Hypertension Drugs Flashcards
BP=
Cardiac output x total peripheral resistance
We can reduce cardiac output by…
Reducing
Heart rate
Stroke volume
Plasma volume
Reduce total peripheral resistance by…
Dilating arterioles
Diuretics work by
Vasodilator a work by
B blockers work by
ACE inhibitors work by
A blockers work by
Angiotensin antagonists work by
Reducing plasma volume then gradually TPR
Briefly lowering TPR Reduce cardiac output and kidney renin secretion Inhibit vasoconstrictor production Inhibit noradrenaline action on TPR Inhibit angiotensin action on TPR
Action of diuretics
Increase sodium exertion
Water loss follows
Reduce plasma volume
Reduce CO
Thiazides diuretics
Potent
Reduce systolic and diastolic BP
Inhibit NA+ and CL- in distal tubule
Increase renin release
Chlorothiazide
Thiazides diuretic
Distal tubule inhibits sodium chloride
Hydrochlorothiazide
Thiazides diuretic
Distal tubule sodium chloride
Bendrothiazide
Thiazide diuretic
Distal tubule
Chlorthalidone
Metolazone
Thiazides like structured thiazides
Thiazides SE
More frequent urination
High safety
When to treat hypertension (parameters)
Systolic BP of more than or equal to 160
Diastolic of more than or equal to 100
Patients with CV disease diabetes or organ damage
Systolic 140-159
Diastolic 90-99
Loop diuretics
Very potent
No more effective that thiazides
Reserved for use in those with renal insufficiency resist and hypertension or heart failure
Vasodilators work to
Act directly on the smooth muscle or arteries and arterioles
Lower intracellular calcium concentration
Muscle cell relaxation
Vasodilation
Calcium antagonists work by
Blocking calcium entry through voltage operated calcium channels in arterial smooth muscle cells
Dihydropyridines
Highly effective calcium antagonists affecting most smooth muscle
Nifedipine
Amlodipine
Nicardipine
Calcium antagonists
Benzothiazepine
Calcium antagonists working also in conduction tissue of heart
Diltiazem
Calcium antagonist
Slows heart rate
Potentiates beta blocker action
Calcium antagonists SE
All:
Flushing
Ankle odema
Diltiazem;
Cardiac depression
Beta blocker interaction
Alpha blockers work by
Selectively blocking a1 adrenoreceptors
Prevent vasoconstriction action of noradrenaline
Doxazosin
Terazosin
Prazosin
Alpha blockers
SE of a blockers
Postural hypotension
Generally well tolerated
Beta blockers work by
Binding to b1 adrenoreceptors in the heart
sA node and ventricular muscle
Block action of noradrenaline
Reduce rate and force of heart initially
TPR reset at lower level
SE of beta blockers
Cold hands
Fatigue
Asthma attack
Heart failure
Conduction block
Blood lipids
ACE inhibitor works by
Preventing the conversion of angio 1 to angio 2
This is a potent vasoconstrictor that stimulated aldosterone secretion inhibiting the excretion of salt and water.
Cause vasodilation
Reduced plasma volume
Catopril
Enalapril
Ramipril
Lisinopril
ACE inhibitors
SE of ACE inhibitors
Dry cough
Hypotension
Explain the renin angiotensin system
Angiotensinogen secreted from the liver
Renin secreted from the kidney converts it to angio I
ACE from lungs converts to angio II
Vasoconstriction and aldosterone secretion from kidney
Angiotensin II receptor antagonists work by
Blocking the action of angio II at its receptors
Losartan
Candesartan
Eprosartan
Valsartan
Angio II receptor antagonists
