antihypertensives Flashcards
hypertension -elevated state
SBP 120-129
DBP <80
Hypertention-stage I
SBP 130-139
DBP 80-89
Hypertension -stage II
SBP >140
DBP >90
Antihypertensives target
decrease CO
decrease peripheral resistance
first line agents
ACE-inhibitors, ARBs, calcium channel blockers,
thiazide diuretic
second line agents
b-blockers, aldosterone antagonist
ace inhibitors
Captopril / Enalapril / Lisinopril
ACE inhibitors MOA ?
• BP by peripheral vascular resistance
• INHIBIT ACE (angiotensin converting enzyme) that
cleaves angiotensin I to form angiotensin II
• DECREASE Na+ & H20 retention
• INCREASE BRADYKININ levels
• DO NOT reflexively increase cardiac output, rate or
contractility
ACH inhibitors clinical uses
• Hypertension (most effective in white and/or young patients) + diuretic = effectiveness similar in non-black and blackpatients
• Preserve renal function in patients with either diabetic or non-diabetic nephropathy
• Effective in treatment of chronic HF
• Standard of care for patients following MI (started 24h
after end of infarction)
AE of ACE inhibitors
• Dry hacking cough • Hyperkalemia • Hypotension • Angioedema (rare but life-threatening) • Acute renal failure (patients with bilateral renal artery stenosis) • Rash, fever, altered taste
ACE inhibitors contraindications
> Pregnancy
> Patients with bilateral artery stenosis
ARBs
Losartan
valsartan
ARBs MOA
- Angiotension receptor blockers (ARB’s)
- First-line agents
- Alternatives to ACEI’s (in intolerant patients)
- Block angiotensin-2 type 1 receptors
- BP by causing arteriolar & venous dilation
- Block aldosterone secretion à decrease Na+ & H20 retention
- diabetic nephrotoxicity
- DO NOT INCREASE BRADYKININ levels
ARBs AE
• Hyperkalemia
• Hypotension
• Angioedema (lower risk than ACE inhbit)
• Acute renal failure (patients with bilateral renal artery
stenosis)
• Rash, fever, altered taste
Losartan reduces plasma uric acid levels by inhibiting
URAT1 transporter – can be useful in patients with
gout
Special use of losartan
Losartan reduces plasma uric acid levels by inhibiting
URAT1 transporter – can be useful in patients with
gout
ARBs contraindications
Pregnancy
• Patients with bilateral renal artery stenosis
Aliskiren
Renin inhibitor
Renin inhibitor MOA
Alternative agent in the treatment of hypertension
MOA
• Inhibits enzyme activity of renin and prevents
conversion of angiotensinogen into angiotensin I
End result:
• Inhibits production of both angiotensin II and
aldosterone
Aliskiren AE
• Similar to those of ACE inhibitors
• Dry cough does not occur (due to no effect on
bradykinin levels)
• Angioedema risk is significantly lower than with
ACEI’s
CCA blockers
Verapamil / Diltiazem / Nifedipine / Amlodipine
Non dihydropyridines CCA blockers
- Verapamil
* Diltiazem
dihydropyridines CCA blockers
Nifedipine, amlodipine
verapamil overview and uses
- Least selective of any Ca2+-blocker
- Significant effects in cardiac & vascular smooth muscle
> to treat angina, supraventricular
tachyarrhythmias, hypertension, migraine & cerebral
vasospasm
dilitiazem uses
Used to treat angina, hypertension, supraventricular
tachyarrhythmias & cerebral vasospasm
CCA applications
• Hypertension (particularly black and/or elderly
patients)
• Have intrinsic natriuretic effect (no need for diuretic)
• Useful in patients with asthma, diabetes, peripheral
vascular disease
CCA blocker PK
• High-doses of short-acting dihydropyridine Ca2+-
channel blockers can increase risk of MI
verapamil AE
Constipation (~7%), negative inotropic effects, gingival
hyperplasia
dihydropyridine AE
Hypotension, peripheral edema (esp. feet & ankles),
dizziness, headache, fatigue, gingival hyperplasia,
flushing, reflex tachycardia can occur (especially in
short-acting preparations)
contraindications Non-dihydropyridines
Relatively contraindicated in patients taking b-blockers,
or who have 2nd or 3rd degree AV block, or severe left
ventricular systolic dysfunction
