Drugs for Hypertension Flashcards
normal BP
Below 120/80 mm Hg
Prehypertension: (BP)
120-139/80-89
Stage 1 hypertension
140-159/90-99
Stage 2 hypertension
greater than of equal to 160/100
Primary (essential):
no identifiable cause
secondary
due to identifiable cause
Joint National Committee, 7th Report
Target BP <130/80 for patients w/Diabetes Mellitus or Chronic Kidney Disease
3rd leading cause of death throughout the world
“Essential” or “Primary” Hypertension
“Essential” or “Primary” Hypertension is 1 in every _____ deaths worldwide
8
what percent of americans of hypertension stage one
30%
In people under 80, lowering blood pressure
reduces the risk of stroke by 40%; %. It also cuts their odds of a heart attack by 27 % and heart failure by 54%
The risk of CVD
beginning with a blood pressure of 115/75 mm Hg, doubles with each increment of 20/10 mm Hg
Consequences of Hypertension
Heart Disease; Angina; Myocardial Infarction; Renal- disease; Stroke; Peripheral artery disease; Retinopathy
heart disease
Left ventricular hypertrophy (enlarged left ventricle)
Peripheral artery disease
poor circulation
Why do we treat blood pressure?
• For every 20 mm Hg increase in normal systolic blood pressure from ages 40 to 69, mortality from ischemic heart disease and stroke doubles.
Untreated Systolic Blood Pressure has been shown to be a more important predictor of
mortality and CV complications than untreated elevated Diastolic Blood Pressure
Factors Increasing Cardiovascular Risk
Cigarette smoking; Obesity; inadequate exercise; dsylipidema; diabetes; Family history of premature cardiovascular disease; Advancing Age; Microalbuminemia
Microalbuminemia
(spilling protein into urine)
dyslipidemia
high cholesterol
Necessary Lifestyle Changes
Weight loss; Sodium restriction (2000 mgs per day); Fruits, vegetables, low-fat dairy , low total fat (30% of calories), low saturated fats, low cholesterol; Alcohol restriction; aerobic exercise; Smoking cessation; Potassium and calcium intake (fruits and veggies)
arterial pressure =
cardiac output x peripheral resistance
Is there a rule of thumb when starting BP drugs?
Initiate therapy with 2 drugs, either separately or in a fixed-dose combination in patients with SBP greater than 20 mm Hg above the desired goal; One component should usually be a thiazide-type diuretic but other combinations may be appropriate
diuretics
reduce preload
beta blockers
”olols”, “alols”, “ilols”—decrease contractile state of heart and heart rate (decrease cardiac output)
ACE inhibitors
the “prils”—block AT2 via ACE inhibition
ARBs
the “sartans”—block AT2 tissue receptors
Drugs that block aldosterone
spironolactone, eprelrenone
Calcium channel blockers
the “dipines” and others—block calcium channels on peripheral vessels
Alpha-1 blockers
the “osins”—rarely used for hypertension; (prazosin/Minipress
Alpha-2 agonists
act within brainstem to suppress sympathetic outflow to heart and blood vessels (clonidine/Catapres)
Vasodilators
hydralazine/Apresoline, minoxidil/Loniten, sodium nitroprusside/Nipride, nitroglycerine
Antihypertensive mechanisms: sites of drug action
Brainstem; Sympathetic ganglia; Terminals of adrenergic nerves; Beta1-adrenergic receptors on the heart; Alpha1-adrenergic receptors on blood vessels; Vascular smooth muscle; Renal tubules; Beta1 receptors on juxtaglomerular cells; Angiotensin-converting enzyme; Angiotensin II receptors; Aldosterone receptors
Hydralazine (Apresoline)
Direct-acting vasodilator of arterioles; Peripheral resistance and arterial BP decrease
Hydralazine (Apresoline) can cause
tachycardia, palpitations, nausea, anorexia, reflex Systemic Lupus Erythematosus Syndrome, increased blood volume
Because of minimal venous dilation with Hydralazine (Apresoline) risk of
orthostatic hypotension is low
Sodium Nitroprusside (Nipride) mixed with
Mixed arterial and venous vasodilator
Sodium Nitroprusside (Nipride) given to
Given to rapidly reduce blood pressure in clients with hypertensive crisis
Sodium Nitroprusside (Nipride)
IV drug, light sensitive (must be covered in dark colored bag); Cyanide is a metabolite of this drug
Sodium Nitroprusside (Nipride) result of prolonged use
Cyanide poisoning may result from prolonged use
Clonidine (Catapress)
Centrally acting antihypertensive (acts on brain stem)
Clonidine (Catapress) called
an alpha 2-agonists –by activating central alpha 2 receptors in brain, clonidine reduces sympathetic outflow to blood vessels and heart. Result? major vasodilation-and bradycardia
Clonidine (Catapress) side effects
: drowsiness, poor concentration, forgetfulness, vivid dreams, dry mouth
Clonidine (Catapress) abrupt withdraw
will result in rebound hypertension
do not use Clonidine (Catapress) in
pregnancy
with Clonidine (Catapress) major severe pain with
cancer pts
methyldopa (Aldomet) similar
same class) as clonidine (Catapres)
methyldopa (Aldomet) inhibits
sympathetic outflow to blood vessels-vasodilates
methyldopa (Aldomet) can lead to
hemolytic anemia (10-20% chance) -withdraw drug immediately (monitor for +Coombs test-of the patients who have a Coombs, only 5% develop hemolytic anemia)
when pt pregnant this is the DOC
methyldopa (Aldomet)
Coombs test detects
presence of antibodies directed against patient’s own red blood cells
Prazosin hydrochloride (Minipress)
Peripherally acting alpha1-adrenergic blocking agent (sympatholytic)
Prazosin hydrochloride (Minipress) dilates
both arteries and veins
Prazosin hydrochloride (Minipress) treats
mild to moderate hypertension
with Prazosin hydrochloride (Minipress)
Watch for first dose syncope; major orthostatic hypotension
