Hypertension Flashcards
What is the main goal of the treatment for hypertension?
A reduction in blood pressure and when this involves drug treatment, should inolve as few side effects as possible.
what are specific goals of the treatment of hypertension?
- 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
What is stage 1 Hypertension?
- 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
What is stage 2 hypertension?
- BP measurement>160/100mmHg & monitoring avg BP is> 150/95
What is severe hypertension?
BP measurement>180mmHg or diastolic bp>110mmHg
How do you treat hypertension?
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
When do you use pharmacological intervention?
- Stage 1 if evidence of organ damage or renal disease/diabetes
* Otherwise lifestyle interventions - Anyone with stage 2 hypertension
Treatment steps for newly diagnosed hypertension.
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
What is ACEI?
- 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)
What are some adverse effects of ACEIs?
- 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.
What are AT1 receptor antagonists?
- 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.
What is Aliskiren?
- New to therapy
- Acts via inhibition of renin (angiotensis activation)
What is Spironolactone?
- Aldosterone receptor antagonist
- Resistant hypertension
- Main use in heart failure
Why are there differences in RAAS activity?
- 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
What are Ca channel blockers?
- Dihydropyridines, e.g. felodipine, nifedipine
- Inhibit voltage gated Ca channels on smooth muscle-> vasodilation and a red in BP
What are Ca channel blockers (NON-DHPs)?
- Verpamil-Blocks cardiac L-type Ca channel (CaV1.2)
- Dec HR and DEc CO
- Diltiazem-effects heart and smooth muscle
What are side effects of Ca channel blockers?
- Constipation-block of smooth muscle in GI tract
- Oedema-Block of smooth muscle in veins
What are diuretics?(1)
- 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+)
What is vasodilation?
- 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
What are diuretics? (2) (problems)
- Dependant on good renal functions
- Ineffective in moderate renal impairment
- Important side effects
1. Hypokalaemia
2. Postural hypotension(standing up-redistribution-dizzy)
What are B-adrenoreceptor antagonists?(beta-blockers)(1)
- 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
What are problems with B-adrenoreceptor antagonists?(beta-blockers)
- 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)
What is propanolol?
- Non-selective for B1 and B2 ARs
What is Atenolol?
- “Selective” but ~5X more selective than B1 over B2 ARs
