Anti-HTN Drugs Flashcards
Prehypertension SBP and DBP?
SBP 120-139 or DBP 80-89
Stage 1 HTN
SBP 140-159 or DBP 90-99
Stage 2 HTN
SBP >160 or DBP >100
alpha 1 blockers
Prazocin, Doxazocin, Terazocin
Beta blockers (non-specific)
Propanolol, carvedilol, pindolol, timolol
B1 specific blockers
Metoprolol, atenolol, bisoprolol, nebivolol
Third generation b1 specific blockers
bisoprolol, nebivolol
ACE inhibitors
Captopril, Lisinopril, Enalapril, Ramipril
AR blockers
Losartan, valsartan, irbesartan, telmisartan, candesartan
Renin inhibitor
aliskerin
L-type Ca channel blocker- Phenylalkylamine
Verapamil
L-type Ca channel blocker- Benzothiazepine
Diltiazem
L-type Ca channel blockers- Dihydropyridine
Amoldipine, nifedipine, nicardipine, nimodipine
Centrally acting alpha-2a agonists
clonidine, guanabens, gaunfacine, methyldopa
Direct vasodilators
Minoxidil, sodium nitroprusside, diazoxide, fenoldopam
site of action for alpha-1 blockers
arteries and veins
effects of alpha-1 blockers
decrease TPR, reduce BP, relieve BPH symptoms. Also increase HDL, lower LDL, and has a beneficial effect on insulin resistance
side effects of alpha-1 blockers
first-dose hypotension (particularly with Prazosin; give at bedtime)
orthostatic hypertension is a problem with?
alpha antagonist, Prazosin
B blockers with ISA (Intrinsic Sympathomimetic activity)?
Timolol and Pindolol (aka Timon and Pumba have Simba)
B blockers with MSA (membrane stabilizing activity)?
Propanolol, metoprolol pindolol
B blocker that prevents LDL oxidation and uptake in the coronary arteries?
Carvedilol
B blocker that has antioxidant capability and promotes NO-mediated vasodilation
Nebivolol
B blockers with Cardioselectivity
Metoprolol and bisoprolol
Effects of BB with no ISA?
decrease HR, decrease contractility, decrease CO, block B1-AR in juxtaglom. app. thereby inhibiting renin release
BB with no ISA useful in what patients?
high renin hypertension (also work well in hypertensive patients with normal-low renin)
B blockers effective therapy in what grades of HTN?
All grades
Get an additive effect when combining BB with?
diuretic
Associated with definite mortality benefits?
bisoprolol
Mixed alpha 1 and beta antagonist?
Labetalol and Carvedilol
labetalol uses?
IV for hypertensive emergencies. Pheochromocytoma and preeclampsia
BB that protects membranse from lipid peroxidation?
Carvedilol
Clinical use of 3rd gen b-blockers
CHF and HTN
Why are 3rd gen BB better for CHF and HTN?
- reduce bp more than other b-blockers because of additional alpha blockade (carvedilol labetalol) and N.O. (nebivolol) 2. reduce HR less than other b blockers, decreased mortality and morbidity in CHF patients 3. Not associated with changes in lipids and glucose, preferred in metabolic syndrome
Drug for open angle glaucoma?
Timolol
Timolol MOA?
reduces production of aqueus humor
BB has a compelling indication for?
HTN patients with hyperthyroidism and migraines
Drugs that can worsen peripheral arterial insufficiency (cold)?
1st and 2nd generation BB
Side-effects of 1st and 2nd gen BB
- bradycardia, 2. bronchospasm (okay with COPD, no asthma) 3. bad dreams, 4. block glycogenolysis, delay recovery from hypoglycemia in T1D, 5. block HSL in adipocytes, increase LDL, increase triglycerides, decrease HDL
Abrupt withdrawal of BB causes
tachycardia due to upregulation of b receptors in the heart (should taper off)
ACE converts?
Ang I to Ang II, and degrades bradykinin. Also decreases secretion of aldosterone
Drug that directly blocks renin activity
aliskerin
Effect of captopril
increases synthesis of renal prostaglandins (delays progression of renal disease in diabetics, renoprotective)
ACE inhibitor effect on baroreceptors?
none (and no postural hypotension)
what converts angiotensinogen to Ang 1
Renin
difference between ang 1 and ang 2
ang 1 has 1-10 AAs, ang 2 has two less (1-8 AAs) Chymase cleaves the two
What are the various Ang 2 effects?
