LEC - 7.3 - Vasodilators

Question 1

Reduce systolic and diastolic blood pressure by direct relaxation of vascular smooth muscle, thus lowering peripheral vascular resistance.

Answer 1

Vasodilators

Question 2

Uses of vasodilators:

Answer 2

Moderate hypertension when 1st line fails – with beta blockers and diuretics

Reserved for severe hypertension or hypertensive emergencies

Question 3

Examples of Vasodilators:

Answer 3

Nitroprusside
Hydralazine

Question 4

Indications for Nitroprusside:

Answer 4

Severe hypertension, maintenance of controlled hypotension during anesthesia, acute heart failure

Question 5

Actions of Nitroprusside:

Administrations:

Adverse effects:

Onset of action:

Answer 5

Acts directly on vascular smooth muscle to cause vasodilation and drop of blood pressure. It does not inhibit cardiovascular reflexes and tachycardia; renin release will occur

Used intravenously

Apprehension, headache, palpitations, cyanide toxicity, diaphoresis, nausea, vomiting, abdominal pain, irritation at the injection site

for IV route is 1-2 minutes

Question 6

Nursing Implementation for Nitroprusside

Answer 6

Encourage the patient to implement lifestyle changes, including weight loss, smoking cessation, decreased alcohol and salt in the diet, and increased exercise, to increase the effectiveness of antihypertensive therapy.

Monitor blood pressure closely during administration to evaluate for effectiveness and to ensure quick response if blood pressure falls rapidly or too much.

Monitor blood glucose and serum electrolytes to avoid potentially serious adverse effects.

Monitor the patient carefully in any situation that might lead to a drop in fluid volume (e.g., excessive sweating, vomiting, diarrhea, dehydration) to detect and treat excessive hypotension that may occur.

Provide comfort measures to help the patient tolerate drug effects, including small, frequent meals; access to bathroom facilities; safety precautions if CNS effects occur; environmental controls; appropriate skin care as needed; and analgesics as needed.

Question 7

Hydralazine is used in:

Answer 7

Fall in BP is caused by stimulation of adrenergic system leading to:
Cardiac stimulation producing palpitation and rise in CO preventing– anginal attack
Tachycardia
Increased Renin secretion – Na+ retention

Question 8

The effects of Hydralazine are countered by administration of ___ and ___

Answer 8

beta blockers and diuretics

Question 9

A powerful vasodilator and has 2 major uses – antihypertensive and alopecia
Rarely indicated in hypertension especially in life threatening ones
More often in alopecia to promote hair growth

Answer 9

Minoxidil

Question 10

2 major uses of Minoxidil

Answer 10

antihypertensive and alopecia

Question 11

Mechanism of action of hair growth:

Answer 11

Enhanced microcirculation around hair follicles and also by direct stimulation of follicles
Orally not used any more
Topically as 2-5% lotion/gel and takes months to get effects

Question 12

are medicines that lower heart rate and reduce blood pressure. They block the signals from the brain to the nervous system that increase the heart rate and narrow blood vessels. As a result, the heart does not pump as hard. Blood flows more easily through the body’s veins and arteries.

Answer 12

Centrally Acting Drugs

Question 13

Examples of Centrally-acting Drugs:

Answer 13

Alpha-Methyldopa
Clonidine

Question 14

a pro drug

Answer 14

Alpha-Methyldopa

Question 15

Mechanism of Action of Alpha-Methyldopa:

Answer 15

Converted to alpha methyl noradrenaline which acts on alpha-2 receptors in brain and causes inhibition of adrenergic discharge in medulla causing a fall in BP

Question 16

Adverse effects of Alpha-Methyldopa

Answer 16

cognitive impairment, postural hypotension, positive Coomb`s test

Question 17

Alpha-Methyldopa is not used therapeutically except in hypertension during pregnancy

Answer 17

NA

Question 18

Imidazoline derivative, partial agonist of central alpha-2 receptor

Not frequently used because of tolerance and withdrawal hypertension

Answer 18

Clonidine

Question 19

Indicated for the treatment of edema associated with congestive heart failure, acute pulmonary edema, liver disease (including cirrhosis), renal disease, and for the treatment of hypertension.

