Antihypertensives Flashcards
Give an example of a B1 selective, non-selective and a1 selective Beta-blocker?
B1 selective: Atenolol, Metoprolol
Non-selective: Propanolol
a1-selective: Carvedilol
Describe the MAO of B-blockers?
- Negative chronotropic (HR) and ionotropic (contractility) effects)
- Decreased HR -> decreased cardiac O2 requirement -> adequate myocardial oxygenation
- RAAS: Blocks renin release -> decrease aldosterone -> decrease Na and Cl resorption -> decrease water resorption -> decrease blood volume -> decrease BP
- Peripheral vasodilation
What are the indications for B-blocker use?
Angina, MI, SVT, HTN, HF, glaucoma (Timolol), variceal bleeding (Propanolol)
List B-blocker side effects.
Side effects: erectile dysfunction, cardiovascular (bradycardia, AV block, HF), CNS (seizures, sedation, sleep alterations), dyslipidaemia (metoprolol), asthma/COPD exacerbations
Caution: cocaine users (risk unopposed a-adrenergic receptor agonist activity), concern masking hypoglycaemia in diabetics (benefits outweigh risks)
Give examples of CCBs?
Amlodipine, Nicardipine, Nifedipine
Describe the MAO of CCBs?
- Inhibits Ca influx into cardiac and smooth muscle -> negative ionotropic effect (contractility)
- Slows down electrical conduction -> negative chronotropic effect (HR)
- Relaxation of arterial smooth muscle (vasodilation) -> decrease TPR -> decrease BP
Note: decreased TPR evokes baroreceptor-mediated sympathetic discharge -> increased HR
Name CCB indications?
Angina, HTN, AF, SAH (prevent cerebral vasospasm), Raynoud phenomenon
Give examples of ACEI?
Enalopril, Rimipril, Captopril
Describe the MAO of ACEI?
- Inhibit ACE -> decrease angiotensin II –
- Prevent efferent arteriole constriction -> decrease GFR
- Decrease aldosterone -> diuresis -> decrease BP
- Decrease tubular resorption of Na and Cl
- Also prevents inactivation of bradykinin (potent vasodilator) -> decrease TPR
List indications for ACEI use?
HTN, HF, proteinuria, diabetic nephropathy
Name some ACEI side effects?
SE: cough, angioedema (increased bradykinin), teratogen, increased creatinine (decreased GFR), hyperkalaemia, hypotension
Note: used w caution in bilateral renal a stenosis (further increases GFR -> renal failure)
Give examples of angiotensin II receptor blockers (ARBs)?
Losartan, candesartan, valsartan
Describe the MAO of ARBs?
Selectively block binding of angiotensin II to AT1 receptor
• Prevent efferent arteriole constriction -> decrease GFR
• Decrease aldosterone -> diuresis -> decrease BP
• Decrease tubular resorption of Na and Cl
List indications for ARB use?
HTN, HF, proteinuria, diabetic nephropathy (w ACE-I intolerance)
What are some SE of ARB use?
Hyperkalaemia, decreased GFR, hypotension, teratogen
Give an example of a loop diuretic?
Furosemide, Bumetanide, Torsemide
What is the MAO of Furosemide?
MA: sulfonamide loop diuretics
• Inhibit cotransport system (Na+/K+/Cl-) of thick ascending limb of loop of Henle
• Abolish hypertonicity of medulla -> prevents concentration of urine
• Stimulate PGE release -> vasodilation of afferent arteriole
Note: increased Ca+2 excretion
Inhibited by NSAIDs
List loop diuretic indications?
Oedematous states (HF, cirrhosis, nephrotic syndrome, pulmonary oedema), HTN, hypercalcaemia
List some SE of loop diuretics?
SE (OH DANG acronym): ototoxicity, hypokalaemia, dehydration allergy, metabolic alkalosis, nephritis (interstitial), gout
Give some examples of K-sparring diuretics?
Spironolactone, Triamterene, Amiloride
What is the MOA of K-sparring diuretics?
MA: aldosterone antagonist -> decreased Na+ and Cl- resorption, water retention and increased K+ excretion -> decreased blood volume
List indications for K-sparring diuretic use?
Hyperaldosteronism, K+ depletion, HF, hepatic ascites (Spironolactone), nephrogenic DI (Amiloride)
List some SE of K-sparring diuretics?
Hyperkalaemia (arrhythmia), endocrine w Spironolactone (gynaecomastia, antiandrogen effects)
Give examples of thiazide diuretics?
Hydrochlorothiazide, chlorthalidone, metolazone
