Hypertension

Question 0

Diastolic BP of differing hypertensive serverities and clinical signs

Answer 0

Mild: 90-110, few
Moderate: 100-110, LVH
Severe: >110, LVH, decreased renal function, retinal damage
Malignant: >140, fatal in a few weeks

Question 1

Define hypertension

Answer 1

Increase of systolic and or diastolic BP to point where it increases risk of cardiovascular disease (~140/90mmHg)

Question 2

Secondary hypertension, what is it and what causes it? Treatment?

Answer 2

Caused by an identifiable feature. Treat underlying cause.

Drug induced (contraceptive steroids)…stop pill
Phaeochromocytoma (chromaffin cancer), surgery
Renal stenosis, treat by PCI
Neurogenic stress

Question 3

What is essential hypertension? Treatment?

Answer 3

Unknown underlying cause! 90%. Decrease risk factors (Na, fat, smoking) and drug therapy.

Question 4

Drug therapy? When should it be given?

Answer 4

If 2x readings >90mmHg over a time period or if a >20% coronary risk over 10 years.

Question 5

What would you prescribe to a 55+ white or any age black?

Answer 5

1) Ca++ blocker/diuretic
2) not effective, add ACE/AngII antagonist
3) all 3
4) add b/a blocker

Question 6

What would you prescribe to a <55 white person for hypertension?

Answer 6

1) not effective, add ACE/AngII antagonist
2) Ca++ blocker/diuretic
3) all 3
4) add b/a blocker

Question 7

In hypertension, what happens as a result of increased sympathetic nervous system activity?

Answer 7

1) increase RAA, increase arteriolar tone, increase TPR, increase BP
2) decrease Na and water excretion, increase BV, increase CO, increase BP
3) increase CO, increase BP

Question 8

5 treatments for hypertension?

Answer 8

1) diuretics
2) sympatholytics
3) centrally acting anti hypertensives
4) vasodilators
5) renin angiotensin inhibitors

Question 9

Explain the use of diuretics in treating hypertension, giving examples of drugs.

Answer 9

Increase sodium excretion, increase fluid excretion, decrease plasma volume, decrease TPR, decrease BP.

Thiazides eg bendromethiazide.
Act at DT, on Na/Cl cotransporter BUT, Potassium loss, increase cholesterol and hyperglycaemia

K+ sparing eg spironalactone (aldosterone antag)...gynecomastia
Eg amiloride (ENaC blocker)...hyperkalemia!

Question 10

Explain the use of sympatholytics in treating hypertension, giving examples of drugs.

Answer 10

Block effects of S-NS.

Beta antagonists: decrease CO and renin secretion.

Non selective b: propranolol
B1 selective: metoprolol…but bronchospasm, raynauds, rebound hypertension, bizarre dreams (cross BBB), increase plasma fats, decrease gluc tolerance, decrease hyperglycaemia warning signs!

Alpha 1 antag: prazosin…Inhibit NA, dilate arteries, decrease TPR. But initial fainting and dizziness.

A and b non selective. Labetalol (postural hypotension) and carvedilol.

Question 11

Explain the use of centrally acting antihypertensives in treating hypertension, giving examples of drugs.

Answer 11

Dopa-dopamine-noradrenaline.

Alpha 2 agonists stimulate negative feedback inhibiting nAdr release. Eg, chlonidine

Or…prodrug alpha-methyl-DOPA, converts to a-methyl-NA which also is an a2 agonist!

Question 12

Explain the use of vasodilators in treating hypertension, giving examples of drugs.

Answer 12

Act on SM of arterioles…decrease TPR and BP but baroreceptor reflex and fluid retention so use with beta blockers and diuretics!

1) VOCC blockers. No Ca in to sm, vasodilation (amlodipine…but headaches and postural hypotension)
2) K+ channel activating drugs…open channels, potassium efflux, hyper polarise, VOCC close (minoxidil…headaches, sweating)

And sodium nitroprusside for hypertensive emergency. Nitro vasodilator….cGMP.

Question 13

Explain the use of renin angiotensin blockers in treating hypertension, giving examples of drugs.

Answer 13

B blockers to inhibit renin release

Ace inhibitors…captopril…bad taste, dry mouth, sinusitis

Ang II antagonists…losartan…bad taste, head ache, raise plasma potassium But, no bad cough as doesn’t interfere with bradykinin metabolism!