Cardiac/Vasc hypertrophy, systemic vasoconstriction, increased blood volume, Renal sodium and Fluid retention
Only way to treat CHF?
dilate the vasculature (achievable through ACE-I)
Most common side effect of ACE-I
Cough (potentially bradykinin related)
Side effects of ACE-I
- hypotension, in hypovolemic or Na-depleted patients 2. hyperkalemia, esp with renal insufficiency 3. Dry cough (bradykinin stretch receptors in the trachea 4. angioedema (secondary to inhibited bradykinin degradation) 5. Fetotoxicity (contra in 2nd/3rd trimester)
MOA of ARB
selectively block AT II type 1 receptors
Effect of ARBs
vasodilation, increase Na and h20 excretion. Thus they decrease TPR, plasma volume, CO, and BP
Pro-drug ARB
Losartan
MOA of Losartan
competitive antagonist of thromboxane A2 receptor, attenuates platelet aggregation
Unique effect of Losartan
increases uric acid urinary excretion
ARB drugs with no uric acid or CYP enzyme effects, yet have fetotoxicity risk
Irbesartan, valsartan, telmisartan (not renally excreted)
CCB contraindicated for someone with Wolf-Parkinson-White
Verapamil
3 classes of CCBs
Phenylalkylamines, benzothiazepines, dihydropyridines
CCB selective for myocardium, less effective vasodilator
verapamil
CCB intermediate-selective for vascular Ca channels
diltiazem
CCB selectively blocks L-type Ca channels in blood vessels
dihydropyridines
Dihydropyridines used for
HTN, as the decrease SVR and arterial pressure
How do DihydroP CCBs decrease BP
by relaxing arteriolar smooth muscle and decrease PVR
DihydroP CCBs are more effect in what type of patient
those with low renin: the elderly and African Americans. Also preferred in older subjects with systolic hypertension
Actions of clonidine, guanfacine, guanabenz
agonist of postsyn a2 in the rostral ventrolateral medulla (RVLM), decrease PVR and HR
Clonidine uses
analgesic (releases endogenous opiates), ADHD, HTN tertiary (not 1st or 2nd line therapy)
Which a2 agonist lowers cholesterol in plasma
guanabenz
Clonidine withdrawal associated with
hypertension
Hydralazine actions
arteriolar (not veins) smooth muscle relaxers (triggers reflex sympathetic stimulation)
side effects of hydralazine
pronounced tachycardia and hemolytic anemia
Selective d1 partial agonist, that is useful in septic shock
fenoldopam
Relaxes smooth muscle via opening K channels. Has hirsutism side effect
Minoxidil
Minoxidil uses
IV hypertensive emergencies, preeclampsia (generally used with BB and diuretics)
Afterload is…
aortic pressure that must be overcome by the Left ventricle
MOA of Nitroprusside
pro-drug, froms NO (stimulates smooth muscles guanyl cyclase), increases cGMP, causes relaxation
Effects of Nitroprusside
dilates both arteries and veins, reduces TPR and increases veinous pooling, decrease CO in normal subjects. Short half life. Use in patients with angina/MI
Best tolerated drugs for the monotherapy of HTN
Diuretics and ACE-Is
Patients who particularly require a diuretic for BP control
patients with edematous conditions (HF and renal insuf) Also, those with volume dependent hypertension (low renin)
Inability to respond to thiazides indicates
a problem with Na ingestion or excretion
Major advantage for B blockers
secondary protection in CAD … particularly useful in hypertensives with tachycardia, high CO, and/or high renin
How long should BB be tapered over (in discontinuation)
10-14 days
What is the standard BB chosen to be used with ACE-Is and diuretics
Bisoprolol (3rd gen)
what drug preserves renal function in patients with non-diabetic nephropathies?
captopril
What drug should be avoided in patients with hyperkalemia
ACE-I
What should the initial HTN agent be for patients with Diabetes
ACE-I