Drugs to treat hypertension

Question 1

Diltiazem, Nifedipine, Verapamil

Answer 1

antagonists to voltage-gated L-type calcium channels, thus reducing smooth muscle contraction. Combats the effects of noradrenaline (sympathetic NS), causing vasodilatation and decreased blood pressure.
reduce contraction of vasculature and the heart
Hypertension, angina
Hyper tension,angina, dysrhythmias

Question 2

Mannitol:

Answer 2

osmotic diuretic. Metabolically inert sugar that can pass through the glomerulus into the nephron, but not be reabsorbed. This alters the osmolarity of urine and prevents water being reabsorbed. It is the only diuretic acting outside the nephron lumen. Given by IV injection. !Reduce BP, intracranial and ocular pressure, renal failure

Question 3

Frusemide, Bumetanide:

Answer 3

loop diuretics (act in the Loop of Henle). Inhibits NKCC2, a cotransporter that moves 1 Na+, 1 K+ and 2 Cl- from the nephron lumen into cells of the ascending limb. This stops ions being taken out of the urine and so water cannot be reabsorbed from the descending loop (the ascending loop is impermeable to water). Use confined to cases where the kidneys are not functioning
Mostly used against secondary hypertension and renal failure ,

Question 4

Bendroflumethiazide, Chlorthalidone:

Answer 4

thiazide diuretics. Act by inhibiting the Na+/ Cl- cotransporter in the distal convoluted tubule. This reduces salt reabsorption and so, increased NaCl is passed to downstream segments of the nephron. Urine is more concentrated and less water reabsorbed. Weak diuretics on their own,
Mostly used against secondary hypertension and renal failure

Question 5

Spironolactone:

Answer 5

potassium-sparing diuretic. Competitive antagonist of aldosterone, therefore decreasing sodium movement and decreasing water reabsorption
Weak diuretics on their own,
Used accompanied by other diuretics to reduce the K loss

Question 6

Amiloride, Triamterene:

Answer 6

potassium-sparing diuretics. Block sodium channels in the lumen membrane, reducing sodium movement ! reducing water reabsorption and potassium loss

Question 7

Captopril, Enalapril, Ramipril:

Answer 7

(ACE inhibitors): competitive inhibitors of ACE enzyme. ACE enzyme is required to activate angiotensin, which is required for aldosterone secretion and subsequent vasoconstriction. These drugs therefore reduce vasoconstriction. But, causes initial hypotension and a cough
Antihypertensive drug
Coughing side effect due to bradykinin

Question 8

Losartan, Valsartan:

Answer 8

competitive antagonists at ATII (angiotensin II) receptors, therefore blocking angiotensin II. No angiotensin II = no aldosterone and reduced vasoconstriction. Causes initial hypotension but no cough.

Question 9

Propanolol:

Answer 9

competitive antagonist at β adrenoceptors (non-selective between β1 and β2). Reduces heart rate and vasoconstriction. Lipid soluble so can penetrate the CNS (not great).

Question 10

Atenolol:

Answer 10

competitive, relatively selective, antagonist of β1 receptors (reduces heart rate). Water soluble so has poor CNS penetration (good).
(Blocking β1 receptors of kidneys also reduces renin secretion, so reducing aldosterone secretion)

Question 11

Systolic -

Answer 11

• pressure while heart is contracting (maximum pressure)

Question 12

Diastolic

Answer 12

the presuure whilst heart is filling (min pressure)

Question 13

Pulse pressure?

Answer 13

Difference between systolic and diastolic

Question 14

Hypertension

Answer 14

Increased diastolic pressure
Increased systolic pressure
Increased pulse pressure

Question 15

Hypotension -

Answer 15

decreased BP

Question 16

Causes of secondary hypertension

Answer 16

• phaeochomocytoma (adrenal medulla tumour)
• renal artery stenosis
• polycystic renal disease