Lesson C3 - Antihypertensive Drugs

Question 1

hypertension

Answer 1

high blood pressure

Question 2

lowering of high blood pressure would

Answer 2

lower the possibility of

stroke, heart attack, heart failure and kidney damage.

Question 3

what is high blood pressure?

Answer 3

The heart is a muscular pump providing pressure for blood to circulate through blood vessels,
allowing blood to provide nutrients and oxygen to all organs. The blood pressure must be kept
within relatively narrow limits and the body has several mechanisms to achieve control of blood
pressure.

Question 4

Hypertensaion leads to:

Answer 4

increased vascular disease, increase in heart attacks, increase in stroke and an increase in renal
disease

Question 5

When an individual has a basal diastolic pressure of 90-105 millimetres of mercury and no
detectable kidney, heart or brain problems, she/he is classified as having

Answer 5

mild hypertension

Question 6

An individual with a basal diastolic pressure of greater than 130 millimetres of mercury is
classified as having

Answer 6

severe hypertension

Question 7

An individual with blood pressure intermediate in

severity between mild and severe is classified as having

Answer 7

moderate hypertension.

Question 8

why should high blood pressure be controlled?

Answer 8

The reason high blood pressure should be controlled is that when blood pressure is above normal
for long periods, the possibility of stroke, heart attack, heart failure, and kidney damage is
increased

Question 9

One way of controlling blood pressure is by instituting

Answer 9

lifestyle changes

Question 10

It has been clearly
documented that the following lifestyle changes will lower blood pressure: (a) reducing weight,
(b) regular exercise, (c) low salt diet, and (d)

Answer 10

reduced alcohol consumption

Question 11

How do drugs lower blood pressure?

Answer 11

(a) By dilating (increasing the diameter) of blood vessels, (b) by reducing the force of the heart
beat, and (c) by increasing the removal of salt and water from the body.

Question 12

What factors control blood pressure?

Answer 12

There are three factors which control blood pressure: (1) volume of fluid in blood vessels, (2)
resistance to blood flow in the circulation, and (3) the renin-angiotensin-aldosterone system.

Question 13

Volume of fluid in blood vessels:

Answer 13

Increasing the volume of fluid in the blood vessels increases blood pressure, while decreasing the
volume of fluid in blood vessels leads to a decrease in blood pressure. The volume of fluid in the
blood vessels is controlled primarily by the kidney.

Question 14

Resistance to blood flow in the circulation:

Answer 14

diminished SNS activity will result in
diminished release of noradrenaline, resulting in dilation of arterioles and reduced resistance to
blood flow.

Question 15

Renin-angiotensin-aldosterone system:

Answer 15

Renin, an enzyme released from the kidney, acts upon a protein present in blood, namely α2-globulin. A small portion of the protein is split off and this small portion is a peptide named
angiotensin I. An enzyme known as angiotensin converting enzyme (abbreviated as
ACE) acts upon angiotensin I, reducing it in size to form the peptide, angiotensin II.
Angiotensin II acts upon blood vessels to cause vasoconstriction and results in elevation of blood
pressure. In addition, angiotensin II acts upon the adrenal cortex, a portion of an organ situated
on top of the kidney, causing the liberation from the adrenal cortex of a hormone known as
aldosterone. Aldosterone acts upon specific aldosterone receptors in a portion of the kidney to
cause increased retention of sodium and water by the kidney. The retention of sodium and water
by the kidney in turn leads to an elevation of blood pressure.

Question 16

Pharmacological Agents for Treatment of Hypertension

Answer 16

Diuretics, Drugs which decrease sympathetic nervous system activity, Vasodilators – Angiotensin converting enzyme (ACE) inhibitor – captopril, Calcium channel blocker – nifedipine

Question 17

For therapy of hypertensive patients with no co-existing medical conditions or organ damage:

Answer 17

▸ Start therapy with either a low-dose diuretic or a beta blocker. If there are adverse
effects or an inadequate response, try the other.

▸ If response is only partial, use a combination of a diuretic and a beta blocker, or
monotherapy with an alpha blocker, ACE inhibitor, calcium channel blocker, or
centrally-acting drug

Question 18

Diuretics – thiazide diuretics:

Answer 18

They are efficacious when used alone and

enhance the efficacy of most other antihypertensives when given concurrently

Question 19

Beta-adrenergic blocking drugs – propranolol:

Answer 19

These drugs are widely used because hypertension clinical trials show a reduction in stroke and other serious cardiovascular problems.

Question 20

Angiotensin converting enzyme (ACE) inhibitors – captopril:

Answer 20

One of the advantages of this group of antihypertensive agents is that they are not thought to
cause sexual dysfunction, a problem seen with other antihypertensives. They can be used in
asthma. They do not cause an alteration in carbohydrate metabolism or plasma concentration of
lipoproteins and can therefore be used in diabetes. There is some preliminary evidence that ACE
inhibitors will reduce the incidence of heart disease in patients with high blood pressure more
effectively than other blood pressure lowering drugs.