hypertension Flashcards
Pharmacological treatment of HTN:
- Angiotensin converting enzyme inhibitors (ACE inhibitors “prils”)
- Angiotensin II receptor antagonists (A2RA or “sartans”)
- Calcium channel blocking agents
- Beta adrenoceptor antagonists (beta-blockers or ‘lol”)
- Thiazide diuretics
hypertension is a cardiovascular risk factor
High blood pressure is a major risk factor for heart disease. It is a medical condition that happens when the pressure of the blood in your arteries and other blood vessels is too high. The high pressure, if not controlled, can affect your heart and other major organs of your body, including your kidneys and brain
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diabetes
MI
Non-pharmacological treatment of HTN
- Non-pharmacological measures first – lifestyle, diet, physical activity, reduction of alcohol, healthy eating, management of OSA, smoking cessation, moderate sodium restriction, weight reduction
- Mediterranean diet – mono, poly, omega 3 datty acids / reduced intake of saturated fat. Lots of fruits, veg, nuts, vegetables, pasta, olives, olive oil. Limited red meat, processed foods
- Low fat not always good. Mono, poly, omega 3 fats are good. Some low-fat products have high levels of sugars
ACE Inhibitors
- Inhibit ACE (the enzyme that converts angiotensin I to II) + inhibit the breakdown of bradykinin
- Reduce vasoconstriction, sodium reabsorption, aldosterone release
Produce a drop in BP by:
- Inhibiting the production of Angiontensin II leading to vasodilation + a drop in peripheral resistance
- Reducing the secretion of aldosterone leading to diuresis + sodium loss
- Increasing bradykinin levels leading to vasodilation + a drop in peripheral resistance
ACE Inhibitors side effects
- Cough
- Orthostatic (postural) hypotension – dizziness
- Hyperkalaemia
Angiotensin II Receptor Antagonists
- Prevent angiontensin II from binding to type 1 angiotensin (AT1) receptors on blood vessels – they have the same result as ACE inhibitors
- Reduce vasoconstriction, sodium reabsorption, aldosterone release
Produce a drop in BP by:
- Inhibiting angiotensin II induced vasoconstriction leading to vasodilation + a drop in PR
- Inhibiting the secretion of aldosterone leading to diuresis and sodium loss
Angiotensin II Receptor Antagonists side effects
- Orthostatic hypotension, dizziness
- Hyperkalaemia
Calcium Channel Blocking Agents (calcium channel blockers)
Dihydropyridines: primarily inhibit calcium entry into the vascular smooth muscle cells of blood vessels
Non-dihydropyridines: inhibit calcium entry into the vascular smooth muscle cells of blood vessels + cells in the heart, GIT
calcium channel blockers side effects
Dihydropyridines
- Hypotension, headache, flushes, reflux, peripheral oedema (ankle)
Non-dihydropyridines:
- Bradycardia e.g. diltiazem, verapamil
- Constipation e.g. verapamil
examples of CCB
Dihydropyridines: Amlodipine, clevidipine, nifedipine
Non-dihydropyridines: diltiazem, verapamil
Beta Adrenoceptor Antagonists
- Block beta receptors in heart (B1 receptor), lungs (B2 receptor), bladder (B3 receptor) etc
- Reduce HR, BP, cardiac contractility
- Depress sinus node rate and slow conduction through AV node
Cardio-selective BBs: just block beta 1 receptors BUT in high doses they may also block beta 2 and 3
MOA in reducing BP (not fully understood):
- Blocks beta 1 receptors in kidneys – reduces renin release
- Blocks beta 1 receptors in heart – reduces CO
- Reduce peripheral resistance
BB side effects
- Wheezing, acute asthmatic attacks in pts with asthma
- Bradycardia, fatigue, reduced exercise tolerance
- Cold extremities, aggravation of Raynauds
- Sleep disturbances, nightmares, impotence
examples of BB
Non-selective BBs: Propranolol, bisoprolol
Cardio-selective BBs: atenolol, metoprolol
Diuretics MOA
- Inhibit the uptake (reabsorption) of sodium at different sites in the renal tubules – more sodium is excreted in urine
- Increase osmotic pressure in the renal tubules + reduce passive reabsorption of water
Loop diuretics: potent, site: LOH
Thiazide diuretics: moderately potent, site: distal convoluted tubule
Potassium sparing diuretics: weak diuretics, site: late distal convoluted tubule
diuretics side effects
Thiazide diuretics: hypokalaemia, hyponatraemia, hyperuricaemia, precipitate gout, hyperglycaemia, urinary frequency/urgency
Loop diuretics: hypokalaemia, hyponatraemia, hyperuricaemia, precipitate gout, hyperglycaemia, urinary frequency/urgency
Potassium sparing diuretics: hyPERkalaemia, gynaecomastia in men
