Vasodilators

Question 1

Nitroglycerin: Class

Answer 1

Peripheral Vasodilator

venous dilation > arterial dilation

Question 2

Nitroglycerin: Use

Answer 2

Myocardial Ischemia
Coronary Vasospasm
HTN
Ventricular failure
Controlled Hypotension

Question 3

Nitroglycerin: Mechanism of Action

Answer 3

As Nitroglycerin is metabolized, releases nitric oxide and cyanide.
Nitric oxide activates guanylyl cyclase which synthesizes cGMP, decreases intracellular Calcium. -> Smooth muscle dilation

Question 4

Nitroglycerin: Dose

Answer 4

IV Infusion: 5 - 100 mcg/min
SL: 0.4 mg

Question 5

Nitroglycerin: Pharmacokinetics

Answer 5

Absorption: IV, SL, Transdermal

Onset: 2 minutes
Duration of Action: 5 minutes

Metabolism: Rapid reductive hydrolysis in the liver and blood by glutathione-organic nitrate reductase

Elimination: Renal

Question 6

Nitroglycerin: Contraindictions

Answer 6

Patients with:
Aortic Stenosis
Hypertrophic cardiomyopathy
Increased ICP
Hypotension
Heart Failure

Question 7

Nitroglycerin: Considerations

Answer 7

Nitrate byproduct can convert hemoglobin to methemoglobin
Headache
Tachycardia
Tolerance can develop with prolonged use

Question 8

Nitroprusside: Class

Answer 8

Direct peripheral arterial vasodilator
relaxes both arterial and venous smooth muscle

Question 9

Nitroprusside: Use

Answer 9

Antihypertensive

Question 10

Nitroprusside: Mechanism of Action

Answer 10

Nitroprusside is metabolized into nitric oxide and cyanide.
Nitric Oxide activates guanylyl cyclase which synthesizes cGMP, decreases intracellular calcium, which causes smooth muscle dilation

Question 11

Nitroprusside: Dose

Answer 11

Infusion: 0.3 - 10 mcg/kg/min

Question 12

Nitroprusside: Pharmacokinetics

Answer 12

Absorption: IV

Onset: 1 minute
Duration of Action: 3 - 5 minutes

Metabolism: Iron electron of oxyhemoglobin binds to NTP. Gets broken down into cyanmethemoglobin and cyanide

Elimination: Renal

Question 13

Nitroprusside: Contraindications

Answer 13

Aortic Stenosis
Hypertrophic Cardiomyopathy
Increased ICP
Renal Failure (build up Thiocyanate)

Question 14

Nitroprusside: Considerations

Answer 14

Can cause tachycardia, headache, and bronchodilation
Risk for Intracoronary steal
Risk for Cyanide Toxicity
May decrease lung perfusion
Need to protect from light

Question 15

Hydralazine: Class

Answer 15

Direct acting Arterial vasodilator

Question 16

Hydralazine: Use

Answer 16

Treat HTN

Question 17

Hydralazine: Mechanism of Action

Answer 17

Activate guanylate cyclase to increase cGMP

Question 18

Hydralazine: Dose

Answer 18

Bolus: 2.5 - 20 mg

Question 19

Hydralazine: Pharmacokinetics

Answer 19

Absorption: IV, PO

Onset: 15 minutes
Duration of Action: 2 - 4 hours

Metabolism: Hepatic

Elimination: Renal

Question 20

Hydralazine: Contraindications

Answer 20

Patients with:
Aortic stenosis
Hypertrophic cardiomyopathy
increased ICP
Hypotension
Heart Failure

Question 21

Hydralazine: Considerations

Answer 21

Can cause reflex tachycardia

Question 22

Nicardipine: Class

Answer 22

Calcium Channel Blocker

Question 23

Nicardipine: Use

Answer 23

Treatment of:
Angina
HTN
Cerebral Vasospasm
Controlled Hypotension

Question 24

Nicardipine: Mechanism of Action

Answer 24

Depress electrical impulses in the SA and AV nodes by blocking the influx of Calcium ions

Question 25

Nicardipine: Dose

Answer 25

Infusion:
5 mg/hr increase by 2.5mg q 15 minutes.
MAX dose 15 mg/hr

Question 26

Nicardipine: Pharmacokinetics

Answer 26

Absorption: IV

Onset: 1 minute
Duration of Action: 3 hours

Metabolism: Hepatic

Elimination: Renal

Question 27

Nicardipine: Contraindications

Answer 27

Acute MI
Heart Failure
Bradycardia
Hypotension
Patient taking Dantrolene

Question 28

Nicardipine: Considerations

Answer 28

May cause reflex tachycardia