Drugs used in the treatment of hypertension

Question 1

Describe how arteries are pressure reservoirs

Answer 1

Contraction- aorta and arteries expand and store pressure in elastic walls (stretch), semilunar valve opens so blood ejected from ventricles flows into arteries, ventricles contract
Relaxation- elastic recoil in arteries maintain driving pressure during ventricular diastole

Question 2

Why are stiff arteries bad?

Answer 2

Wider pulse pressure so cause a higher systolic BP leading to higher stroke and coronary risk/ cause a lower diastole BP reducing coronary artery filling

Question 3

What is normal systolic blood pressure?

Answer 3

up to 120
Bad= 130-150
Severe= 160+

Question 4

What are the complications of inadequately controlled hypertension/ high BP?

Answer 4

Cardiac= heart attack, angina pectoris, cardiac failure
Cerebrovascular= stroke, transient cerebral ischaemia, multi-infarct dementia
Vascular= peripheral vascular disease, aortic aneurysm/rupture
Other= renal damage, retinopathy/papilloedema

Question 5

What are the statistics for Scotland?

Answer 5

30% of adults in Scotland have high blood pressure
Only 27% have it treated and controlled
1.2 million appointments for high blood pressure

Question 6

How do genes relate to high blood pressure?

Answer 6

30-50% genetic heritability, mostly found in the kidney

Question 7

What is critical for high blood pressure?

Answer 7

Salt handling in the kidney

Question 8

Population approaches to reducing blood pressure

Answer 8

Increase exercise, increase potassium and nitrate intake (fruit and veg)
Reduce sodium/ alcohol/ calorie/ saturated fat intake (if excessive), reduce/ quit smoking

Question 9

What is hypertension?

Answer 9

Hypertension is having a blood pressure at which treatment does more good than harm
Affects 1 in 3 adults in UK, leading cause of cardiovascular morbidity and mortality worldwide

Question 10

Who is best to prioritise treatment for?

Answer 10

Older people (50+)
People with diabetes
People with other CVS risk factors (lipids, smoking)

Question 11

How is hypertension assessed?

Answer 11

Blood pressure- home or ambulatory
ECG- arrhythmia, AMI
Electrolytes- low sodium or potassium
Creatinine/ eGFR- renal function
Urate- gout
Glucose/ HbA1c- diabetes
Lipid profile- hypocholesteraemia
Urinalysis- protein, glucose, blood

Question 12

Drug treatment of hypertension

Answer 12

ACE inhibitor/ ANG11 receptor blocker
Beta- adrenoreceptor blocker (x)
Calcium entry blocker
Diuretic (thiazide-type)

Question 13

Examples of hypertension drugs

Answer 13

Alpha adrenoreceptor blocker= doxazosin
Beta blocker= bisoprolol
Potassium channel openers= minoxidil
Loop diuretics= furosemide/ torasemide
Mineralocorticoid antagonists= spironolactone/ eplerenone

Question 14

Are the drugs prescribed different for different ethnicities?

Answer 14

Younger, Eurasian= A or B

Older, Afro-Caribbean= C or D

Question 15

What is the current treatment algorithm?

Answer 15

A/ C or D
A+C or A+D
A+C+D
Specialist review

Question 16

What are the benefits of hypertension treatments?

Answer 16

ACE inhibitors have particular benefits post-MI, Heart failure, Diabetic nephropathy
Beta-blockers improve outcomes in IHD
Calcium antagonists reduce symptoms in angina and isolated systolic hypertension
Diuretics (thiazide-like) have benefits in heart failure

Question 17

What are common agents for each hypertension drug?

Answer 17

ACE inhibitors- enalapril, lisinopril, Ramipril
ANG-11 receptor blockers- losartan, candesartan
Beta-blockers- atenolol, metoprolol, bisoprolol
Calcium antagonists- nifedipine, amlodipine
Diuretics- Bendroflumethiazide, chlortalidone/ indapamide

Question 18

What is the mechanism of ACE inhibitor action?

Answer 18

Inhibit ACE, block RAAS, increase BK, dilate arteries (and veins)

Question 19

What is the mechanism of beta-blocker action?

Answer 19

Blocks beta-adrenoreceptors, reduce cardiac rate and output, block RAAS, initial vasoconstriction (ultimately vasodilate)
Calcium antagonists- block voltage-operated calcium channels, dilate arteries (+/- hear rate reduction)
Thiazides- inhibit Na+/Cl- symport, distal tubular natriuresis, dilate arteries and veins

Question 20

What are the side effects of treatment?

Answer 20

ACE inhibitors= cough, renal dysfunction
Angiotensin receptor blockers= few
Beta blockers= wheeze, cold peripheries, lassitude, exercise intolerance, bad dreams, impotence, heart block, diabetes
Calcium antagonists- headaches, flushing, ankle swelling, tachycardia
Diuretics- impotence, rashes, biochemical- low Na, low K, high glucose (risk of diabetes), high urate (risk of gout)

Question 21

What are the reasons for treatment failure?

Answer 21

Poor adherence (extremely common)
Ineffective combinations (common)
Other drugs (NSAIDs, common)
Inappropriately low doses (common)
Secondary causes (uncommon, less than 5%)

Question 22

Secondary causes of hypertension (medicines)

Answer 22

Oestrogen oral contraceptives
Liquorice/ carbenoxolone/ steroids
Non-steroidal anti-inflammatoroes (NSAIDs)
Sympathomimetics, including cocaine
Alcohol
Erythropoetin
Cyclosporine A

Question 23

Secondary causes of hypertension (renal/ vascular)

Answer 23

Renal artery stenosis (atheroma/ fibromuscular)
Glomerulonephritis/ pyelonephritis/ vasculitis
Obstructive uropathy
Polycystic kidney disease
Coarctation of the aorta

Question 24

Secondary causes of hypertension (endocrine)

Answer 24

Glucocorticoid-related (Cushing’s syndrome)
Mineralocorticoid-related (Conn’s syndrome)
Pheochromocytoma
Pre-eclampsia
Rarer genetic causes- (17betaHSD, 11betaHSD, Liddle’s, Gordon’s syndrome)

Question 25

What are the roles of specialists in hypertension?

Answer 25

• Investigate underlying causes (renal and endocrine investigations)
• Ambulatory BP monitoring
• Advice on complex cases
• Admit for drug challenge/ drug screening
• Hypertension research