Pharma - Hypertension Flashcards
List 4 common types of hypertensives.
→ ACE inhibitors
→ Calcium channel blockers
→ Thiazides or Thiazide-like diuretics
→ Angiotensin receptor blockers
List 3 examples of ACE inhibitors.
→ Ramipril
→ Lisinopril
→ Perindopril
What is the mechanism of action for ACE inhibitors?
→ Inhibit the angiotensin converting enzyme.
→ Prevent the conversion of
angiotensin I to angiotensin II by ACE.
What is the drug target for ACE inhibitors?
ACE
What are the main side effects of ACE inhibitors?
→ 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
What is a pro-drug?
drug that requires hepatic activation to generate metabolites needed to therapeutic effect
Which of the ACE inhibitors are pro-drugs?
→ ramipril
→ perindopril
What must be closely monitored when prescribing ACE inhibitors?
→ eGFR
→ serum potassium
List 2 examples of Calcium channel blockers.
→ Amlodipine
→ Felodipine
What is the mechanism of action of a calcium channel blocker?
→ 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 and prevention of cross-bridge formation
→ resultant vasodilation reduces peripheral resistance.
What is the drug target of calcium channel blockers?
→ L-type calcium channels
→ on vascular smooth muscle
What are the main side effects of Calcium channel blockers?
→ Ankle oedema
→ Constipation
→ Palpitations
→ Flushing/Headaches
Which type of calcium channel blockers demonstrate higher degree of vascular selectivity?
dihydropyridine
List 2 examples of thiazide or thiazide-like diuretics?
→ thiazide = Bendro-flumethiazide
→ thiazide-like diuretics = Indapamide
What is the mechanism of action of thiazide or TLD?
→ 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
What is the drug target + site of action for thiazide or TLD?
→ Na+ and CL- co-transporters
→ in the early DCT
What are the main side effects of thiazide or TLD?
→ Hypokalemia
→ Hyponatremia
→ Metabolic alkalosis (increased hydrogen ion excretion)
→ Hypercalcemia
→ Hyperglycemia (hyperpolarised pancreatic beta cells).
→ Hyperuricemia
What happens after 1-2 weeks of using thiazides or TLDs?
lose their diuretic effects
How do thiazides or TLDs maintain their anti-hypertensive effects after 1-2 weeks?
due to their vasodilating properties, especially for thiazide-like diuretics
List 3 examples of angiotensin receptor blockers.
→ Losartan
→ Irbesartan
→ Candesartan
What is the mechanism of action for angiotensin receptor blockers?
These agents act as insurmountable (i.e. non-competitive) antagonists at AT1 receptor (found on kidneys and on the vasculature)
What are the drug targets of ARBs?
synaptic vesicle protein SV2A
What are the main side effects of ARBs?
→ Hypotension
→ Hyperkalaemia (care with K+ supplements or K+-sparing diuretics)
→ Foetal Injury (AVOID IN PREGNANT WOMEN)
→ Renal failure (in patients with renal artery stenosis)
What’s more effective? ARBs or ACE inhibitors?
ACE inhibitors
Which ARBs are pro-drugs?
→ Losartan
→ Candesartan
