Anti-HTN Drugs Flashcards
Diuretics
- MOA
- Types
- SE
MOA: inhibit Na reabsorption –>natriuresis and diuresis. May also have direct vasodilatory effect
Types: thiazides (e.g. hydrochlorothiazide), loop diuretics (e.g. furosemide), K+ sparing (e.g. spironolactone)
SE: hypokalemia
3 actions of ATII
Aldosterone secretion
NaCl reabsorption
Vasoconstriction
RAS schematic
B1–>renin cleaves angiotensinogen–>ATI
In lung: ATI–>ATII via ACE, which also inactivates bradykinin
ATII causes:
- aldosterone secretion
- vasoconstriction
- NaCl reabs.
ACE inhibitors
- prototype
- actions
- use in diabetics?
- SE
Prototype: captoPRIL
Actions: inhibit vasoconstriction/aldosterone secretion/NaCl reabs, inc vasodilation via bradykinin build-up
Diabetics: may delay diabetic nephropathy in addition to lowering BP
SE: dry cough (bradykinin), hyperkalemia (dec. aldosterone), renal dysfunction (e.g. in renal artery stenosis ATII is important in maintaining GFR), angioedema (rare)
Angiotensin Receptor Blocker
- prototype
- actions
Prototype: LoSARTAN
Actions: same as ACEi, except no bradykinin build-up (no cough, but less vasodilation)
Renin Inhibitors
- prototype
- actions
Prototype: AliskiREN
Actions: same as ARBs
Calcium channel blockers
-general actions
Actions: targets L-type channel in cardiac myocytes and vascular smooth muscle, decreases Ca influx and therefore the force of contraction.
Types of CCBs
- differences
- SE
1) Dihydropyridines (e.g. nifedIPINE) acts more on the vasculature. SE include reflex tachycardia from low BP (exacerbates arrhythmias)
2) Non-dihydropyridines act on the heart more. SE include cardiodepression
- Benzothiazepines (e.g dilTIAZem)
- Phenylalkylamines (e.g. verapAMIL)
Beta antagonists
-subtypes
Cardioselective (B1): MetoproLOL
Non-cardioselective: propranoLOL (B1,B2), carvediLOL(B1,B2,A1)
Partial agonists: acebutoLOL (B1)
Beta antagonists
- actions
- SE
Actions:
Decrease HR, contractility
Decrease renin secretion
Decrease SNS activity
SE: Bronchoconstriction in non-selective (therefore contraindicated in asthma) and fatigue due to reduced CO
Alpha-1 antagonists
- prototype
- actions
- SE
Prototype: praZOSIN
Actions: vasodilatory and venodilatory
SE: orthostatic hypotension
Vasodilators
- prototype
- actions
- frequency of use
Prototype: hydralazine
Actions: decrease SVR
Use: rarely used
CNS (central) agents
- prototype
- mechanism
- actions
Prototype: A2 agonists (Clonidine)
Mechanism: feedback inhibition of NE release
Actions: dec. HR, SV and TPR
Why use combination therapy?
Because the body has compensatory mechanisms that we need to counteract
Aldosterone antagonists
- prototype
- AKA
Prototype: spironolactone
AKA K+ sparing diuretics
