilation (decreased preload) and arterial dilation (decreased afterload),

  • which lowers myocardial oxygen demand.

• It also inhibits platelet aggregation and has anti-inflammatory effects.

10. diuretics (5)

loop

This drug blocks a “salt pump” (NKCC2) in the kidney that normally reabsorbs sodium and chloride back into the body.

• It makes the kidneys remove more salt and water from the body, causing strong urine output (diuresis).

Thiazide diuretics

Blocks the sodium-chloride (salt) transporter in the distal tubule of the kidney. This causes more sodium and water to leave the body in urine, which lowers blood volume and blood pressure. It also makes the body keep more calcium by increasing calcium reabsorption.

thiazide-like

potassium-sparing

They prevent potassium (K⁺) loss while still allowing sodium (Na⁺) to be excreted.

These drugs help the body get rid of sodium but keep potassium from being lost in the urine. Spironolactone blocks aldosterone, and amiloride and triamterene block sodium channels in the kidney. This causes mild fluid loss and can raise potassium levels in the blood (high potassium)

osmotic

carbonic anhydrase inhibitors

11. Endothelin receptor blockers

12. Coagulation Modifiers (3)

oral anticoagulants

heparin

Heparin binds to antithrombin III and makes it work faster. This increases the inactivation of clotting factors like thrombin (IIa) and factor Xa, which prevents clot formation. It is monitored using aPTT, and the antidote is protamine sulfate.

low molecular weight heparin

These drugs mainly block factor Xa through antithrombin III, which prevents clot formation. They have more predictable effects than unfractionated heparin, so they usually do not need regular lab monitoring. They are given by subcutaneous injection. An example is enoxaparin (Lovenox).

antiplatelets

Aspirin blocks COX-1 and COX-2,

• lowers thromboxane A2 and makes platelets less likely to stick together.

• Clopidogrel blocks the P2Y12 receptor on platelets, so they cannot activate and clump.

• Both drugs reduce clot formation. A major side effect of all these drugs is bleeding.

drug class

1. lisinopril

ACE inhibitor.

lower BP by blocking angiotensin II, which reduces sodium and water retention while sparing potassium

Used for hypertension

lisinopril is active immediately, though all require lower doses in patients with kidney disease. Once taken, lisinopril takes effect in 1 hour, peaks in 6 to 8 hours, and lasts for a full 24 hours.

what is ace inhibitors/liinopril used to treat?

By suppressing the RAAS (renin-angiotensin-aldosterone system), ACE inhibitors help prevent/treat:

• Hypertension (high blood pressure)

• Heart failure

• Diabetic nephropathy (kidney disease)

• Myocardial infarction (heart attack)

exerted in the kidneys

major adverse effects

Valsartan

ARBs are generally well-tolerated, but some possible side effects include:

• dizziness,

• headache,

• fatigue,

• diarrhea

• high potassium levels.

• The ACEI cough is generally not a problem

enalapril

ACE inhibitors

cough, hypotension, angioedema (rare but serious)

metoprolol

beta blockers

• bradycardia (slow heart rate)

• hypotension)

• dizziness,

• fatigue,

• cold hands and feet,

• difficulty sleeping,

• nightmares

• sexual dysfunction

propranolol

beta blockers

• bradycardia (slow heart rate)

• hypotension)

• dizziness,

• fatigue,

• cold hands and feet,

• difficulty sleeping,

• nightmares

• sexual dysfunction

verapamil

Calcium channel blockers (CCB)

• constipation (especially verapamil),

• peripheral edema or swelling in the arms and legs (amlodipine, nifedipine),

• slow heart rate

• hypotension

• Fatigue

• , flushing,

• dizziness can also occur

ivabradine

Sinoatrial (SA) node modulators

Major side effects can be bradycardia and hypotension

digoxin

antihypertension drugs (heart failure)

cardiac glycoside

bradycardia, hypokalemia, cardiac arrhythmias and cardiac arrest can occur with

toxicity

nitroglycerin

Antianginal drugs

include headache, flushing, hypotension

furosemide

loop diuretics

primarily Hypokalemia (low potassium levels),

Hyponatremia (low sodium levels),

Hypochloremia (low chloride levels),

and Hypomagnesemia (low magnesium levels).

dehydration,

orthostatic hypotension (low blood pressureupon standing), dizziness, and fatigue

heparin

Anticoagulant drugs

The major side effect of all the coagulation modifier drugs is bleeding.

hydralazine/isosorbide dinitrate

antihypertension (ACEs, ARBS, and Beta Blockers)

Vasodilators

headache, dizziness, and hypotension

hydrochlorothiazide (HCTZ

Thiazide and thiazide-like diuretics

hypokalemia

hyponatremia

metabolic alkalosis

hypercalcemia hyperglycemia

hyperuricemia

Valsartan/Sacubitril

Angiotensin receptor/Neprilysin inhibitors (ARNIs

warning regarding its use in pregnancy category D

severely low blood pressure, high potassium levels (hyperkalemia), kidney problems, and dangerous allergic reactions (angioedema