Myocardial ischaemia (stable angina)

Question 1

Short-acting nitrates

Answer 1

Management of acute angina attacks
- Glyceryl trinitrate
- Isosorbide dinitrate (S/L)

Question 2

Long-acting nitrates

Answer 2

Long-term prophylaxis of angina
- MR isosorbide dinitrate
- Isosorbide mononitrate

• Beta blockers
• CCBs
• Ivabradine
• Ranolazine
• Nicorandil

Question 3

Glyceryl trinitrate

Answer 3

Converted into nitric oxide which is a short-acting vasodilator that improves blood supply.
Available as S/L tablets or spray
Lasts 20-30 minutes
Using more than twice a week = long-term prophylaxis required.

Question 4

Glyceryl trinitrate - S/L tablets

Answer 4

• Special container (foil-lined with no wadding)
• Expires 8 weeks after opening

Question 5

Angina prophylaxis

Answer 5

1st line:
B-Blocker or CCB (e.g. diltiazem/verapamil)

2nd line:
Switch to B-Blocker or CCB depending on what was initially tried

If both B-Blockers and CCBs are contraindicated or not tolerated consider monotherapy with a vasodilator:
- A long-acting nitrate e.g. isosorbide mononitrate (only in normal sinus rhythum)
- Nicorandil
- Ivabradine
- Ranolazine

Question 6

Nicorandil

Answer 6

K channel activator
Risk of ulcer complications: mouth, skin, eye, GI
Do not drive until it is established and performance is not impaired.

Question 7

Nitrates - MoA

Answer 7

Potent coronary vasodilators.
Reduce venous return and cardiac output.

Question 8

Short-acting nitrate

Answer 8

GTN

Question 9

Long-acting nitrate

Answer 9

Isosorbide mononitrate BD (MR = OD)
MR Isosorbide dinitrate BD (can also be taken S/L; alternative to GTN)

Question 10

Tolerance

Answer 10

Occurs with long-acting preparations or transdermal patches.
Reduced symptom relief despite continued use.
Minimised by timing doses to avoid significant nitrate exposure overnight (not needed at this time)

Question 11

Transdermal patches (GTN)

Answer 11

Leave patches off for 8-12 hours (overnight) in a day

Question 12

MR Isosorbide dinitrate and Isosorbide mononitrate

Answer 12

Both taken BD.
Second dose should be taken after 8 hours.

Question 13

MR Isosorbide mononitrate

Answer 13

Taken OD
Does not produce tolerance

Question 14

Nitrates - Side effects

Answer 14

Flushing
Headaches/light-headedness
Hypotension (postural)
Dizziness
Tachycardia
Dyspepsia
Heartburn

Question 15

Injection (GTN + IDN) - SE

Answer 15

Severe hypotension
Sweating
Apprehension
Restlessness
Muscle twitching
Retrosternal discomfort
Palpitation

Question 16

Nitrates - withdrawal

Answer 16

AVOID abrupt withdrawal of nitrates (and CCB) as it worsens angina.