Treating Hypertension Flashcards
Complications of hypertension
Haemorrhage, stroke cognitive decline Retinopathy Peripheral vascular disease Renal failure LVF, CHD, CHF, MI
Framingham study
Increasing blood pressure is associated with a progressive increase in the risk of stroke and cardiovascular disease. The rise is exponential and also age is significant
Optimal blood pressure
<120/<80
Stage 1 hypertension
Clinic blood pressure is 140/90 or higher while ABPM daytime average is 135/85 or higher
Stage 2 hypertension
Clinic BP 160/100
ABPM daytime average 150/95 or higher
Severe hypertension
Clinic systolic >180 or diastolic <110
5-10% is secondary hypertension, what are some causes
Chronic renal disease(20%, chronic pyelonephritis, polycystic kidneys, fibromuscular dysplasia)
Renal artery stenosis
Endocrine disease (Cushing’s, Conn’s)
Drug induced (NSAIDs, oral contraceptives, corticosteroids)
Pregnancy (pre-eclampsia)
Vascular (coarctation of aorta)
Sleep apnoea
Factors that increase risk of mortality from hypertension
Cigarette smoking Diabetes mellitus Renal disease Male Hyperlipidemia Previous MI or stroke Left ventricular hypertrophy
Aetiology of hypertension
Polygenic and polyfactorial
Age and hypertension and treatment for the elderly
Rises with age but should be treated aggressively in elderly as reduces MI.
But, drugs are bad in elderly w
Genetics and hypertension
Over 30 genes are recognised but they have only a small effect
Closest correlation is between siblings, possibly environment in families
Reducing salt intake
Good in hypertensive adults but no effect on normotensives
Average fall in those who reduce alcohol intake
3/5mmHg
Weight and hypertension
Up to 30% is just weight
A weight loss of 9kg in untreated patients can produce a fall of 118mmHg
In treated then 30/21 has been reported
Birth weight and hypertension
The lower the birth weight the higher the likelihood of hypertension
Race and hypertension
Black populations are genetically selected to be salt retainers so are more sensitive to high salt and also respond more to stress
Conditions to assess risk in treating hypertension
Previous MI, smoking, diabetes mellitus, hypercholesterolemia, family history, physical examination
End organ damage (do ECG, proteinuria, renal US)
When should hypertension treatment be started
An overall CVD of 20% in 10 years
What does BHS suggest the target BP should be
<135/80/85mmHg
Main reasons for treating hypertension
Reducing cerebrovascular disease by 40-50% and MI by 16-30%
What drug is used more in young people
ACE inhibitors (or ARB)
Which drugs are used more in older people with less renin
Calcium channel blockers
Thiazide type diuretics
When to offer type 1 hypertension therapy
People under 80 years old with >135/85 and Target organ damage Established CVD Renal disease Diabetes A ten year CB risk>20% in 10 years
stage 2 hypertension
ABPM >150/95
Always treat
People aged under 40 with hypertension
Seek specialist help for secondary causes or organ damage
Blood pressure target in over 80s
145/85 instead of 135/80-85
Step 1 treatment for people aged over 55 and black/Caribbean people and pregnant/ child bearing age women
Calcium channel blockers
If not suitable (oedema or intolerance or heart failure)
Thiazide like diuretic
Step one treatment for under 55s
ACE inhibitors/ARB
except for afro-caribbeans or women of childbearing age
Step 2 treatment
Add thiazide type diuretic eg clortalidone or idapamide
Step 3
Combine CCB, ACEI, diuretic
Step 4
Resistant hypertension.
Consider further diuretic therapy with low dose spironolactone (25mg/day) if blood K is under 4.5mmol/l
If not give higher thiazide like diuretic
Angiotensin converting enzyme inhibitors (ACEI) and example
RAMIPRIL
competitively inhibits the actions of angiotensin converting enzyme
Contradiction to giving ACE1, pregnancy/ child bearing age
Renal artery stenosis, failure, hyperkalemia
Adverse drug reactions to ACEI
Cough, first dose hypotension, taste disturbance, renal impairment
Drug drug interactions with ACEI
NSAIDS (acute renal failure)
Potassium supplements
Potassium sparing diuretics (hyperkalemia)
Angiotensin 2 antagonists (ARB)
Eg losartan, valsartan
Competitively block angiotensin 2 T AT1 receptor
Don’t give cough like ACEI
Calcium channel blockers
Eg amlodipine/felodipine (vasodilators)
Verapimil/diltiazem (rate limiting)
Work by blocking L type cc
Relaxing arteries to reduce peripheral resistance
Reducing CO
For over 55s and women who could get pregnant
Contraindications for CCB
Acute Mi
Heart failure, bradycardia (only rate limiting)
Adverse drug reactions for CCBs
Flushing
Headache
Ankle oedema
Indigestion and reflux oesophagitis
Thiazide type diuretics
Eg idapamide, clortalidone
Used for black people
Can be used in combination and lowers strike and MI
Urinary excretion of sodium, may take weeks
Adverse drug reactions for TTD (thiazide type diuretic)
Uncommon but gout and impotence
Alpha adrenoceptor antagonists
Doxazosin blocks post synaptic. Opposes vascular smooth muscle contraction in arteries
Can cause first dose hypotension, dizziness, dry mouth, headache
Methyldopa
Used mainly in pregnancy
Acts on CNS adrenoceptors to decrease central sympathetic outflow
Sedation and drowsiness and nasal congestion and dry mouth
Pre-eclampsia
Severe BP rise from 20 weeks to >140/90 and proteinuria>300mg/24hr
