medicines used to treat hypertension Flashcards
BP target
systolic below 140 mmHg
diastolic below 90 mmHg
lifestyle modification as first line treatment
- weight reduction
- regular physical exercise
- DASH diet ( rich in veggies/fruits/whole grains)
- reduction of dietary sodium intake
- moderation of alcohol intake
Drugs that act on Beta 1 receptors on juxtaglomerular cells
- propranolol
- bisoprolol
- metoprolol
drugs that act on the angiotensin converting enzyme
ACE inhibitors
- captopril
- enalapril
- lisinopril
- ramipril
drugs that act on angiotensin II receptors
ARBs
- losartan
- valsartan
- candesartan
- irbesartan
drugs that act on the aldosterone receptors
- eplerenone
- spironolactone
Diuretics
Promote diuresis by helping your kidneys release sodium into your urine which helps remove water from your blood decreasing the amount of fluid flowing through your veins and arteries reducing blood pressure
Sympatholytics
Opposes the downstream effects of postganglionic nerve firing in effector organs innervated by the sympathetic nervous system and can have an antihypertensive effect
example: methyldopa (used in Parkinson’s disease)
Drugs that act on vascular smooth muscle
- minoxidil
- nitroprusside
- Ca channel blockers
- thiazides
drugs that act on alpha 1 receptors
- prazosin
- terazosin
- labetalol
drugs that act on renal tubules
- thiazide diuretics
- furosemide
- K+ sparring diuretics
Loop diuretics
Act on the Na/K/Cl cotransporter along the ascending limb of the loop of henle in the kidney
Examples : furosemide, bumetanide, torsemide
Thiazides
- First line treatment for high blood pressure
- they inhibit the apical sodium/chloride transporter in epithelial cells of the distal convoluted tubules to reduce extracellular fluid and cardiac output
Examples : chlorothiazide, hydrochlorothiazide, indapamide
Potassium sparing diuretics
Act to prevent sodium reabsorption in the collecting tubule by either:
- binding epithelial sodium channels (amiloride, triamterene)
- inhibiting aldosterone receptors (spironolactone, eplerenone) preventing excessive potassium in urine and decreasing retention of water
Loop diuretics are more effective than thiazides because
Loop diuretics are more efficacious at producing diuresis and natriuresis because the sodium chloride transporter (which thiazides act on) only reabsorbs 5% of filtered sodium
Diuresis
Condition which kidneys filter too much bodily fluid
Natriuresis
Process which sodium excretion in the urine through the action of the kidneys
Hypokalaemia
Lower than normal potassium level in your bloodstream
Calcium channel blockers - dihydropyridines
Block Ca2+ channels in arterioles preventing calcium from entering the cells allowing blood vessels to relax and open
Examples : nifedipine, amlodipine
Dilation of peripheral vessels causes
Decrease in blood pressure
Dilation of coronary arteries causes
Increased coronary perfusion
Dihydropyridines indirect effects
Lowering blood pressure causes a baroreceptor reflex that stimulates the medulla increasing the firing of SNS to beta receptors in the heart thus increasing heart rate and contractility
not desirable in patients with heart disease
Non-dihydropyridines
- mainly used for heart to slow conduction and decrease contractility for patients with arrhythmias
- can also be used for hypertension - reduced trans-catheter pulmonary valve replacement (TPvR)
Examples : verapamil, diltiazem
Verapamil
Blocks Ca2+ channels in arterioles in the heart
- dilation of peripheral vessels - decreases BP
- dilation of coronary arteries - increases coronary perfusion
- blockade of SA node - decreases heart rate
- blockade of AV node - decreases nodal conduction
- blockade in myocardium - decreases contractile force
