Pharm: antihypertensive therapy

Question 1

Name the 3 elements contributing to blood pressure that are affected by α1-adrenergic blockers.

Answer 1

1. Venous tone,
2. circulating regulators,
3. direct innervation

Question 2

Name the 2 elements contributing to bp that are affected by central α2-adrenergic agonists.

Answer 2

1. Circulating regulators

2. direct innervation

Question 3

List the 3 parts of the heart that are affected by norepinephrine stimulation of β-adrenergic receptors.

Answer 3

1. SA node to increase heart rate,
2. AV node to increase conduction velocity,
3. Myocardium to increase force of contraction

Question 4

What are the 3 effects of using beta blockers on the heart?

Answer 4

1. Decreased HR
2. Decreased contractility
3. Decreased renin release (downstream affect)

Question 5

Name the 3 populations in which use of metoprolol and atenolol is helpful.

Answer 5

1. diabetics,
2. asthmatics,
3. peripheral vascular disease

(cardio selective drugs)

Question 6

List 2 populations for which pindolol, acebutolol, and penbutolol are beneficial.

Answer 6

1. Bradyarrythmias

2. Peripheral vascular disease

Question 7

Explain 3 ways in which ARBs decrease bp.

Answer 7

1. Inhibits angiotensin-II receptors (AT1 only)
2. Decrease aldosterone levels
3. Decrease plasma volume and total peripheral resistance

(Unlike with ACEIs, dry cough and angioedema are not common side effects of ARBs)

Question 8

Predict 3 actions of calcium channel blockers (CCBs) based on the 3 sites of their action in the heart.

Answer 8

1. Vasodilation (dihydropyridines) and  total peripheral vascular resistance
2. decreased cardiac contractility (verapamil & diltiazem)
3. Slows AV nodal conduction (verapamil & diltiazem)

Question 9

Which two CCBs are more cardio-selective?

Answer 9

1. Verapamil

2. Diltiazem

Question 10

How do alpha blockers treat high blood pressure and which are used for:

1. pheochromocytoma
2. clonidine withdrawal
3. severe postural hypertension

Answer 10

Relax vascular smooth muscle by blocking NE from binding alpha-1 receptors.

1. Phenoxybenzamine, Phentolamine
2. Phentolamine, Propranolol
3. Prazosin

Question 11

Describe the organ upon which α-methyldopa acts to decrease bp and what mediates this effect.

Answer 11

Taken up by adrenergic nerve terminals and converted to α-methylnorepinephrine in the CNS where α2 receptors are stimulated to decrease sympathetic out flow to the periphery which then lowers bp by reducing TPR.

Question 12

Main population where α-methyldopa is the drug of choice for HTN.

Answer 12

Pregnant Women

Question 13

Name the advantage of nadolol, carteolol, betaxalol, and bisoprolol over other β blockers.

Answer 13

Long half-lives so can be administered once daily

Question 14

Name the single indication for esmolol and why.

Answer 14

It is used for management of intraoperative and postoperative hypertension, and sometimes for hypertensive emergencies, particularly when hypertension is associated with tachycardia. It has a short half-life.

Question 15

List the two populations for which ACE inhibitors are the preferred antihypertensive agent.

Answer 15

1. (Young) white or Asian hypertensive patients

2. Patients with high plasma renin activity

Question 16

Name the site of action for hydralazine.

Answer 16

Has a direct vasodilator action on vascular smooth muscles. Works mainly on arterioles, not veins.

Question 17

Explain the site and mechanism of minoxidil’s action.

Answer 17

Pro-drug that works via a sulfate metabolite, which activates K+ channels and relaxes vascular smooth muscles.

Question 18

Main side effects of minoxidil.

Answer 18

hirsutism and coarseness of facial features

Question 19

Why does cocaine inhibit the effects of guanethidine?

Answer 19

It uses the NE-reuptake transporter to get into presynaptic neurons. Cocaine blocks this.

Question 20

Explain why vasodilators such as hydralazine may require other agents to effectively reduce blood pressure.

Answer 20

Vasodilators such as hydralazine cause a significant decrease in peripheral vascular resistance, but evoke a strong compensatory tachycardia and salt and water retention that is capable of almost completely reversing their effect. The addition of a β-blocker prevents the tachycardia; addition of a diuretic (e.g. hydrochlorothiazide) prevents the salt and water retention.

Question 21

What is resistant hypertension ?

Answer 21

Patients that do not respond to hypertensive therapy even if multiple drugs are given.