Hypertension

Question 1

Drugs

Answer 1

Angiotensin converting enzyme inhibitors
Examples:
Ramipril
Lisinopril
Perindopril

Calcium channel blockers
Examples:
Amlodipine
Felodipine

Thiazide or thiazide-like diuretics
Examples:
Bendro-flumethiazide (thiazide)
Indapamide (thiazide-like)

Angiotensin receptor blockers
Examples:
Losartan
Irbesartan
Candesartan

Question 2

Angiotensin converting enzyme inhibitors action

Answer 2

Inhibit the angiotensin converting enzyme.

Prevent the conversion of angiotensin I to angiotensin II by ACE.

Question 3

ACEi target

Answer 3

ACE

Question 4

ACEi side effects

Answer 4

Cough
Hypotension
Hyperkalaemia (care with K+ supplements or K+-sparing diuretics)
Foetal Injury (AVOID IN PREGNANT WOMEN)
Renal failure (in patients with renal artery stenosis)-
Urticaria/Angioedema

Question 5

ACEi other

Answer 5

Most ACE inhibitors (not lisinopril) are pro-drugs. They require hepatic activation to generate the active metabolites required for therapeutic effects.

eGFR and serum potassium must be regularly monitored when prescribing ACE inhibitors.

In 2020, ramipril was the 7th, lisinopril the 42nd and perindopril the 51st most commonly prescribed drugs in the West London area

Question 6

Calcium channel blocker action

Answer 6

Block L-type calcium channels – predominantly on vascular smooth muscle. This results in a decrease in calcium influx, with downstream inhibition of myosin light chain kinase and prevention of cross-bridge formation. The resultant vasodilation reduces peripheral resistance.

Question 7

Calcium channel blocker target

Answer 7

L-type calcium channel

Question 8

Calcium channel blocker side effects

Answer 8

Ankle oedema
Constipation
Palpitations
Flushing/Headaches

Question 9

Calcium channel blocker other

Answer 9

Dihydropyridine type calcium channel blockers demonstrate a higher degree of vascular selectivity

In 2020, amlodipine was the 2nd and felodipine the 98th most commonly prescribed drugs in the West London area

Question 10

Thiazide action

Answer 10

They block the Na+, Cl- co-transporter in the early DCT.
Therefore Na+ and Cl- reabsorption is inhibited.
As a result the osmolarity of the tubular fluid increases, decreasing the osmotic gradient for water reabsorption in the collecting duct.

Question 11

Thiazide target

Answer 11

Sodium/chloride cotransporter

Question 12

Thiazide side effects

Answer 12

Hypokalemia
Hyponatremia.
Metabolic alkalosis (increased hydrogen ion excretion)
Hypercalcemia.
Hyperglycemia (hyperpolarised pancreatic beta cells).
Hyperuricemia.

Question 13

Thiazide other

Answer 13

Thiazide and thiazide-like diuretics both lose their diuretic effects within 1-2 weeks of treatment. Continuing anti-hypertensive action appears to be due to vasodilating properties (these are more pronounced for the thiazide-like diuretics)

In 2020, bendro-flumethiazide was the 38th and indapamide the 46th most commonly prescribed drugs in the West London area

Question 14

Angiotensin receptor blocker action

Answer 14

These agents act as insurmountable (i.e. non-competitive) antagonists at AT1 receptor (found on kidneys and on the vasculature)

Question 15

Angiotensin receptor blocker target

Answer 15

Angiotensin receptor

Question 16

Angiotensin receptor blocker side effects

Answer 16

Hypotension

Hyperkalaemia (care with K+ supplements or K+-sparing diuretics)

Foetal Injury (AVOID IN PREGNANT WOMEN)

Renal failure (in patients with renal artery stenosis)-

Question 17

Angiotensin receptor blockers other

Answer 17

Most trials indicate that angiotensin receptor blockers are not as effective anti-hypertensive agents as ACE inhibitors.

Losartan and candesartan are pro-drugs. They require hepatic activation to generate the active metabolites required for therapeutic effects.

In 2020, losartan was the 13th, irbesartan the 57th and candesartan the 80th most commonly prescribed drugs in the West London area