Pharmacology Lecture 3: Vasodilators and Hypertensive Drugs

Question 1

Functions of arterial vasodilators (3)

Answer 1

1. Preferntial relaxation of arterial smooth muscle
2. Reduce afterload (peripheral resistance)
3. Lack of venous dilation –> increased preload (VR)

Question 2

2 results of arterial vasodilator function

Answer 2

1. CO increases
2. BP lowers w/ resultant reflex increase in sympathetic tone, HR and SV

Question 3

3 general functions of venous vasodilators

Answer 3

1. Relax venous smooth muscle tone
2. Produce blood pooling in capacitance vessels
3. Preload reduction = decreased CO

Question 4

2 effects of vasodilators on coronary vascular

Answer 4

1. Dilatation of conductance vessels and collaterals increases flow to ischemic areas
2. May dilate coronary arteries (may steal blood from ischemic areas)

Question 5

Function of nitrates

Answer 5

Prodrugs –> lberate local nitric oxide –> vascular smooth muscle relaxation

Question 6

Effect of systemic venous capacitance vessel dilation

Answer 6

Reduce preload –> reduced LV wall tension –> decreased myocardial O2 requirements

Question 7

Nitrate absorption by different modes of administratoin

Answer 7

Oral = prominent “first pass” effect (limited bioavailability)

Patch = well-absorbed by skin and mucous membranes

Question 8

4 clinical uses for nitrates

Answer 8

1. Treatment of angina pectoris
2. Preservation of myocardium after MI
3. Controlled hypotension
4. Heart failure

Question 9

4 adverse effects of nitrates

Answer 9

1. Headache
2. Palpitations
3. Flushing
4. Syncope

Question 10

3 arteriolar vasodilators

Answer 10

1. Hydralazine
2. Minoxidil
3. Diazoxide

Question 11

Hydralazine, minoxidil and diazoxide effect

Answer 11

Lower blood pressure

Question 12

Potential consequences of using arteriolar vasodilators

Answer 12

• Increased proximal tubular sodium reabsorption = antagonize BP lowering effect (salt and water retention)
• Headaches and palpitations

Question 13

Additional medication added to arteriolar vasodilators in order to counteract side effects

Answer 13

• Beta blocker
• Diuretic

Question 14

Define prazosin

Answer 14

Alpha 1 adrenergic receptor blocker (mixed venous and arteriolar effects)

Question 15

3 uses for prazosin

Answer 15

• Hypertension treatment
• Heart failure
• BPH obstructive symptoms (increase tone of smooth muscle of bladder neck)

Question 16

Vascular effects of calcium channel blockers

Answer 16

Impair excitation-contraction couplign in cardiac and vascular smooth muscle = dilate coronary arteries and peripheral arterioles + decrease cardiac contractility

Question 17

3 uses for calcium channel blockers

Answer 17

1. Coronary artery disease
2. Hypertension
3. Supraventricular tachydysrhythmias

Question 18

List 3 calcium channel blockers in order of more vascular to more electrophysiological properties (2nd one is intermediate properties)

Answer 18

1. Nifedipine
2. Diltiazem
3. Verapamil

Question 19

Function of ACE inhibitors

Answer 19

Inhibit conversion of angiotensin-1 to angiotensin-2

Question 20

2 uses of ACE inhibitors

Answer 20

• Hypertension treatment (lower systemic BP)
• Heart failure

Question 21

3 adverse effects of ACE inhibitors

Answer 21

1. Hypotension
2. Cough
3. Taste disturbance

Question 22

Uses of angiotensin 2 receptor blockers

Answer 22

• Hypertension
• Heart failure

Question 23

Effects of angiotensin 2 receptor blockers

Answer 23

Same as ACE inhibitor side effects (minus cough):

• Hypotension
• Taste disturbance