Drugs for Hypertension Flashcards
What drugs can be used as monotherapy to decrease BP in 40-60% of patients (mild hypertension)?
Thiazide diuretics due to short term effects of decreasing body Na+, which leads to the long term effects of activating K+ channels and causing further hyperpolarization of VSMC, producing more of a vasodilation effect
What diuretic is considered a direct vasodilator?
Indapamide
What are the thiazide diuretics?
Hydrochlorothiazide, chlorothiazide, methlazone, quinethazone, chlorthalidone, indapamide
What are some side effects of thiazide diuretics? How do you solve this problem?
ED, gout, increased renin, REDUCED GLUCOSE TOLERANCE and INCREASED PLASMA LIPID CONCENTRATION; lower the dose
What is the DOC for HTN?
Thiazide diuretic
What happens every time you decrease blood pressure?
Increased renin release!
When should you reconsider thiazides?
sulfa allergies
In whom are thiazide diuretics most effective?
African Americans>Caucasians, Elderly>younger
When are loop diuretics used?
In renal insufficiency, CHF
What drugs should you not use with potassium sparing diuretics?
ARBs or ACE-Is
Since sympatholytics activate the baroreflex and lead to an increase in Na+ and H2O retention, what should you combine it with?
a diuretic
What are the therapeutic effects seen by sympatholytics?
decreased sympathetic outflow leads to decreased renin secretion, Clonidine will decrease HR and CO more than methyldopa
What two drugs are found in the sympatholytic class?
Clonidine and methyldopa
What is the DOC for HTN in PGN?
Methyldopa
What are some common side effects of sympatholytics? More serious?
Minor: sedation, CNS, xerostomia; Serious: HEMOLYTIC ANEMIA WITH A POSITIVE COOMBS TEST (decreased Hgb)
What are some precautions with sympatholytics? clonidine esp?
Not recommended for mootherapy, no TCA or yohimbine; SUDDEN WITHDRAWAL LEADS TO SEVERE REBOUND HTN
Which drug class is known to have a first dose response of severe orthostatic hypotension?
alpha 1 antagonists because baroreflex is completely inhibited
What drug would you use to block vasoconstriction if you were worried about elevating plasma lipids?
alpha 1 antagonists because they have no effect on insulin release!
What other disease may alpha 1 blockers have efficacy in?
BPH
What is the effect of alpha 1 blocker on renin? heart rate?
increased renin, some reflex tachy but not as much as there is with alpha 2 blockers
What are the non-selective B blockers?
(The letter N and below)
Propranolol, nadolol, timolol
What are the selective B1 blockers?
(The letter N and above except for nebivolol )
Metoprolol, atenolol, nebivolol, acebutolol
What are the B blockers with intrinsic sympathetic activity (ISA)?
acebutolol and pindolol, act as partial agonists. (decreased risk of bradycardia and bronchoconstriction, less effect on lipids)
What population are B blockers more effective in?
Caucasians>black
Young>elderly
(recommended for monotherapy only in young white males)
Why must B-blockers be combined with other drugs?
To counteract the effects of reflex tachycardia and increased renin secretion
What drugs are contraindicated in DM?
Thiazides and Bblockers
When are B Blockers preferred?
Angina, Post MI, migraine
When are B Blockers least preferred?
High physical activity, Blacks, asthmatics, DM, high cholesterol, PVD
When is labetalol indicated?
to decrease BP in hypertensive emergencies and in pregnancy, not used first line because of hepatotoxic effects!
What are the combined A1 and B Blockers? What is the benefit of using them?
No reflex tachycardia due to B2 blockade along with vasodilation
What are adverse effects of A1 and B blockers?
Orthostatic hypotension, bronchospasm, and HEPATOTOX
Why do the effects of vasodilators diminish overtime?
because reflex tachycardia leads to increase in renin secretion, so they work best with other drugs
When are hydralazine, minoxidil and CCB given?
for chronic, oral treatment of HTN
When are nitropress, fenoldopam, and some CCBs used?
IV for emergencies!
What are sx that may accompany vasodilator admin?
reflex tachy, increased renin, fluid retention, HA and FLUSHING
When is carvedilol indicated?
HTN and CHF, especially post MI
When is hydralazine indicated? What is its MOA?
Used in chronic therapy of severe HTN only if other treatments have failed (also severe HTN or severe HTNive emergencies in PGN); DILATES ARTERIES
What are adverse effects of hydralazine?
HA, nausea, angina, SLE in slow acetylators
What are the indications for Sodium nitroprusside?
Rapidly lowers BP, effects wear off right after discontinuation, USED IN HTNIVE EMERGENCIES, IV only, dose-response curve, VENODILATION
What are severe adverse reactions of sodium nitroprusside?
Cyanide accumulation, Acidosis, death if pts can’t metabolize cyanide
What is the one K+ channel regulator? What is its MOA as a result?
opens potassium channels to stabilize the VSMC membrane, so it dilates arterioles but not veins
What are some adverse side effects of minoxidil?
headache, sweating, HYPERTRICHOSIS (Rogaine=topical)
What vasodilator has effect on post synaptic D1 receptor to relax arteriolar smooth muscle? When is it used? How is it administered?
Fenoldopam, primarily renal vasculature, emergency HTNive situations, IV administration
What are the major effects of CCBs?
Negative ionotropic effect due to decreased contractility, reduced impulse generation in the SA node, and slowed AV nodal conduction
Rank Nifedipine, Verapamil, and diltiazem in terms of vasodilation and cardiac effects
Nifedifpine is the strongest vasodilator (causes most reflex tachy), verapamil has the strongest cardiac effects (will decrease HR the most), and Diltiazem is more cardiospecific than the dipines and it tends to decrease HR
What are three major adverse side effects of dihydropyridines (-dipines)?
Gingival hyperplasia, and vascular side effects (HA, flushing, dizziness, edema)
What is a major side effect of verapamil?
Constipation
What is one relative contraindication of CCBs?
patients with LVH
What are two absolute contraindications of verapamil and diltiazem?
SA/AV node abnormalities, CHF (don’t use any CCBs in CHF, but esp not these)
What do ACE inhibitors not cause that all vasodilators and blockers can cause? Why?
reflex sympathetic activation (or tachycardia); baroreceptor resetting
If you are concerned about side effects and lipid changes for your pt with HTN, what drug should you use?
ACE-Inhibs, they lower BP without compromising the heart, brain, or kidneys
In addition to thiazides, what other drug can be given orally for mild to moderate htn?
ACE-I, also enhances efficacy of other diuretics
Who are ACE-I most effective in?
Young and middle-aged caucasians
Who are they least effective in?
Elderly African Americans
In which populations are ACE-I the first choice for HTN tx in?
Diabetes, Chronic renal disease, and LVH (due to vasodilation)
What other medication for HTN should you not prescribe with ACE-I (contraindication)?
Aldosterone antagonist (possible to cause severe hyperkalemia)
What cautions should you watch for with ACE-inhibs?
Severe hypotension in hypovolemic pts, dry hacking cough, angioneurotic edema, hyperkalemia due to decreased aldosterone, may cause acute renal failure in patients with bilat renal artery stenosis
Which BP med is contraindicated in pregnancy? What other contraindications exist for this med?
ACE-inhibs; K+ sparing diuretics, NSAIDS with decrease vasodilation because bradykinin aids in PG synthesis
What drugs are Angiotensin receptor blocking agents?
-sartans!
