Antihypertensive pharmacology Flashcards
List the features of grade 1 hypertensive retinopathy
Increased tortuosity and reflectiveness of retinal arteries (copper/silver wiring)
List the features of grade 2 hypertensive retinopathy
Increased tortuosity and reflectiveness of retinal arteries (copper/silver wiring)
PLUS
AV nicking
List the features of grade 3 hypertensive retinopathy
Increased tortuosity and reflectiveness of retinal arteries (copper/silver wiring)
PLUS
AV nicking
PLUS
hemorrhages and soft (cotton wool) exudates
List the features of grade 4 hypertensive retinopathy
Increased tortuosity and reflectiveness of retinal arteries (copper/silver wiring)
PLUS
AV nicking
PLUS
hemorrhages and soft (cotton will) exudates
PLUS
papilloedema
Name the blood tests and investigations that should be performed for hypertensive patients
FBC, U&E’s, TFT’s, fasting lipids, glucose
ECG
CXR
24 hour BP monitor
Echo
NICE guidelines treatment target BP for people < 80 years old (non-diabetic)
<140/90 mmHG
NICE guidelines treatment target BP for people > 80 years old (non-diabetic)
<150/90 mmHg
NICE guidelines treatment target BP for diabetics
<135/85 mmHg
Name some of the conservative/lifestyle factors for managing HTN
- Follow a healthy diet
- Exercise regularly
- Reduce dietary salt intake
- Reduce caffeine consumption
- Stop smoking
- Reduce alcohol consumption
Step 1 antihypertensive treatment in someone (non-Afro-Carribbean) < 55 years old and/or diabetic?
A =
Ace Inhibitors (Ramipril, Lisinopril, Enalapril)
ARBs (Candesartan, Losartan)
Step 1 antihypertensive treatment in a person > 55 years old or of Afro-Caribbean family origin?
C =
CCB (Amlodipine, Diltiazem, Verapamil)
Step 2 antihypertensive treatment in a person < 55 years old
Ace inhibitor or ARB + CCB or thiazide diuretic
NICE guidance treatment targets
Diabetes: <135/85 mmHg
Age < 80 years: <140/90 mmHg
Age > 80 years: <150/90 mmHg
NICE guidance treatment targets
Step 3 antihypertensive treatment for everyone
Ace inhibitor or ARB +
CCB +
Thiazide-like diuretic
Drug class of Amlodipine?
Dihydropyridine (calcium channel blocker). This type of CCB is relatively selective for vasculature.
Indications: First or second line treatment of HTN in patients 55 years or older or Afro-Carribean. Reduces risk of stroke, MI, and death from CVD.
Amlodipine
Mechanism of action: Blocks the L-type voltage-gated calcium channel, decreasing intracellular calcium levels. This causes relaxation and vasodilation in arterial smooth muscle. Decreases force of contraction in cardiac muscle
Calcium channel blockers
Which of the CCB’s is most negatively inotropic, acting to reduce cardiac contractility and reduce the heart rate (most “cardioselective” of the CCB’s)
Verapamil
Which anti-hypertensive drug is renowned for causing ankle swelling?
Amlodipine (via preferential dilation of pre-capillary arteriole leading to increased hydrostatic pressure)
Side effects of this class of anti-hypertensives include palpitations (reflex tachycardia), constipation, flushing, HA, and exacerbation of heart failure -D&V-
Calcium channel blockers
Mechanism of action of ace-inhibitors?
Inhibit angiotensin-converting enzyme (ACE), reducing conversion of angiotensin I to angiotensin II. Blocking the action of Angiotensin II reduces peripheral vascular resistance (afterload) which lowers BP.
Important side effects of ace-inihibitors? (3)
- Dry cough d/t bradykinin accumulation in lungs
- HYPERkalaemia- lower aldosterone level promotes potassium retention
- Renal impairment/failure- Especially with renal artery stenosis.
Losartan belongs to which drug class?
ARB’s or angiotensin II receptor antagonist
Mechanism of action of Losartan?
Blocks action of angiotensin II on the AT1 receptor. Has similar physiological effects to Ace-inhibitors.
First and most commonly used ARB in hypertension?
Losartan
First line drug in hyperaldosteronism?
Spironolactone (aldosterone antagonist)
MOA of Spironolactone?
Blocks the upregulation of Na+ channels in the DCT by aldosterone
What are the RENAL secondary causes of HTN?
Glomerulonephritis, diabetic nephropathy, renal artery stenosis, and pyelonephritis
What are some ENDOCRINE secondary causes of HTN?
Cushing’s syndrome, Conn’s syndrome, steroid therapy, pheochromocytoma
Treatment recommendations:
Stage 1: BP >140/90 (Treat if end organ damage or diabetic)
Stage 2: BP >160/100 (Treat once confirmed on 24hr BP)
Stage 3: SBP > 180 (Treat immediately)
:)
Side effects of calcium channel blockers?
Palpitations (reflex tachycardia)
Constipation
Flushing
Headache
Exacerbation of heart failure (D&V)
Side effects of Spironolactone?
Gynaecomastia
Hyperkalaemia
Impaired renal function
Which of the anti-hypertensive drugs acts to block the Na/Cl symporter in the distal convoluted tubule?
Thiazide diuretics (Bendroflumethiazide)
Which antihypertensive drug activates ATP-sensitive potassium channels in smooth muscle of blood vessels to dilate arterioles?
Indapamide (“Thiazide-like” diuretic)
Side effects of this drug class include:
(Kidney)
HYPOnatraemia
HYPOmagnesaemia
HYPOkalaemia
Alkalosis
HYPERcalcaemia
Increase in urate (Gout)
Increase in glucose –> diabetes, insulin resistance
?Liver
Increase in lipids –> arterial disease
Thiazide diuretics
Which anti-hypertensive drug class is contraindicated in diabetics with recurrent hypoglycaemia?
Beta blockers (eg Bisoprolol) as they can mask sx of hypoglycaemia
MOA: Blocks Alpha-1 receptors, decreasing intra-cellular calcium release in arteriolar smooth muscle
Alpha blockers (eg Doxazosin)
Side effects of Doxazosin?
Palpitations (reflex tachycardia) and psotural hypotension
An assessment tool used to help determine which patients are most at risk of having a stroke or heart attack in the next 10 years
QRISK2 score
A moderate QRISK2 score of 10-20% means that a patient has between a ____-_____% chance of having a stroke or heart attack in the next 10 years
10-20%
Drug class of Bumetanide?
Loop diuretic
This drug class acts primarily on the ascending limb of the loop of Henle, where they inhibit the Na/K/2Cl transporter. This protein is responsible for transporting Na, Cl-, and K+ from the tubular lumen into the epithelial cells
Loop diuretics (eg Furosemide, Bumetanide)
Side effects of loop diuretics?
Dehyrdation
Hypotension
Electrolyte losses: Na+, Cl-, and K+ (as well as Mg, Ca and H+ ions indirectly)
Which drug is the “potassium sparing” diuretic?
Spironolactone
Side effects of ARB’s (Losartan, Candesartan)?
Hypotension (particularly after the first dose)
Hyperkalaemia
Renal failure
This potent, direct-acting vasodilator breaks down in circulation to release nitric oxide. It can be used in cases of accelerated or malignant HTN
sodium nitroprusside
These drugs can be used IV in hypertensive emergencies (although other agents such as labetalol or sodium nitroprusside, are preferred)
Nitrates
Short-acting- Glyceryl trinitrate
Long-acting- Isosorbide mononitrate
