Drugs used in the treatment of hypertension Flashcards
(42 cards)
Which one of the following suffixes indicate that the drug is an ACE inhibitor?
a) -olol
b) -pril
c) -artan
d) -zosin
B
Which one of the following beta-blockers is cardio-selective?
a) Atenolol
b) Propranolol
c) Carvedilol
d) Labetalol
A
Match the drug with the appropriate statement
Drug Atenolol
Enalapril
Doxazosin
Statement
Dry cough and angioedema
Indicated for benign prostatic hyperplasia Caution advised in people with asthma and COPD
Sure, let’s match the drugs to the appropriate statements:
- Atenolol: Caution advised in people with asthma and COPD
- Enalapril: Dry cough and angioedema
- Doxazosin: Indicated for benign prostatic hyperplasia
Which one of the following drugs are more likely to be used as first-line treatment of hypertension according to EML/STG’s?
a) Atenolol
b) Doxazosin
c) Enalapril
d) Hydrochlorothiazide
c
Major risk factors for hypertension
Major risk factors for hypertension
* Levels of systolic and diastolic Bp
Smoking
* Dyslipidaemia:
* Total cholesterol > 5.1 mmol/l, OR
* LDL > 3 mmol/l, OR
* HDL men < 1 and women < 1.2 mmol/l
* Diabetes mellitus
* Men > 55 years
* Women > 65 years
* Family history of early onset of CVD:
* Men aged < 55 years
* Women aged < 65 years
* Waist circumference: abdominal obesity:
* Men ≥ 102 cm
* Women ≥ 88 cm
* The exceptions are South Asians and Chinese: men: > 90 cm and women: > 80 cm
Target organ damage (TOD)
Target organ damage (TOD):
* Left ventricular hypertrophy
* Hypertensive retinopathy
* Microalbuminuria or positive urine dipsticks for albuminuria or elevated albumin
creatinine ratio
* Elevated creatinine level (or eGFR <60ml/min)
Associated clinical conditions:
Ischaemic heart disease / MI
* Heart failure
* Stroke / transient ischemic attack(TIA)
* Chronic kidney disease
* Peripheral arterial disease
Sites of action of
the following drugs are shown
1, vasodilators; 2,
β -adrenoceptor antagonists ( β -
blockers);
3, α-adrenoceptor antagonists (α-blockers);
4, angiotensin receptor
antagonists;
5, centrally acting sympatholytics;
6, angiotensin-converting enzyme (ACE)
inhibitors;
7, direct renin inhibitors; and
8, diuretics. The vasodilators, sympatholytic
drugs, and angiotensin inhibitors reduce PVR; β -adrenoceptor blockers primarily reduce
cardiac output; and diuretics promote sodium excretion and reduce blood volume.
Antihypertensives
vasodilators: calcuim blockers and agents acting on arterial smooth muscle
diuretics
centrally acting agents
Agents acting on arteriolar smooth muscle
Hydralazine
Minoxidil
Hydralazine
Uncertain mechanism of action: relax arteries and arterioles = vasodilation =
↓peripheral resistance = ↓ BP accompanied by reflex tachycardia and ↑
CO (interferes with action of inositol triphosphate on Ca+ release from
the sarcoplasmic reticulum)
Indications: 4
th line treatment for hypertension (low doses in combination
with b-blocker), supplementary tx in chronic cardiac failure
Adverse effect: long-term use can cause immune disorder resembling SLE
Indicated for HF in patients of African origin in combination with long-acting
nitrate
Minoxidil
Direct acting vasodilator(by activating K+ channels), increases CO and
accompanied by tachycardia
Potent and long-acting vasodilator
Last line unresponsive/refractory hypertension (NOT used as
monotherapy, concurrent diuretic and b-blocker often required)
Adverse effect: marked salt and water retention (NOT for heart failure),
prescribed with a loop diuretic, hirsutism
- What are the 2 categories of calcium-channel blockers and examples?
elective CCB with mainly
vascular effects
Selective CCB with direct
cardiac effects
Loop diuretics: indications
- Oedema, pulmonary oedema
- Oedema secondary to heart failure, liver cirrhosis, etc.
- Reserved for use in hypertension for patient with poor renal function
(CrCL<30ml/min) - Despite greater natriuretic effect than thiazides, usually less effective
that thiazides to control blood pressure in patients with normal renal
function
* Hypercalcaemia
Loop diuretics: pharmacokinetics
- Route of administration: oral or IV
- Partly metabolised before excreted in the urine
Loop diuretics: adverse effects
Hypokalaemia, hypomagnesaemia, hypocalcaemia, hyponatraemia, * Hyperuricaemia (gout), hypochloraemic alkalosis
* Dehydration, hypotension, hypovolaemia
* Endocrine abnormalities like thiazides
* Hearing loss
* Hypersensitivity (sulphonamide structure)
Potassium-sparing diuretics: mechanism of action.
Sodium enters the principal cells through sodium channels. Sodium is then
transferred into the interstitial fluid by the sodium pump, while potassium is pumped in the opposite direction and then moves through potassium channels into the tubular fluid.
Aldosterone
Aldosterone stimulates these processes by increasing the synthesis of messenger RNA that encodes for sodium channel and
sodium pump proteins.
The potassium-sparing diuretics exert
The potassium-sparing diuretics exert
their effects via two mechanisms:
amiloride and triamterene inhibit the
entrance of sodium into the principal cells, whereas spironolactone blocks the mineralocorticoid (aldosterone) receptor and thereby inhibits sodium reabsorption and potassium secretion.
Where in the nephron does Spironolactone exert its effects?
a. Proximal convoluted tubule
b. Loop of Henle
c. Distal convoluted tubule and collecting duct
d. Bowman’s capsule
Spironolactone acts on the distal tubule and collecting duct by blocking aldosterone receptors.
What is the result of aldosterone receptor blockade by Spironolactone in the kidneys?
a. Increased potassium excretion
b. Increased sodium reabsorption
c. Decreased sodium reabsorption and decreased potassium excretion
d. Decreased urine output
By blocking aldosterone receptors, Spironolactone promotes sodium excretion and reduces renal potassium excretion.
How does Spironolactone affect sodium channels and the sodium pump in the kidney?
a. Enhances their activity
b. Inhibits their expression
c. Increases their synthesis
d. No effect on these proteins
pironolactone blocks the mineralocorticoid receptor, which interacts with DNA to promote the expression of genes for sodium channels and the sodium pump, leading to reduced sodium reabsorption
Which condition is Spironolactone primarily used to treat due to its mechanism of action?
a. Hypokalemia
b. Hyperkalemia
c. Hypertension
d. Hypotension
Hypertension
Rationale: Spironolactone is used to treat hypertension and conditions like heart failure by reducing sodium reabsorption and thereby lowering blood pressure.
In addition to its role in the kidney, what other effect does Spironolactone have due to its aldosterone antagonism?
a. Decreased blood glucose levels
b. Reduced cardiac fibrosis
c. Increased urine concentration
d. Enhanced muscle contraction
b. Reduced cardiac fibrosis
Rationale: By antagonizing aldosterone, Spironolactone can reduce cardiac fibrosis, which is beneficial in conditions like heart failure.