Antihypertensives

Question 1

What does cardiac output depend on?

Answer 1

Venous return (venous tone, blood volume)
Heart rate
Contractility

Question 2

What does total peripheral resistance?

Answer 2

Resistance vessel diameter

Arterial tone

Question 3

What are OTC and prescription drugs that can cause hypertension?

Answer 3

Estrogens (oral contraceptives)
NSAIDs (nonsteroidal anti-inflammatory drugs)
Antidepressants, cyclosporin, amphetamines (stimulants)
Decreased compliance

Question 4

What are other conditions that can cause hypertension?

Answer 4

Renal artery stenosis (renovascular hypertension)
Coarctation of the aorta
Phaeochromocytoma (catecholamine secreting tumor)
Primary hyperaldosteronism

Question 5

What are three major compensatory responses to a decrease in blood pressure of the cause?

Answer 5

Hypovolemia (hemorrhage, dehydration)
Postural
Heart failure
Antihypertensive
Etc.

Question 6

What are non pharmacological treatments for hypertension?

Answer 6

Sodium restriction
Weight loss
Exercise
Limit alcohol (up to two drinks a day can be beneficial)
Smoking cessation
Relaxation

Question 7

What are pharmacological treatment options for hypertension?

Answer 7

First line agents:
- diuretics
-ACEi and ARBs
-CCBs
-Beta adrenergic receptora antagonist (but not in uncomplicated hypertension)
Other:
-alpha 1 adrenergic antagonist
-alpha 2 adrenergic agonists
-vasodilators

Question 8

What is uncomplicated hypertension?

Answer 8

When no other disease or risk factors are present

Question 9

What are lifestyle recommendations for hypertension?

Answer 9

Healthy diet: high in fresh fruits, vegetables and low fat dairy products, low in saturated fats, and salts in accordance with Canada’s Food Guide
Regular physical activity: optimum is 45-60 minutes of moderate cardiorespiratory activity 4-5 times a week
Weight loss (over 5 kg in those who are overweight)
Reduction of alcohol consumption
Relaxation
Smoke free environment

Question 10

Why are thiazides first line treatment options for hypertension?

Answer 10

They can potentiate other antihypertensives

May lower BP at doses that don’t perceivably alter urine flow

Question 11

Are loop diuretics good options for the treatment of hypertension?

Answer 11

They are not great for long term treatment
They are weaker antihypertensives
They can cause extreme electrolyte imbalances

Question 12

Are ACEi and ARBs good options for the treatment of hypertension?

Answer 12

They are first line single therapy in uncomplicated hypertension
They are recommended if concurrent condition (heart failure, left ventricle dysfunction, post-MI, diabetes, systolic dysfunction, proteinuria)
It is suggested that these agents may have benefits in addition to their blood pressure lowering

Question 13

What are propranolol and metoprolol?

Answer 13

Beta-adrenergic receptor antagonists

Question 14

What is the mechanism of beta blockers?

Answer 14

It’s unknown, but they work to lower blood pressure

Question 15

Are beta blockers effective as single therapy?

Answer 15

It was thought so until recently
There may be no improvements or it might even make things worse (increased incidence of type II diabetes)
It’s unclear if it decreases cardiovascular mortality
It’s good as a second drug to block the reflex activation of the heart by the SNS

Question 16

What are the problems with beta blockers?

Answer 16

Not metabolically neutral (may increase triglycerides and decrease HDL)
Avoid sudden withdrawal
Increased incidence of erectile dysfunction
Increased incidence of type II diabetes
Doesn’t protect against stroke

Question 17

When should beta blockers be avoided?

Answer 17

Asthma, COPD, peripheral vascular disease, insulin dependent diabetes (use with caution), physically active (?)

Question 18

When are beta blockers good?

Answer 18

Glaucoma, supraventricular arrhythmia, heart failure (always?), MI, angina
Everyone who is post-MI should be on a beta blocker
Sometimes these benefits override the risks above (may be used in an asthma who is post-MI or has heart failure)

Question 19

What is prazosin? What does it do?

Answer 19

Alpha1-adrenergic receptor antagonist
Not effective as single agent for chronic BP lowering (vasodilators arteries and veins)
Decreases insulin resistance (good)
Useful in BPH
Shown to decrease nightmares in PTSD

Question 20

What are the problems with prazosin?

Answer 20

Fluid retention with long-term treatment (give with diuretic)
First dose effect (initial large decrease in BP)
Orthostatic hypotension

Question 21

What is clonidine? What does it do?

Answer 21

Alpha2-adrenergic receptor agonist
Acts on central vasomotor centres
Decreases sympathetic nerve activity from CNS
Autonomic system remains intact (reflexes intact; orthostasis is rare)
It’s given as two unequal doses (high dose at night)
Limited use (sedation and dry mouth)
Rebound hypertension upon rapid cessation of the drug
More common as adjunct to general anesthetic

Question 22

Are vasodilators used for the treatment of hypertension?

Answer 22

They are not used alone for chronic blood pressure lowering

Question 23

What is hydralazine? What does it do?

Answer 23

It’s a vasodilator
It has a greater arteriolar effect
It’s given with beta blockers and diuretics
It’s used in pregnancy

Question 24

What are the problems with hydralazine?

Answer 24

May cause lupus like symptoms
May increase SNS activity (myocardial stimulation)
Headach, flushing nausea, hypotension, tachycardia, angina pectoris

Question 25

What is minoxidil? What does it do?

Answer 25

Arteriolar dilator
Give with a beta blocker and diuretic
Given for severe hypertension (refractory)
May cause pericardial effusion
Hirsutism
Similar problems to hydralazine