Antihypertensives Flashcards
Joint Nat. Committee says we should treat what BP for someone with DM/kidney disease and what BP without? What do they say is first-line therapy?
Over 140/90 without DM/kidney disease
Over 130/80 with DM/kidney disease
First line therapy = thiazide diuretic
What antihypertensives are these patients on..
- HF
- MI
- High CVD risk
- HF: Thiazide diuretic, B-blocker, ACEI, ARB, aldosterone antagonist
- MI: B-blocker, ACEI, aldosterone antagonist
- High CVD risk: Thiazide, B-blocker, ACEI, CCB
What antihypertensives are these patients on..
- DM
- CKD
- Stroke prevention
- Isolated systolic HTN
- DM: Thiazide diuretic, B-blocker, ACEI, ARB, CCB
- CKD: ACEI or ARB
- Stroke prevention: Thiazide diuretic, ACEI
- Systolic hypertension: Thiazide, CCB
Hypertensive urgency vs. crisis?
DBP over 120
Urgency with evidence of organ damage (BUN/creat inc)
Crisis with evidence of organ failure
Why wouldn’t we want a pt to take ACEI before surgery?
ACEI decrease preload leading the patient to be hypovolemic
Angiotensinogen, secreted by the ____ -> (Renin, secreted by the ____) -> AT1 -> (ACE) -> AT2 -> Aldosterone
What effects Do AT2 and Aldosterone have on preload/afterload?
Angiotensinogn by liver
Renin by kidney’s juxtaglomerular cells
Aldosterone INC preload
AT2 INC afterload (potent vasoconstrictor)
ACEI uses?
HTN, CHF, mitral regurgitation, post MI, diabetic neuropathy, CRI
More effective in DM patients
Reduces BP and cardiac load
What are some Angiotensin-1 receptor effects (belong to G-protein coupled receptors)?
Vasoconstriction (especially in afferent arterioles of glomeruli)
Increase NE release
Proximal tubular reabsorption of Na
Secretion of aldosterone from adrenal cortex
ACEI MOA? Name a few.
Block conversion of AT1 to AT2 through interaction with zinc ion of ACE (in endothelium)
Prevents vasoconstriction, sodium retention and SNS stimulation
PRILS! Lisinopril, captopril (capoten), ramipril, enalapril (vasotec), fosinopril, quinapril, benazepril
What’s the major difference between ACEI? Captopril vs. enalapril vs. lisinopril
Captopril onset 15-30 min, DOA 6-10h, E1/2t 2h (more redosing)
Enalapril onset 1-2h, DOA 18-30h (no rash/renal insufficiency bc lacks sulfhydryl group)
Lisinopril onset 1h, DOA 18-30h
ACEI side effects?
Note: in general, they are mild, good compliance
Prolonged hypotension intra-op!!! (Don’t have them take it before surgery!!)
Granulocytopenia, angioedema, proteinuria, persistent cough, hyperkalemia
Captopril: rash, loss of taste
ACEI contraindication?
Renal artery stenosis (bc patients may develop renal failure due to efferent arteriole constriction)
ARB MOA? Name some.
Competitive binding to inhibit AT2 at its receptor, blocks AT2 without effecting ACE activity, results in decreased peripheral vasoconstriction
SARTAN! Losartan (cozaar), valsartan (diovan), irbesartan, candesartan, telmisartan, eprosartan
ARB side effects and contraindication?
SE: similar to ACEI but less cough and no bradykinin accumulation
CI: renal artery stenosis, pregnancy
Hydralazine is a ____ derivative, what does this do? Does it work more on arteries or veins?
Arterial vasodilator. Phthalazine derivative which activates gaunylate cyclase producing relaxant effect on vascular smooth muscle.
ARTERIES > VEINS
Hydralazine dose? When does it peak?
2.5-10 mg IV
10-20 min peak (this is a LONG time in surgery), lasts up to 6h
Hydralazine pharmacokinetics?
Extensive hepatic first pass metabolism
Onset 15 min, give slow
E1/2t 3h
15% unchanged in kidney
Hydralazine side effects?
Reflex tachycardia! Tachyphylaxis, tolerance DBP reduced more than SBP Dec SVR Inc HR, SV, CO Na/ H2O retention, EKG changes, angina Drug induced lupus- rash, joint pain
Minoxidil MOA, uses?
Directly relaxes ARTERIAL smooth muscle (little effect on venous) by increasing influx of K into smooth muscle, hyperpolarize, vasodilate
Used to treat HTN due to renovascular disease, renal failure, transplant rejection
Minoxidil pharmacokinetics?
90% oral dose absorbed from GI
Peak in 1 h
E1/2t 4h
10% unchanged in urine
Minoxidil side effects?
Inc HR, CO
Inc plasma concentration of NE, renin (retains Na/H2O, weight gain, edema, hypertrichosis, pulm HTN, pericardial effusion)
Abnormal EKG (flat/inverted T wave)
What are peripheral vasodilators used for? Name some.
Facilitates forward LV flow in AR, MR, HF
Controlled hypotension in OR
Treat hypertensive crisis
Nitroglycerine, nitroprusside, isosorbid, dipyridamole, papverine, trimethaphan, diazoxide, adenosine
SNP (sodium nitroprusside, nipride) class? In general, what does it do?
Nonselective peripheral vasodilator, direct acting
Relaxes arterial and venous vascular smooth muscle
Lacks effects on nonvascular smooth/cardiac muscle