Pharmacology of Hypertension - Core Drugs & Case Study Flashcards
What are the 4 core drug classes involved in the treatment of hypertension?
- Angiotensin converting enzyme (ACE) inhibitors
- Calcium channel blockers
- Thiazide or thiazide-like diuretics
- Angiotensin receptor blockers (ARBs)
What class of drugs have the suffix -pril?
ACE inhibitors
Ramipril is an example of what drug class used in the treatment of hypertension?
ACE inhibitors
Lisinopril is an example of what drug class used in the treatment of hypertension?
ACE inhibitors
Perindopril is an example of what drug class used in the treatment of hypertension?
ACE inhibitors
What is the suffix for ACE inhibitors?
-pril
What is the primary mechanism of action of ACE inhibitors?
Inhibit the angiotensin converting enzyme
Prevent conversion of angiotensin I to angiotensin II
- Reduced vasoconstriction
- Inhibits aldosterone which usually promotes sodium reabsorption and potassium excretion
- Increased sodium reabsorption —> water retention —> increased blood volume and contributes to increased blood pressure
What is the function of angiotensin II?
Main effector molecule of the RAS
- Increases BP
- Vasoconstriction
- Influences renal tubuli to retain sodium + water
- Stimulates aldosterone release from adrenal gland
- Sympathetic nervous stimulation
What are the main side effects of ACE inhibitors?
Cough
Hypotension
Hyperkalaemia (care with K+ supplements or K+-sparing diuretics)
Foetal injury
Renal failure
Urticaria/Angioedema
Why should the use of ACE inhibitors be avoided in pregnant women?
Foetal injury is a side effect of ACE inhibitor use
What side effect do patients on ACE inhibitors who have renal artery stenosis risk having?
Renal failure
Most ACE inhibitors are pro-drugs. What do they require to be activated?
Require hepatic activation to generate the active metabolites required for therapeutic effects
Most ACE inhibitors require hepatic activation to generate the active metabolites required for therapeutic effects.
What kind of drugs are they?
Pro-drugs (sans lisinopril)
What must be monitored regularly when prescribing ACE inhibitors?
eGFR & serum potassium
What class of drugs have the suffix -pine?
Calcium channel blockers
Dihydropyridine calcium antagonists
What class of drugs have the suffix -dipine?
Calcium channel blockers
Amlodipine is an example of what drug class used in the treatment of hypertension?
Calcium channel blockers
Felodipine is an example of what drug class used in the treatment of hypertension?
Calcium channel blockers
What is the suffix for calcium channel blockers?
-dipine
What is the primary mechanism of action of calcium channel blockers?
Block L-type calcium channels - predominantly on vascular smooth muscle
Results in a decrease in calcium influx, with downstream inhibition of myosin light chain kinase
Also prevents cross-bridge formation
Resultant vasodilation —-> reduces peripheral resistance
What is the drug target for calcium channel blockers?
L-type calcium channel
What are the main side effects of taking calcium channel blockers?
Ankle oedema
Constipation
Palpitations
Flushing/headaches
How is selectivity different for dihydropyridine type calcium channel blockers?
Dihydropyridine type calcium channel blockers demonstrate a higher degree of vascular selectivity
What class of drugs have the suffix -mide or -zide?
Diuretics
Bendro-flu-methiazide is an example of drug class used in the treatment of hypertension?
Thiazide