Antihypertensive Drugs Flashcards
Types of hypertension
Unknown cause
- Essential, idiopathic, or primary hypertension
- 90% of cases
Known cause
- Secondary hypertension
- 10% of cases
Lifestyle implications
- Obesity
- Physical exercise
- Salt intake
- Increased potassium intake
- Dietary habits including fat intake
- Alcohol
- Smoking
BP Treatment Target
General population
- <140/90
High risk (CV, non-DM CKD) - < 120/NA
Diabetes
- <130/80
Categories for Antihypertensive Drugs
- Angiotensin converting enzyme (ACE) inhibitors
- Angiotensin II receptor blockers (ARBs)
- Calcium channel blockers (CCBs)
- Diuretics
- B-adrenoceptor blockers
- Vasodilators
- Adrenergic agents
ACE Inhibitors
- Captopril (Capoten)
- Shortest half-life of the “prils”
- Safe and effective drugs
- First-line agents for HF and hypertension
- Often combined with a thiazide diuretic or calcium channel blocker
Other meds
- enalapril (vasotec)
- lisinopril, and quinapril
ACE Inhibitors - Indications
Hypertension
- Drugs of choice for diabetic patients
HF (either alone or in combination with diuretics or other agents)
- Drug of choice in hypertensive clients with heart failure
Slows progression of left ventricular remodelling after MI
ACE Inhibitors - Mechanism of Action
- Prevents Ang II vasoconstriction (reduces peripheral resistance and afterload)
- Prevents aldosterone release (reduces salt and water reabsorption)
- Prevents the breakdown of bradykinin (therefore blood pressure continues to lower)
ACE Inhibitors - Adverse Effects
- Fatigue
- Headache
- Impaired taste
- Dizziness
- Mood changes
- Possible hyperkalemia
- Dry, nonproductive cough which reverses when therapy is stopped
First dose hypotensive effect may occur
ACE Inhibitors - Interactions
K supplements and K-sparing diuretics
When should you not use ACE Inhibitors?
In pregnancy
ARB - Drugs
*Losartan (Cozaar)
Valsartan (Diovan)
Generally not combined with ACEIs - similar in composition
ARB - Mechanism of Action
Block receptors that angiotensin II activates
- Blocks vasoconstriction and blocks release of aldosterone
ARB - Indicaitons
Hypertension
Adjunctive agent for HF treatment
May be used alone or with others like diuretics
Used mostly in clients who can’t tolerate ACE inhibitors
What should you not use ARB drugs?
In pregnancy
What can calcium channel blockers be used to treat?
*Hypertension
Angina
Dysrhythmias
What are 3 example of CCB’s?
Benzothiazepines (cardiac and vascular)
-*Diltiazem
Phenylalkylamines (cardiac and vascular)
- Verapamil
Dihydropyridines (vascular selective)
- Amlodipine
What effect do CCB’s have on cardiac muscles?
It alters electrical activity of cardiac muscle cells by blocking Ca channels
What effect do CCB’s have on vascular muscles?
It causes relaxation and decreased peripheral resistance (decreased blood pressure)
What are the 2 main adverse effects of Verapamil/Diltiazem?
- Cardiovascular
- Hypotension, flushing, peripheral edema - Gastrointestinal
- *Constipation, nausea
How does the DHP’s adverse effects differ from Verapamil/Diltiazem?
There is very little constipation, palpitations and tachycardia
How do Thiazide Diuretics influence the heart?
Decreases preload, cardiac output, and total peripheral resistance
Overall decreased workload for heart and decreased BP
What is an example of a Thiazide Diuretics?
Hydrochlorothiazide
What is a possible adverse effect of Thiazide Diuretics?
Hypokalemia
What are the 4 adrenoceptor subtypes?
a1
a2
B1
B2
