D.5 Delivery of nitrates by buccal and transdermal route

Question 1

What are nitrates used to treat?

Answer 1

Symptoms of angina

Question 2

What three ways can nitrates be used to treat angina ?

Answer 2

To relieve an attack that is occuring by using the medicine when the attack begins

To prevent attacks from occuring by using the medicine just before an attack is expected to occur

To reduce the number of attacks that occur by using the medicine regularly on a long-term basis

Question 3

What are organic nitrates?

Answer 3

Potent vasodilators

Question 4

How would you synthesis glyceryl trinitrate (GTN)?

Answer 4

Glycerol + HNO3 —-> GTN

Isosrobid + HNO3 —-> Isosorbid dinitrate

Question 5

Why is there an explostion when high pressure is applied to glycerin trinitrate?

Answer 5

Massive increase of gas which leads to an explusion

Question 6

True/false? Organic nitrates require enzymic processes to for NO?

Answer 6

True

Question 7

What is activated when NO is released in smooth muscle ?

Answer 7

Guanylyl cyclase which increases cGMP levels

This causes the relaxation of smooth muscles

Question 8

What are the effects of nitrovasodilators ?

Answer 8

• Direct relaxant effect on vascular smooth muscle and the dilation of coronary vessels which imporve the oxygen supply to the myocardium (heart).
• The dilation of peripheral veins, and in higher doses periheral arteries, reduces preload and after load, and thereby lowers myocardial oxygen condumption
• Inhibition of platlet aggregation

Question 9

Why does admision of oral nitrates need to be administered at a high dose ?

Answer 9

First pass metabolism occurs in the liver which reduced the bioavailability of the nitrate

Question 10

Why are short acting nitrates administered and what are there used?

Answer 10

Provide relief of an acute anginal attack

Used before physical activities to prevent anginal attacks

Question 11

What are the benifits of sublingual tablets?

Answer 11

Absorption of drug through the oral mucous and direct access to the systemic circulation avoiding GIT

Fast action

Question 12

What are long-acting nitrates used for ?

Answer 12

prophylaxis: to reduce the number of attacks that occur by using the medicine regularly in a long term basis

Question 13

What are the disadvantages of long-acting nitrates and how can this be reduced

Answer 13

Nitrate toletrance- impares responsiveness

Have a break period (remove the patch for some time)

Question 14

What is cross-tolerance in terms of nitrates

Answer 14

Stops other vasodilaters from working