Hypertension Flashcards
Define Hypertension
A blood pressure which is associated with significant cardiovascular risk
What is the cause of essential (primary) hypertension?
Unknown, may be multifactorial
What is the cause of secondary hypertension?
Renal disease Renovascular disease Conn's syndrome Cushing's syndrome Hyperthyroidism Phaechromoycytoma Pregnancy Drugs
How do ACEIs work?
ACE Inhibitors inhibit Angiotensin Converting Enzyme
Prevents AI-AII
AII causes vasoconstriction/converted to aldosterone
Reduced aldosterone = reduced salt/water retention
Give several named examples of ACEIs
Ramipril Lisinopril Enalapril Captopril Perindopril
What are the main side effects of ACEIs?
Cough (potentiated bradykinin) Increase K+ Angioedema Worsening of renal function Severe first dose hypotension
When should ACEIs be avoided, and why?
Renovascular disease
Renin-dependent hypertension, ACEIs lead to renal underperfusion and SEVERE HYPOTENSION
When should ACEIs be given preferentially, and why?
In patients with diabetes - Prevention of nephropathy
What should be monitored before/during treatment with ACEIs?
Creatinine levels - indicator of renal function
What are ATRAs/ARBs?
AT1 receptor antagonists
How do ATRAs/ARBs work?
Block the action of AII at AT1 receptors
Similar effect to ACEIs but no cough
What are the two main classes of clinical vasodilators?
Calcium Channel Blockers
Alpha-Blockers
How do Calcium Channel Blockers work?
Inhibit voltage operated calcium channels on vascular smooth muscle
Vasodilation and reduced BP
Give several named examples of Calcium Channel Blockers
Diltiazem
Verapamil
Dihydropyridines (Amlodipine, Nifedipine, Felodipine)
How do dihydropyridines differ from Verapamil?
Verapamil exerts most of its effects on the heart
Dihydropyridines exerts most of their effects on arteriole smooth muscle
How do Alpha-Blockers work?
Competitive receptor antagonists of a1-adrenoceptors
Why are Alpha-Blockers last choice antihypertensives?
Widespread side effects make them poorly tolerated
ie. postural hypotension
How do Thiazides/Thiazide-like diuretics work?
Inhibit Na+/Cl- in the DCT
Reduce circulating volume AND cause vasodilatation
Give several named examples of Thiazides/Thiazide-like diuretics
Thiazide-like (Chlortalidone, Indapamide)
Thiazides (Bendroflumethiazide)
When are Thiazides/Thiazide-like diuretics ineffective, and what is the exception to this?
Moderate renal impairment
Metolazone
What are the main side effects of Thiazides/Thiazide-like diuretics?
Hypokalaemia Postural hypotension Impaired glucose control (diabetogenic) Urination Altered lipid profile Impotence?
When should Thiazides/Thiazide-like diuretics never be used?
Patients suffering from Gout
What should be monitored before and during treatment with Thiazides/Thiazide-like diuretics?
Creatinine - indicator of renal function
How do Beta-Blockers work?
MoA unclear
Reduce sympathetic drive to the heart, reducing CO
Reduce sympathetically evoked renin release
What are the main side effects of, and contraindications for, Beta-Blockers?
May block bronchial B2 receptors
Contraindicated in asthma, cause bronchospasm
Caution in COPD
Reduce hypoglycaemic awareness
Give named examples of Beta-Blockers
Atenolol
Propranolol
What are the main side effects of Calcium Channel Blockers?
Peripheral oedema
Postural hypotension
Constipation (some)
What are the key lifestyle changes that should be made when first treating hypertension?
Reduce alcohol consumption Weight reduction Reduce excess caffeine Reduce fat/salt intake Increase fruit/oily fish in the diet Increase exercise Stop smoking
How, and when, should hypertension be confirmed?
After implementation of lifestyle changes
~14 ambulatory measurements
Home devices, both arms
Describe the staging for hypertension
Stage 1 - <140/>90
Stage 2 - >160/>100
Severe - >180/110
Which patients should be treated with antihypertensive medication?
Stage 1 patients with one or more: End organ damage Diabetes CV disease/high risk CV risk All Stage 2 patients
What are the compelling indications for ACEIs/ATRAs?
Heart failure
LV hypertrophy
Diabetic nephropathy
What are the contraindications for ACEIs/ATRAs?
Renovascular disease
What are the compelling indications for Calcium Channel Blockers?
Afro-Caribbean ethnicity
DHPs in isolated systolic HT
Diltiazem/Verapamil in angina
What Calcium Channel Blockers are contraindicated in CHF?
Diltiazem
Verapamil
What are the compelling indications for Thiazides/Thiazide-like diuretics?
Elderly
What are the contraindications for Thiazides/Thiazide-like diuretics?
Gout
What are the compelling indications for Beta-Blockers?
Myocardial Infraction
IHD
CHF
What are the contraindications for Beta-Blockers?
Asthma/COPD
Heart block
What are the compelling indications for Alpha-Blockers?
Resistance to other drugs
Prostatic hypertrophy
What is the first stage of treatment for <55/non-black/high renin patients?
ACEIs/ATRAs
What is the first stage of treatment for >55/black/low renin patients?
Calcium Channel Blockers
What is the second stage of treatment in all patients?
ACEIs/ATRAs + Calcium Channel Blockers
What is the third stage of treatment in all patients?
ACEIs/ATRAs + Calcium Channel Blockers + Diuretic
What drugs can be added in stage four of treatment (resistance)?
Alpha Blocker
Spironolactone
Diuretic
Beta-Blocker
When should the use of statins be considered?
All patients at high risk of CVD, even with ‘normal’ cholesterol
