Antihypertensive Drugs - Ch 21, 47-50 Flashcards
What are 90% of hypertension cases?
Unknown cause (idiopathic)
Aka Essential or primary hypertension
What are 10% of hypertension cases?
Known cause
-Secondary hypertension
What can hypertension lead to?
Cerebrovascular disease
Hypertensive retinopathy
Left ventricular dysfunction
Left ventricular hypertrophy
Coronary artery disease
Chronic kidney disease
Peripheral artery disease
What are some benefits of treating hypertension?
Decreased heart failure by 50%
Decreased stroke by 38%
Decreased heart attack by 15%
Decreased death ny 10%
What are some lifestyle considerations that contribute to hypertension?
Obesity
Physical exercise
Salt intake
Increase potassium intake
Dietary habits including fat intake
Alcohol
Smoking
What blood pressure needs hypertension treatment in the general population?
<140/90
What blood pressure needs hypertension treatment in high risk populations (e.g, CV disease, Non-DM CKD)?
≤120/NA
What blood pressure needs hypertension treatment in diabetics?
<130/80
What are the categories of antihypertensive drugs?
Angiotensin converting enzyme (ACE) inhibitors
Angiotensin II receptor blockers (ARBs)
Calcium channel blockers (CCBs)
Diuretics
B-adrenoreceptor blockers
Vasodilators
Adrenergic agents
What are ACE inhibitors?
Large grouo of safe and effective drugs
Often used as first-line agents in heart failure and hypertension
What are ACE inhibiotrs often combined with?
Thiazide diuretic or calcium channel blocker
Examples of ACE inhibitors?
Captopril (Capoten)
Enalapril (Vasotec)
Lisinopril and quinapril
What is unique about Captopril?
Shortest half-life of the prils
How is Enalapril (Vasotec) administered?
Oral
Parenteral
What is unique about lisinopril and quinapril?
Newer agents, long half lives, once-aday administration
Why would patients with diabetes and hypertension want to use ACEIs?
ACEIS have renal protective effects in diabetics
Why are ACEIs used to treat heart failure?
Slows progression of left ventricular remodelling after an MI
What is the mechanism of action of ACEIs?
- Prevents angitensin II vasoconstriction, which reduces peripheral resistance (afterload)
-Prevents aldosterone release, which reduces salt and water reabsorption
-Prevents the breakdown of bradykinin
What adverse effects are associated with ACEIs?
Dry, nonproductive cough
First-dose hypotensive effect may occur
Possible hyperkalemia
What drugs do ACE inhibitors have interactions with?
Potassium (K) supplements and K-sparing diuretics
When is ACEIs use contraindicated?
Pregnancy
ARBs are similar to ACEIs, but not identical, what are some differences?
Don’t cause a dry cough
-Not combined with ACEIs normally
Examples of ARBs?
Losartan (cozaar)
Valsartan (Diovan)
What is the mechanism of action of ARBs?
Angiotensin II receptor antagonist
-Block receptors that Ang II activates
What are the effects of ARBs when they block receptors than Ang II activates?
Blocks Ang-II mediated vasoconstriction
Blocks release of aldosterone
ARBs may be used alone, or with what other agents?
CCB
Diuretics
Angiotensin II receptor blockers (ARBs) are alternatives to what?
ACE inhibitors
When is ARB use contraindicated?
Pregnancy
What are calcium channel blockers used for?
Hypertension
Angina
Dysrhythmias
What are the kinds of calcium channel blockers?
Benzothiazepines (cardciac + vascular)
Phenylalkamines (cardiac + vascular)
Dihydropyridines - DHPs (vascular selective)
Examples of Benzothiazepines?
Diltiazem (Cardizem)
Example of Phenylalkamines?
Verapamil
Examples of Dihydropyridines - DHPs?
Amlodipine, nifedipine, nimodipine
What is the effect of CCBs on cardiac muscle?
Block cardiac muscle Ca channels which alters electrical activity of cardiac muscle (SA, AV nodes and muscle)
What is the effect of CCBs on vascular muscle?
Inhibits Ca entry into arteriolar vascular smooth muscle cells which causes relaxation and decreased peripheral resistance (lowers BP)
Adverse effects: CCBs - Verapamil/Diltiazem?
Cardiovascular: Hypotension, dizziness, flushing, peripheral edema
Gastrointestinal: Constipation, nausea
Other: Rash, demititis
Adverse effects: CCBs - DHPs?
Cardiovascualr: Hypotension, dizziness, palpitations, tachycardia, flushing, peripheral edema
Gastrointestinal: Little constipation
Other: Rash, demititis
What is the mechanism of action of thiazide diuretics for hypertension treatment?
Decrease the plasma and extracellular fluid volumes which decreases preload and cardiac output, and decreases total peripheral resistance
Decreased herat workload = decreased BP
What is the first line drug in guidelines for hypertension?
