Hypertension

Question 1

What is the main goal of the treatment for hypertension?

Answer 1

A reduction in blood pressure and when this involves drug treatment, should inolve as few side effects as possible.

Question 2

what are specific goals of the treatment of hypertension?

Answer 2

• Red in cardiovascular damage
• Preservation of renal function
• Limitation or reversal of left ventricular hypertrophy
• Prev of IHD
• Red in mortality due to stroke and MIs

Question 3

What is stage 1 Hypertension?

Answer 3

• BP measurement > 140/90mmHg
• Patient given ambulatory BP monitoring (ABPM) or home BP monitoring (HBPM) in the daytime over 1 week.
• Hypertension if avg ABPM or HBPM bp>135/85

Question 4

What is stage 2 hypertension?

Answer 4

• BP measurement>160/100mmHg & monitoring avg BP is> 150/95

Question 5

What is severe hypertension?

Answer 5

BP measurement>180mmHg or diastolic bp>110mmHg

Question 6

How do you treat hypertension?

Answer 6

Lifestyle changes play a central and primary role:
* Red overall cardiovascular risk:
1. Alcohol consumption red-huge component
* Weight reduction
* Red excess caffeine
* Red fat and salt intake-DASH diet
* Inc fruit and oily fish in the diet
* Inc excercise
* smoking cessation

Question 7

When do you use pharmacological intervention?

Answer 7

1. Stage 1 if evidence of organ damage or renal disease/diabetes
   * Otherwise lifestyle interventions
2. Anyone with stage 2 hypertension

Question 8

Treatment steps for newly diagnosed hypertension.

Answer 8

Step 1: (If < 55Yo) ACEinhib
Step 1: (if >55yo or black pt) Ca2+ channel blocker
Step 2: ACEI + Ca2+ channel blocker
Step 3:ACEI + Ca2+ channel blocker + thiazide
Step 4:Add further diuretic, A-blocker or B-blocker

Question 9

What is ACEI?

Answer 9

• Angiotensin-converting enzyme inhibitor (e.g. captopril, enalapril, lisinopril etc)
• Inhibits the enzyme that converts angiotensin 1 into angiotensin 2
• Angiotensin 2 leads to vasoconstriction and aldosterone production-(leads to red in salt and water retention)
• (also potentiate bradykinin-cough)
• (Bradykinin:Vasodilator-cont to dec BP)

Question 10

What are some adverse effects of ACEIs?

Answer 10

• Cough in 10% of patients
• First dose hypotension
• May inc potassium-effects on kidney
• Angioedema-swelling of lips, tongue, and face.
• Bradykinin inc the permeability of blood vessels-more fluid into tissues.

Question 11

What are AT1 receptor antagonists?

Answer 11

• e.g. candesartan,losartan
• Block action of A-II at AT1 receptor
• These agents have similar consequences as ACEIs but do not give rise to the cough.

Question 12

What is Aliskiren?

Answer 12

• New to therapy
• Acts via inhibition of renin (angiotensis activation)

Question 13

What is Spironolactone?

Answer 13

• Aldosterone receptor antagonist
• Resistant hypertension
• Main use in heart failure

Question 14

Why are there differences in RAAS activity?

Answer 14

• Drugs targeting RAAS are less effective in black patients. incl. aliskiren
• Lower renin activity
• Leads to inc salt and water retention in the kidney-inc risk of hypertension in black patients
• Diuretics more effective in black patients as a result

Question 15

What are Ca channel blockers?

Answer 15

• Dihydropyridines, e.g. felodipine, nifedipine
• Inhibit voltage gated Ca channels on smooth muscle-> vasodilation and a red in BP

Question 16

What are Ca channel blockers (NON-DHPs)?

Answer 16

• Verpamil-Blocks cardiac L-type Ca channel (CaV1.2)
• 1. Dec HR and DEc CO
• Diltiazem-effects heart and smooth muscle

Question 17

What are side effects of Ca channel blockers?

Answer 17

• Constipation-block of smooth muscle in GI tract
• Oedema-Block of smooth muscle in veins

Question 18

What are diuretics?(1)

Answer 18

• Thiazide-like e.g. chloratidone and indapamide
• Thiazides (e.g. bendroflumethiazide)
• Inhibit Na+/Cl- reabsorption in distal convoluted tubule
• Leads to diuresis
• Red in circulating vol-red BP
• Hypokalaemia (dec K+)

Question 19

What is vasodilation?

Answer 19

• Mechanism not clear.
• Continues after diuretic effect has finished(body adapts after 4-6 weeks)
• Direct effect on smooth muscle or endothelium?
• Indirect through reduction in plasma volume?

See PP

Question 20

What are diuretics? (2) (problems)

Answer 20

• Dependant on good renal functions
• Ineffective in moderate renal impairment
• Important side effects
  1. Hypokalaemia
  2. Postural hypotension(standing up-redistribution-dizzy)

Question 21

What are B-adrenoreceptor antagonists?(beta-blockers)(1)

Answer 21

• E.g. atenolol,propanolol
• Block action of noradrenaline(and adrenaline) on heart
• B1 ARs in SAN-blockers dec rate of contraction
• B1 ARs in ventricles muscle and atria-blockers dec force of contraction
• Dec CO

Question 22

What are problems with B-adrenoreceptor antagonists?(beta-blockers)

Answer 22

• Limited by the fact that B-adrenoreceptors on vascular smooth muscle casues vasodilation
• Not first line treatment for hypertension, but useful in cardiac ischaemia (e.g. angina)
• Antagonise B-adrenoreceptors in airways-bronchoconstriction
• Mainly B2 adrenoreceptors in airways, B1 adrenoreceptors in heart (but not exclusive)
• Contraindicated in asthma (exacerbate breathing issues)

Question 23

What is propanolol?

Answer 23

• Non-selective for B1 and B2 ARs

Question 24

What is Atenolol?

Answer 24

• “Selective” but ~5X more selective than B1 over B2 ARs

Question 25

Side effects of Beta-blockers?

Answer 25

• Bronchospasm
• Red hypoglucaemic awareness

Question 26

What are a-adrenoreceptor antagonists?

Answer 26

• a1-adrenoreceptors-present on vascular smooth muscle-causes vasoconstriction
• Antagonists e.g. doxazosin, prazosin
• Competitive receptor antagonists pf a1-adrenoreceptors
• Last choice antihypertensives
• 1. Widespread side effects, which makes them poorly tolerated.

Question 27

When are Beta-blockers used?

Answer 27

• In patient with angina or past MI
• Child bearing
• Inc sympathetic drive
• Intolerance to ACEIs/ATRA