Answer 19

Diuretic Drugs

Question 20

Diuretics are popular because they work quite well, are quite safe, well tolerated, and are not very expensive.

Answer 20

NA

Question 21

Examples of Diuretics:

Answer 21

Thiazide and Thiazide- Like Diuretics
Loop Diuretics or “Potassium Wasting Diuretics”
Potassium Sparing Diuretics
Carbonic Anhydrase

Question 22

___ are considered to be mild diuretics

Answer 22

Thiazide

Question 23

___ are sulfa-based medications and a client with a sulfa allergy is at risk for allergic reactions.

Answer 23

Hydrochlorothiazide

Question 24

___ act directly to dilate the smooth muscles in the arterioles. Because the arterioles are made larger, the heart does not have to pump so hard to get blood into them. This helps keep the blood pressure down.

Answer 24

Thiazides

Question 25

Examples of Loop Diuretics or “Potassium Wasting Diuretics”

Answer 25

bumetamide (Burinex)
furosemide (Lasix)

Question 26

Act by blocking active transport of chloride, sodium, and potassium in the thick ascending loop of Henle

Answer 26

Loop Diuretics or “Potassium Wasting Diuretics”

Question 27

Often used in patients with kidney disease, CHF, and cirrhosis of the liver.

Answer 27

Loop Diuretics or “Potassium Wasting Diuretics”

Question 28

Potassium Wasting Diuretics Side Effects:

Answer 28

Fatigue
Anorexia
Vomiting
Nausea
Muscle weakness
Leg cramps
Paresthesias
Decreased bowel motility

Question 29

Examples of Potassium Sparing Diuretics

Answer 29

spironolactone (Aldactone)
triamterene (Dyrenium)
amiloride (Midamor)

Question 30

Used for patients in whom a high risk of hypokalemia associated with diuretic use exists

Answer 30

Potassium Sparing Diuretics

Question 31

Adverse effects of Potassium Sparing Diuretics:

Answer 31

hyperkalemia which can cause lethargy, confusion, ataxia, muscle cramps, and cardiac arrhythmias

Question 32

Potassium sparing diuretics increase the excretion of water and sodium but save potassium.

Answer 32

NA

Question 33

Examples of Carbonic Anhydrase

Answer 33

acetazolamide (Diamox)
Methazolamide

Question 34

Relatively mild diuretics used to treat glaucoma because the inhibition of carbonic anhydrase results in ___

Answer 34

decreased secretion of aqueous humor of the eye

Question 35

Adverse effects of Carbonic Anhydrase:

Answer 35

acid-base disturbances and electrolyte balance

Question 36

The most common and potentially dangerous adverse effect related to an osmotic diuretic is the sudden drop in fluid levels

Answer 36

Osmotic Diuretic

Question 37

Nausea, vomiting, hypotension, lightheadedness, confusion, and headache can be accompanied by cardiac decompensation and even shock

Answer 37

NA

Question 38

Patients receiving mannitol should be closely monitored

Answer 38

NA

Question 39

Examples of Osmotic Diuretics:

Answer 39

Mannitol (Osmitrol)

Question 40

Route of administration for osmotic diuretics

Answer 40

Available only for intravenous use

Question 41

Used in the prevention and treatment of acute renal failure
Reduction of intracranial pressure
Treatment of cerebral edema

Answer 41

Osmotic Diuretics

Question 42

Nursing Implementation for Diuretic Drugs

Answer 42

Administer oral drug with food or milk

Administer IV diuretics slowly

Continuously monitor urinary output, cardiac response, and heart rhythm of patients receiving IV diuretics

Administer oral from early in the day

Monitor the dose carefully and reduce the dose of one or both drugs if given with antihypertensive

Monitor the patient response to the drug

Assess weight daily

Check skin turgor

Provide comfort measures, including skin care and nutrition consultation