L14, L16- Antihypertensive Drugs Flashcards
list the classifications of HTN
- Normal: <120/<80
- Elevated: 120-129/<80
- Stage 1 HTN: SP 130-139, or DP 80-89
- Stage 2 HTN: SP >140, or DP >90
although most cases of HTN have a (1) cause, the mechanism is the same, described as (2)
1- unknown
2- inc peripheral vascular smooth muscle tone –> inc arteriolar resistance + dec capacitance of venous system
BP control is dependent on (1) which is controlled by (2) and (3) which is dependent on (4).
1- arterial BP (proportional to CO, PVR)
2- SNS, RAAS
3- CO, PVR
4- baroreceptors / ANS, RAAS
the main compensatory responses to decreased BP and adverse effects of antihypertensives are….
-tachycardia
-Na/H2O retention
(both aim to inc BP)
Stage 1 HTN is treated with (1) and Stage 2 with (2). (3) is recommended for both.
1- single drug
2- multiple drugs
3- lifestyle recommendations
list the 1st line HTN agents
- ACE inhibitors / ARBs
- Ca channel blockers
- thiazides
list the 2nd line HTN agents
- β-blockers
- aldosterone antagonists (K+ sparing diuretics)
list the 3rd line HTN agents
- loop diuretics
- α-blockers, central α2-agonists
- direct vasodilators
- renin inhibitors
list the main ACE inhibitors
- lisinopril
- enalapril
- captopril
ACE inhibitors are (1st/2nd/3rd) line HTN drugs, and are preferred in (2) patients. Its use will result in decreased (3) and increased (4). (5) is also an important absent reaction seen with these drugs.
1- 1st
2- DM, CKD Pts (over thiazides, Ca-channel blockers)
3- PVR, Na/H2O retention
4- bradykinin
5- no barorecptor reflex => inc HR/contractility (SV)/CO
renin release occurs in response to the following….
- dec renal perfusion
- renal SNS activity
- dec GFR
- β-agonists, PG-I2
compare renin, angiotensin I, angiotensin II levels in ACE inhibitors vs ARBs
ACE: inc renin, inc angio-I, dec angio-II
ARBs: inc renin, inc angio-I, inc angio-II
ACE inhibitors are more effective in (1) patients, but if combined with (2) it will equally effective in (3) patients. It is used in (4) patients because it will (5).
1- white, young patients
2- diuretic
3- black/all patients
4- DM, CKD
5- preserve renal function (no glomerular HTN)
in addition to HTN, ACE inhibitors are effective treatments for….
- chronic HF
- post-MI MI prevention (no acute action, but prevents recurrence)
describe the effect of ACE inhibitors and ARBs on GFR
dec GFR: causes efferent arteriole dilation
-usually a benign or insignificant effect unless patient has previous kidney disease history
list the adverse effects of ACE inhibitors
- dry hacking cough (via bradykinin)
- hyperkalemia (via dec Na retention via dec aldosterone)
- hypotension
- angioedema (bradykinin, rare)
- ARF in patients with bilateral RAS
- rash, fever, altered taste
list the contraindications for using ACE inhibitors
- Pregnany: congenital malformation in 1st trimester, fetal hypotension, anuria, renal failure in 2nd/3rd
- Pts with bilateral RAS
- Pts with previous h/o angioedema
the main ARBs are….
- losartan
- valsartan
ARBs are (1st/2nd/3rd) line agents in HTN treatment, and are alternatives to (2) because of (3). They function by blocking (4) leading to decreased (5), and importantly unchanged (6) which is increase with (2) use.
1- 1st line
2- ACE inhibitors
3- intolerance, usually cough via bradkinin
4- angiotensin-II type 1 receptors
5- dec BP (via arteriolar, venous dilation), dec Na/H2O retention, dec diabetic nephropathy
6- bradykinin levels (unchanged)
list ARB’s adverse effects
- hyperkalemia (via dec Na retention via dec aldosterone)
- hypotension
- ARF in patients with bilateral RAS
- rash, fever, altered taste
- angioedema (rare + lower than in ACEI use)
- losartan: reduces [uric acid] in plasma (via URAT1 transporter inhibition) –> useful in, but not a Tx for, gout
(NO dry hacking cough via bradykinin)
list the contraindications for ARB use
- pregnancy
- patients with bilateral RAS
the main renin inhibitor is (1), which inhibits renin so (2) cannot occur, and has (3) as the end result
1- Aliskiren
2- conversion of angiotensinogen (via liver) to angiotensin-I
3- inhibits angiotensin-II and aldosterone
what are the adverse effects of Aliskiren
(renin inhibitor)
- hyperkalemia (via dec Na retention via dec aldosterone)
- hypotension
- ARF in patients with bilateral RAS
- rash, fever, altered taste
-angioedema (rare + lower than in ACEI use)
(NO dry hacking cough via bradykinin)
list the Ca channel blockers by class
- Non-dihydropyridines: verapamil, diltiazem
- Dihydropyridines: nifedipine, amlodipine
Ca channel blockers are (1st/2nd/3rd) line drugs for HTN treatment, mainly for (2) patients
1- 1st
2- black, elderly patients (since ACEI’s are more effective in young, white people)
Verapamil is a (1) type antihypertensive which has effects on (2) and is used to treat (3)
1- Ca channel blocker, non-dihydropyridine
2- cardiac and vascular smooth muscle (inhibits contraction??)
3- angina, suprventricular tachyarrhythmias, HTN, migraines, cerebral vasospasm
Diltiazem is a (1) type antihypertensive which has effects on (2) and is used to treat (3). It is also useful because of (4).
1- Ca channel blocker, non-dihydropyridine
2- cardiac and vascular smooth muscle (inhibits contraction??)
3- angina, suprventricular tachyarrhythmias, HTN, cerebral vasospasm
4- good side-effect profile
Amlodipine is a (1) type antihypertensive which has great effects on (2) in comparison to (3). It functions to reduce (4), causing (5). It is also used to treat (6).
1- Ca channel blocker, dihydropyridine
2- vascular smooth muscle Ca channels
3- cardiac smooth muscle Ca channels
(non-dihydropyridines (diltiazem, verapamil) have equal affinities)
4/5- dec Ca entry into smooth muscles –> coronary / peripheral vasodilation –> low BP
6- n/a, primarily for HTN
Nifedipine is a (1) type antihypertensive which has great effects on (2) in comparison to (3). It functions to reduce (4), causing (5). It is also used to treat (6).
1- Ca channel blocker, dihydropyridine
2- vascular smooth muscle Ca channels
3- cardiac smooth muscle Ca channels
(non-dihydropyridines (diltiazem, verapamil) have equal affinities)
4/5- dec Ca entry into smooth muscles –> coronary / peripheral vasodilation –> low BP
6- n/a, primarily for HTN
Ca channel blockers specifically inhibit (1) channels to limit entry of Ca. Ca normally has (2) function in the cell membrane of smooth muscle cells and (3) function elsewhere. Overall, Ca channel blockers function to cause (4) in smooth muscle cells.
1- V-gated Ca channels, L-type (long-lasting)
2- inc Ca (out) / Na (in) exchange [rapid Ca out or into SR dec refractory period, inc HR + contractility] –> inc Na (out) / K (in) exchange
3- inc quantity of Ca release from –> inc free Ca
4- inc myofibril vascular relaxation by dec free Ca in cytoplasm