Diuretics
Examples of thiazides/thiazide-like diurteics?
Hydrochlorothiazide (hyrodiuril)
Chlorthalidone (thiazide-like) -longer acting
What can thiazide use possibly lead to?
Hypokalemia
Digoxin interation
What kind of diuretics are preferred for HTN?
Longer acting over short acting
Examples of longer-acting (thiazide-like) diuretics?
Clorthalidone, indapamide
Examples of shorter-acting (thiazide) diuretics?
Hydrochlorothiazide
What are some reccomended sungle pill combinations used to treat HTN?
ACEI + CCB
ACEI + diuretic
ARB + diuretic
ARB + CCB
What are the 4 adrenoceptors subtypes?
α1
α2
β1
β2
What are β-adrenoreceptor blockers?
β-adrenoreptor antagonists, β1-blockade
Act in the periphery, mainly heart
Block norepinephine/epinephrine action in heart
What do beta-blockers reduce?
↓Heart rate
↓Force of heart muscle contraction
↓Stroke volume
Examples of β-adrenoreceptor blockers?
Metoprolol (Lopressor)
Atenolol
Propanolol (Inderal)
What kind of β-adrenoreceptor blockers are β1- selective?
Metoprolol
Atenolol
What kind of β-adrenoreceptor blockers are non-selective?
Propanolol
What are β-adrenoreceptor blockers used for?
Hypertension
Heart failure
Angina
Dysrhythmias
What do β-adrenoreceptor blockers cause an intolerance to?
Excercise
Who should avoid using β-adrenoreceptor blockers ?
Asthma patients
What are dual α1 and β-receptor blockers?
Act in the periphery of heart and blood vesseels
Reduce heart rate
cause vasodilation
What adrenergic recpetor is blocked to cause reduced heart rate?
β1-receptors
What adrenergic receptor is blocked to cause vasodilation?
α1 receptors
Examples of dual α1 and β-receptor blockers?
Labetalol
Carvedilol
How do centrally acting α2 adrenoceptors interact with the body?
Agonists
How do peripherally acting α1 adrenoceptors interact with the body?
Antagonists
What do centrally acting α2-recepotor agonists do?
Stimulate α2-adrenergic receptors in the brainstem to reduce norepinephrine release,
decrease SNS outflow from CNS,
cause vasodilation (decrease BP)
Examples of centrally acting α2-recepotor agonists?
Clonidine (Catapres)
Methyldopa
What centrally acting α2-recepotor agonist is rarely used?
Clonidine (Catapres)
What is the 1st line therapy for hypertension in pregnancy?
Methyldopa
-Pro-drug
When are centrally acting α2-recepotor agonists usually used?
After other agents have failed or in combination with other drugs due to adverse effects
Adverse effects associated with centrally acting α2-recepotor agonists?
Sedation
Dry mouth
What do peripherally acting α1-recepotor antagonists do?
Block α1-adrenergic receptors
Block NE contraction of blood vessels
Examples of peripherally acting α1-recepotor antagonists?
Prazosin (minipres)
Doxazosin
Terazosin
Peripherally acting α1-recepotor antagonists provide relief of symptoms of what?
BPH - Benign prostatic hypertrophy
Peripherally acting α1-recepotor antagonists are used in combination with what to treat severe HF?
Cardiac glycosides and diuretics
what adverse effects are associated with α-receptor adrenergic agents?
Dry mouth
Sedation, drowsiness
Costipation
Headaches
Nausea
Cardiac disturbances (palpitations)
Sleep disturbances
rash
α-receptors have a high indicence of what?
Orthostatic hypotension
What is the mechanism of action of vasodilators?
Directly relax arteriolar smooth muscle (peripheral vasodilation)
What are vasodilators used for?
Hypertension
-Soemtimes in combination with other drugs
Examples of vasodilators?
Hydralazine (Apresoline)
diazoxide
minoxidil
Sodium nitroprusside (Nipride) (Nitirc oxide action)
What vasodilators are administed IV in hypertensive emergencies?
IV Sodium nitroprusside and diazoxide
What adverse effects are associated with hydralazine (vasodilator)?
Dizziness, headache, anxiety
Tachycardia
nausea and vomiting
diarrhea
anemia
dyspnea
edema
nasal congestion
What adverse effects are associated with sodium nitroprusside (vasodilator)?
Bradycardia
Hypotension
Possible cyanide toxicity
Why should antihypertensive drugs not be stopped abruptly?
May cause rebound hypertensive crisis and lead to stroke
What should the nurse teach the patient if they are using antihypertensive drugs?
Avoid smoking
Avoid eating foods high in sodium e.g, tinned osups, packaged meals
Change lifestyle
Change positions slowly
Avoid aggravating low BP
What aggravates low BP?
Hot tubs, showers, baths
Hot weather
Prolonged sitting or standing
Intense physical exercise
Alcohol ingestion
