Chapter 23 Flashcards
Primary HTN
idiopathic
no known cause
Secondary HTN
caused by another disease
Peripheral Resistance
Friction in arteries as blood flows through vascular system
Autonomic nervous system plays a roll
greater resistance means greater BP
Blood Volume medications
Medications that affect blood volume may lower or raise B/P
ex: aldosterone
Vasomotor center
Reacts to information from baroreceptors & chemoreceptors to raise or lower blood pressure
Primary Antihypertensive Agents
Diuretics ACE inhibitors Angiotensin II receptor blockers Beta blockers Ca channel blockers
Diuretics action
Decrease BP by inhibiting sodium & water retention by kidneys this decreases fluid volume
Negative effects of diuretics
Cause loss of electrolytes
Increase urine flow
Reduce blood volume and cardiac workload
Reduce edema and pulmonary congestion
Types of diuretics
Thiazide & thiazide-like (HCTZ)
Potassium-sparing (Spironolactone)
Loop (Lasix)
Thiazide & thiazide-like diuretics
1st line Tx
Relatively safe & inexpensive
Primary adverse effect: potassium loss
Potassium-sparing diuretics
Modest diuresis
Primary adverse effect: potassium retention Concurrent use with ACE or ARB increases risk of hyperkalemia
Loop diuretics
Produce most diuresis
Adverse effects: dehydration, potassium loss
SNS Neurotransmitters
Alpha 1, 2
Beta 1, 2
Alpha 1
1—receptors in Arteriole smooth muscle (vasoconstrict to increase BP)
Alpha 2
receptors in Brain—inhibits (regulates) CNS output of epinephrine
Beta 1
receptors in Heart rate & strength of contraction, Kidneys
Release renin
Beta 2
receptors in skeletal muscle, bronchioles of Lungs (bronchodilation),
Ca channel blockers for HTN
Safe & well tolerated, hold for HR < 60, BP < 90/60
Treat constipation
Good for elderly and african americans
not use as monotherapy
pine
Verapamil
Ca2+ blocker
Non-selective- both blood vessels & cardiac arterioles
Block ca channels on myocardium & vascular smooth muscles, AV node
Verapamil side effects
HA, low BP, constipation, dysrhythmias, CHF, bradycardia, tachycardia, edema in feet & hands
constipation
Verapamil effects
↑ blood flow to the heart
↓ impulses through the AV node—
↓ workload of heart & slow heart rate; HTN, angina, dysrhythmias, atrial fibrillation
Diltiazem
Ca2+ blocker
blocks Ca+ channels in myocardium, relaxes coronary vessels & periphery-not in bowel Non-selective
Diltiazem uses
Atrial fibrillation, HTN, Angina, Vasospasm
Diltiazem side effects
vasodilation-HA, dizziness, dysrhythmias, peripheral edema, brady or tachycardia
Stevens-Johnson syndrome
Less constipation
DIPINES
Peripheral vessel calcium channel blockers
Block the myocardial & coronary arteries & peripheral vascular calcium channels
DIPINES side effects
BP < 90/60, dizziness, SOB
Vasodilation, crackles, HA, dysrhythmias,
peripheral edema, wt. gain, brady or tachycardia
*Serious, life threatening BP
ACE Inhibitors action
reduces levels of Angiotension II (a vasoconstrictor) & aldosterone
lowers peripheral resistance & ↓ blood volume
Reduces afterload
Used in DM PT’s
ACE inhibitors side effects
postural hypotension, hyperkalemia, renal failure Angioedema Cough Electrolyte imbalance
ACE inhibitors and African Americans
↑ risk for angioedema, can be fatal
Angiotension II Receptor Blockers-ARBs
“sartan”
Often combined with other drugs for management HTN
Used when PT can not use ACE inhibitor
ARBs action
Block receptors for angiotension II
Cause arteriolar dilation & increased sodium excretion
ARBs side effects
hypotension, rare angioedema
Adrenergic Antagonists
Betas work best for HTN
Beta–Adrenergic Blockers action
decrease heart rate and contractility
↓ conduction velocity through AV node
Blockade of Beta 1-receptors in kidney which inhibits secretion of renin & formation of angiotension II
Beta–Adrenergic Blockers Indications
First-line drug for hypertension
Angina, Dysrhythmias, Heart failure, Myocardial infarction
Beta–Adrenergic Blockers considerations
Non-compliance-impotence & ↓ libido
Beta–Adrenergic Blockers
Selective (effect beta 1 only) and Non-selective effect beta 1 & 2)
poor response in African Americans
“Olols, alols, ilols”
Beta blockers
Alpha 1- Adrenergic Blockers
“zosin”
Block sympathetic receptors in arterioles causing vasodilatation
Alpha 1- Adrenergic Blockers adverse effects
bradycardia, bronchoconstriction, fatigue, activity intolerance, dizziness, nausea, decreased libido
Taper off to prevent rebound HTN
Alpha 1- Adrenergic Blockers nursing considerations
do not give within 4 hours of viagra
Alpha 2- Adrenergic Agonists action
decreases heart rate, BP & dilates arterioles
Alpha 2- Adrenergic Agonists adverse effects
sedation, dizziness, other CNS effects, nasal stuffiness
Vasodilators action
relaxes smooth muscles of blood vessels
Vasodilatation drops BP & increases water & sodium retention (leading to peripheral edema)
Vasodilators side effects
reflex tachycardia, sodium & water retention, dizziness, palpitations, CVA, BP hypotension
Calcium Channel Blockers “pine” uses
Used to treat HTN, Angina pectoris, dysrhythmias
Calcium Channel Blockers “pine” action
inhibit Ca+ from entering cell, limiting muscular contraction
Relax arterial smooth muscle, ↓ peripheral resistance,
↓ BP
↓ automaticity in the SA node & slows myocardial (AV) conduction velocity
↓ heart rate & prolongs refractory period
Calcium Channel Blockers “pine” indications
safe & well tolerated
Not used as monotherapy
Useful for elderly & African American
ACE Inhibitors considerations
if tx is not working, check kidney function
