Untitled Quiz

Drugs Used in Hypertension

• Diuretics: Reduce blood pressure by decreasing blood volume and directly affecting blood vessels.

  • Thiazide Diuretics: Inhibit sodium and chloride transport in the Distal Convoluted Tubules.
    • Examples: Hydrochlorothiazide, Chlorthalidone, and Metolazone
    • Uses: Hypertension and heart failure.
    • Side Effects: Hypokalemic metabolic acidosis.
  • Loop Diuretics: Inhibit sodium, potassium, and chloride transport in the thick ascending loop of Henle.
    • Examples: Furosemide, Torsemide, and Ethacrynic Acid.
    • Uses: Heart failure and pulmonary edema
    • Particularly effective in edematous states and fluid overload.
    • Side Effects:
      • Ototoxicity (hearing loss)
      • Hypokalemia (low potassium)
      • Dehydration
      • Allergy to Sulfa
      • Nephritis (kidney inflammation)
      • Gout (arthritis)

• Sympathoplegics: Interfere with the sympathetic nervous system's control of cardiovascular function.

  • By reducing: venous tone, heart rate, contractile force of the heart, cardiac output and total peripheral resistance.
  • Uses: Hypertension, Pre-eclampsia.
  • Examples: Clonidine, Alpha-1 blockers, and Beta Blocks.

  Sympathoplegics

• Centrally Acting Alpha 2 Agonists: Stimulates alpha-2 receptors in the central nervous system to reduce sympathetic outflow.

  • Clonidine: Reduces heart rate and relaxes blood vessels.
    • Side Effects: Rebound hypertension and dry mouth.
    • Taper before discontinuing to avoid rebound hypertension.
  • Methyldopa: Used for maintenance treatment of hypertension in pregnancy.
    • Side Effects: Hemolytic anemia.

• Adrenergic Blockers: Block receptors for the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline) to reduce their effects.

  • Alpha Adrenergic Blockers: Block alpha-1 receptors, primarily located in the blood vessels and smooth muscle.
    • Examples: Prazosin, Doxazosin, Terazosin, Tamsulosin, Silodosin, Alfuzosin.
    • Uses: Benign Prostatic Hyperplasia (enlarged prostate gland).
    • Side Effects: First dose syncope (fainting) and orthostatic hypertension (low blood pressure upon standing).
    • Tamsulosin: Most selective for prostatic smooth muscle.
  • Beta Adrenergic Blockers: Block beta receptors, located on the heart and other tissues.
    • Examples: Metoprolol, Propanolol, Atenolol, Nebivolol, Esmolol, Carvedilol.
    • Uses: Hypertension, Migraine, Glaucoma.
    • Side Effects: Heart Failure, erectile dysfunction
    • Must not be given in acute heart failure
    • Can be used in chronic heart failure.

Vasodilators

• Medications that open/dilate blood vessels.
  • Effects: Relaxes muscles in the walls of arteries and veins, preventing them from tightening and narrowing.
  • Result: Blood flows more easily and the heart doesn't have to pump as hard, reducing blood pressure.

Vasodilators

• Oral Vasodilators
  • Hydralazine:
    • Uses: Preeclampsia, Hypertension.
    • Side Effects: Severe psychiatric depression, suicidal ideation.
  • Minoxidil:
    • Uses: Alopecia (hair loss), Hypertension.
    • Side Effects: Hirsutism (excessive hair growth), Angina, Drug-induced lupus.
    • Stimulates hair follicles.

Vasodilators

• Parenteral Vasodilators
  • Nitroprusside:
    • MOA: Relaxes venous and arteriolar smooth muscle by increasing nitric oxide (NO) → ↑ cGMP → smooth muscle relaxation.
    • Uses: Hypertensive emergency, Acute heart failure.
    • Side Effects: Cyanide toxicity, hypotension, headache.
    • Most effective vasodilator.
  • Fenoldopam:
    • MOA: Arteriolar vasodilation of afferent (incoming) and efferent (outgoing) arterioles. Increases renal blood flow.
    • Uses: Hypertensive emergency.
    • Side Effects: Hypotension, Hypokalemia.

Calcium Channel Blockers

• Medications that lower blood pressure and treat symptoms such as chest pain and irregular heartbeat.

• Block the L-type calcium channels in the body.

• Stops calcium from entering the cells of the heart and the arteries.

• Calcium causes the heart and arteries to squeeze more strongly.

• By blocking calcium, CCBs allow blood vessels to relax and open.

• Types of Calcium Channel Blockers:

  • Non-dihydropyridine CCB:
    • Verapamil, Diltiazem.
  • Dihydropyridine CCB:
    • Amlodipine, Nicardipine.

• Common Side Effects: Constipation, Pretibial Edema.

Calcium Channel Blockers

• Non-Dihydropyridine CCB
  • Verapamil:
    • MOA: Cardiac > Vascular
    • More cardioselective CCB
    • Preferred CCB for arrhythmia
    • Uses: Supraventricular tachycardia (SVT)
    • Side Effects: Gingival hyperplasia (Verapamil) (gum overgrowth).

Calcium Channel Blockers

• Dihydropyridine CCB
  • Amlodipine, Nifedipine, Felodipine, Nicardipine.
  • MOA: Vascular > Cardiac
  • Common Uses: Hypertension-related chest pain (Angina)
  • Side Effects: Edema, Flushing, Dizziness