Hypertension Flashcards
(43 cards)
Hypertension Cause
Largely unknown but multifactorial.
Hypertension definition
A BP associated with significant cardiovascular risk
Secondary hypertension causes (8)
Less common (<10%) is secondary hypertension, it is due to another disease:
- Renal disease
- Reno vascular disease
- Cushing’s syndrome
- Conn’s syndrome
- Hyperthyroidism
- Phaeochromocytoma
- Pregnancy
- Drugs - e.g. NSAIDS, corticosteroids, venlafaxine, ciclosporin, sympathomimetics
Hypertension Treatment Goals - General
A reduction in BP (and when this involves drug treatment, this should be with as few side effects as possible).
Hypertension Treatment Goals - NICE
SBP < 140 mmHg
DBP < 90 mmHg (<80 in diabetes)
Hypertension Treatment Goals - Specific (5)
- Reduction in cardiovascular damage
- Preservation of renal function
- Limitation/ reversal of left ventricular hypertrophy
- Prevention of IHD
- Reduction in mortality due to stroke/ MIs.
RAAS
Mechanism of ACEIs
Inhibit Angiotensin Converting Enzyme and therefore halt production of Angiotensin 2
Example ACEIs
e.g. captopril, enalapril, lisinopril, perindopril, ramipril
ACEI/ Reduction in A2 - Consequences (5)
- Reduction in arterial and venous vasoconstriction
- Reduced aldosterone production leads to reduced salt & water retention
- Also potentiate bradykinin (usually broken down by ACE) - COUGH
- May increase potassium - interaction with salt (KCl) substitute
- Angioedema - rapid swelling (edema) of the dermis, subcutaneous tissue, mucosa and submucosal tissues.
ACEIs - Renal consequences
Should be AVOIDED in RENOVASCULAR DISEASE:
RAAS & Renin-dependent hypertension, ACEIs lead to underperfusion and severe hypotension.
May lead to worsening of renal function - if this occurs discontinue! Monitor creatinine before & during use.
Conversley ACEIs effective in PREVENTION OF NEPHROPATHY in DM - may be agents of choice in diabetes pts.
AT1R Antagonists - Action & Examples
e.g. Candesartan, losartan, valsartan
BLOCK action of A2 at AT1 receptor
AT1 receptor antagonist
Similar consequences as ACEIs but do not give rise to a cough.
Calcium Channel Blockers - Examples
e.g. diltiazem, verapamil, dihydropyridines (amlodipine, felodipine, nifedipine)
Calcium Channel Blockers - Action
Vasodilators
Inhibit Voltage gated Calcium channels on vascular smooth muscle, leading to vasoldilation, and a reduction in BP.
VERAPAMIL - exerts most of its effects on the heart
compared with
DIHYDROPYRIDINE effects -
which are greater on arteriole smooth muscle.
ALPHA BLOCKERS - Examples
e.g. doxazosin, prazosin
ALPHA BLOCKERS - Action
Competitive receptor antagonists of alpha-1 adrenoceptors.
Last choice antihypertensives:
widepread side effects therefore poorly tolerated.
Diuretics: Thiazide-like Examples
e.g. chlortalidone and indapamide
Thiazides: Example, use & action (3).
e.g. bendroflumethiazide
THIRD line antihypertensives.
- Inhibit NA+/Cl- in distal convoluted tubule
- Reduction in circulating volume
- Also causes vasodilation
Thiazides: Caution & Side Effects
Ineffective in moderate renal impairment (except metolazone).
Measure renal function (creatinine) before and during use.
SIDE EFFECTS:
Hypokalaemia
Postural hypotension
Impaired glucose control
Do NOT use in Gout
Beta Blockers Action
e.g. Antenolol (most common) & propanolol.
Unclear mechanism
Reduction sympathetic drive to heart, reducing cardiac output.
Reduction in sympathetically evoked renin release.
Beta Blockers: Contraindication
May block bronchial beta-2 receptors and are
contrindicated in ASTHMA
caution in COPD.
True even for beta-1 selective agents
(they are only selective not SPECIFIC).
ACEIs - Adverse Effects (3)
Cough (10%) may be intolerable
Severe first dose hypertension
Renal damage?
Calcium Channel Blockers - Adverse Effects (3)
Peripheral Oedema
Postural hypotension
Constipation (some)
Alpha Blockers - Adverse Effects (2)
Widespread (poorly tolerated)
Postural hypotension
NB. (Also prescribed in prostate gland enlargement, relax muscles around bladder and prostate allowing urine to pass).
