Antihypertensives Flashcards
Organ damage from hypertension
Cerebrovascular disease
Hypertensive retinopathy
Left ventricular dysfunction
Left ventricular hypertrophy
Coronary artery disease (MI, angina, CHF)
Chronic Kidney Disease
Peripheral artery disease
BP target for high risk
Less than 120 systolic
BP target for general population
Less than 140 systolic and 90 diastolic
Target BP for diabetics
Less than 130 systolic and 80 diastolic
Antihypertensive drug categories
•Angiotensin converting enzyme inhibitors (ACE inhibitors)
•Angiotensin II receptor blockers (ARBs)
•Calcium Channel Blockers (CCB)
•Diuretics
•B-adrenoreceptor blockers
•Vasodilators
•Adrenergic agents
ACE Inhibitors
•First line treatment for HF and hypertension
•Often combined with thiazide diuretic or calcium channel blocker
•Nagging cough
DRUGS: end in “pril”
Capropril: shortest half-life
Enalapril (vasotec): Available oral and parenteral
ACE inhibitor indications
Hypertension
Heart failure
Renal protective effects in diabetes
ACE Inhibitor mechanism of action
•Prevents conversion of angiotensin I to angiotensin II
•Reduces peripheral resistance (afterload)
•Prevents Aldosterone release, thus reducing salt/water reabsorption
•Prevents breakdown of bradykinin which causes vasodilation
ACE inhibitor adverse effects and interactions
•Nagging dry cough
•Hypotension
•Possible hyperkalemia
Interactions/CI
•K-sparing diuretics
•Contraindicated during pregnancy
Angiotensin II receptor blockers (ARBs)
•Similar to ACE
•Does NOT cause dry cough
•Angiotensin II receptor antagonist. blocks receptors that ang II activates.
•Blocks ang II mediated vasoconstriction
•Blocks release of aldosterone
•Drug names end in “sartan”
DRUGS:
Losartan
ARBS indications
•Hypertension
•Heart failure
•Used with or without other agents: CCBs, Diuretics.
Alternative for those who can’t handle ACE inhibitors
contraindicated in pregnancy
Calcium Channel Blockers (CCBs)
•For hypertension, angina, dysthymias
•Block cardiac muscle Ca channel
•Alters electrical activity of cardiac muscle cells at SA and AV nodes and cardiac muscle
•Vascular: inhibits Ca entry into arteriolar vascular smooth muscle cells, causing relaxation
•Decreased peripheral resistance
DRUGS:
•Benzothiazepines (cardiac/vascular): Diltiazem
•Phenylalkamines (cardiac/vascular): Verapamil
•Dihydropyridines -DHPs-Vascular selective): Amlodipine, nifedipine
CCB: Diltiazem
Cardiac & vascular
CCB: Verapamil
Cardiac & vascular
CCB: Dihydropyridines (DHPs)
Vascular selective.
Cause muscle cells to relax
Drugs end in “pine”
Amlodipine
Nifedipine
Verapimil and Diltiazem Adverse Effects
Cardiovascular: hypotension, flushing, peripheral edema
GI: Constipation, nausea
DHPs (amlodipine, nifedipine) Adverse effects
Cardiovascular: hypotension, palpitations, tachycardia, flushing, peripheral edema
GI: Very little constipation
Thiazide and Thiazide-like Diuretics
•Decrease plasma and extracellular fluid
•Decreased preload, decreased cardiac output, decreased total peripheral resistance
•First line Tx in hypertension
DRUGS
hydrochlorothiazide
-Risk for hypokalemia, digoxin interaction
-Longer-acting thiazide preferred over short/acting
Beta-Adrenergic Blockers (Beta blockers)
•Act in periphery, mainly heart
•Blocks epinephrine/norepinephrine action on receptors in heart
•Decreases force of heart muscle contraction and decreases heart rate
•Not indicated as first-line for age over 60
DRUGS: end in “lol”
Metaprolol: B1-selective
B-Blocker Indications and considerations
Hypertension
HF
Angina
Dysrhythmia
•Intolerance to exercise
•Avoided in asthma patients
If hypertension not controlled, or there are adverse effects, other classes of antihypertensive drugs may be combined, such as..
Alpha blockers or centrally acting agents
Centrally acting a2 receptor agonists
•Stimulate a2 receptors in brainstem
•Norepinephrine release decreased
•Sympathetic NS outflow decreased
•Vasodilation: decreased BP
Indications:
•Tx of hypertension, alone or with other drugs
•Used after other agents have failed, or used in combo with other drugs
DRUGS:
Methyldopa: First line for HPTN in pregnancy
Adverse Effects of Adrenergic Agents (a-receptors)
Most common:
•Dry mouth
•Drowsiness/sedation
•Constipation
High incidence of orthostatic hypotension
Client implications
•Drugs should not be stopped abruptly as this can cause a rebound hypertensive crisis (stroke risk)
•Clients should avoid smoking, avoid eating foods high in sodium.
•Change positions slowly to avoid syncope and postural hypotension
•Avoid aggravating low blood pressure (hot tubs, baths, hot weather, prolonged sitting/standing, intense exercise, alcohol)
