Hypertension 2

Question 1

What are calcium channel blockers used for, and which drugs are used specifically?

Answer 1

Hypertension- amlodipine, felodipine, nifedipine, lacidipine
Ischaemic heart disease- diltiazem, verapamil
Arrythmia (same as IHD)

Question 2

What are the classes of calcium channel blockers and what are their actions?

Answer 2

Dihydropyridines- nifedipine, amlodipine, felodipine, lacidipine
peripheral arterial vasodilators
Phenylakylamines- verapamil
main effects on the heart, negatively chronotropic, negatively inotropic
Benzothiazepines - diltiazem
immediate heart/ peripheral vascular effects

Question 3

What are the adverse effects of calcium channel blockers?

Answer 3

Due to peripheral vasodilation:
flushing, headache, oedema, palpitations (reflex tachycardia)
Due to negatively chronotropic effects (verapamil and diltiazem):
bradycardia, atrioventricular block
verapamil causes constipation- effect on GI smooth muscle

Question 4

Examples of alpha blockers and adverse effects

Answer 4

Doxazosin, indoramin, terazosin, prazosin

-postural hypotension- stand up and feel dizzy/ might collapse

Question 5

What can alpha blockers be used to treat? (as well as HT)

Answer 5

Benign prostatic hypertrophy
alpha receptors in the muscle surrounding the prostate
relaxes the smooth muscle in the prostate and bladder -alfuzosin and tamsulosin

Question 6

Examples of centrally acting drugs and their effects

Answer 6

Moxonidine- new
Methyldopa- old, acts on presynaptic alpha 2 receptors, number of actions, safe for pregnancy
Clonidine- impairs noradrenaline release

Question 7

Example of a renin inhibitor and its adverse effects

Answer 7

Aliskiren- widely used
adverse effects (in keeping with ACE-Is and ARBs):
hyperkalaemia, dizziness, arthralgia, diarrhoea

Question 8

Why does treatment differ from old to young?

Answer 8

To do with renin driven hypertension

older= BP problems less likely to be driven by RAAS- same with afro-Caribbeans (low renin)

Question 9

What are the steps of HT treatment?

Answer 9

Step 1 (under 55): ACE-I or ARB
Step 1 (over 55 or afro-c): calcium channel blocker 
Step 2: if ACE-1 didnt work use ARB and vice versa- add a CCB- works synergistically 
Step 3: add a thiazide- like diuretic (used to be a thiazine one) (dont used loop diuretics)- less potent, longer acting diuretic 
Step 4: Resistant hypertension- consider the addition of:  spironolactone, high dose thiazide-like diuretic, alpha blocker, beta blocker