Hypertension Flashcards
What is the drug target for ACE Inhibitors?
Angiotensin converting enzyme
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 are the 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
Why are ACE inhibitors considered pro drugs?
They require hepatic activation to generate the active metabolites required for therapeutic effects.
What must be regularly monitored when prescribing ACE inhibitors?
eGFR and serum potassium must be regularly monitored when prescribing ACE inhibitors.
What are some examples of ACE inhibitors?
Ramipril
Lisinopril
Perindopril
What are some examples of calcium channel blockers?
Amlodipine
Felodipine
What are the side effects of CCB?
Ankle oedema
Constipation
Palpitations
Flushing/Headaches
What is the mechanism of action of CCBs?
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.
What is the drug target of CCBs?
L-type calcium channel
Which type of CCBs demonstrate a higher degree of vascular selectivity?
Dihydropyridine type calcium channel blockers demonstrate a higher degree of vascular selectivity
What is the mechanism of action of Thiazide?
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 site of action for Thiazide?
Sodium/chloride
co-transporter
What is the mechanism of action of 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 side effects of Angiotensin-receptor blockers?
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 are some examples of angiotensin receptor blockers?
Losartan
Irbesartan
Candesartan
What is the clearance of a drug?
Clearance is the measure of the ability of the body to eliminate a drug. Clearance by means of various organs of elimination is additive. Elimination of drug may occur as a result of processes that occur in the liver, kidney, and other organs.
What is the elimination half life of a drug?
Elimination half-life is the length of time required for the concentration of a particular drug to decreasetohalf of itsstarting dose in the body.
What is the time to peak plasma levels?
Time to peak concentration is the time required for a drug to reach peak concentration in plasma. The faster the absorption rate, the lower is the time to peak plasma concentration.
Who are ARB’s for?
ARBs for patients of African or Caribbean descent
Why are ACEi used ahead of ARB’s?
ACE inhibitors are typically used ahead of angiotensin 2 receptor blockers (partly due to cost/partly due to evidence that ACE Is are more effective).
What are the effects of Thiazide-like diuretics?
Decrease blood volume
Decrease venous return
Decrease cardiac output
how long do the diuretic effects?
The diuretic effect of thiazides only lasts for 1-2 weeks. - The kidney becomes tolerant to the diuretics because there is a rebound activation of the renin angiotensin system which counteracts the diuretic effect due to increasing sodium reabsorption.
