NITRATES

Question 1

Nitrates - examples

Answer 1

Isosorbide mononitrate
(long-acting)

Glyceryl trinitrate 
(short-acting)

Question 2

Nitrates - example of short-acting and when it is given

Answer 2

Glyceryl trinitrate 
(short-acting)

Short acting GTN used for symptomatic relief in angina

AND

Used in initial therapy for acute coronary syndrome (ACS) - remember MONA for ACS initial treatment (morphine, oxygen, nitrates, aspirin)

Question 3

Nitrates - example and indication of long-acting

Answer 3

Isosorbide mononitrate
(long-acting)

Long acting ISMN used for prophylaxis of angina where Beta blocker and/or Calcium channel blockers are insufficient/not tolerated

Question 4

Nitrates - when are IV nitrates indicated

Answer 4

Pulmonary Oedema

ACS (can also be given sublingually)

Question 5

Nitrates - administration

Answer 5

Stable angina patients GTN given as:
Sublingual tablet
Sublingual spray

Patients with ACS or HF:
GTN given as continuous IV infusion

Isosorbide mononitrate for Angina prophylaxis:
Tablet

Question 6

Nitrates - MOA

Answer 6

Nitrates are converted to NO

NO causes REDUCED Ca2+ uptake by vascular smooth muscle cells = venous vasodilation

=
→ relaxation of venous vessels = ↓cardiac preload and and subsequent workload of heart

→ reduces cardiac work and myocardial oxygen demand

These relieve angina and cardiac failure

Question 7

Nitrates - adverse effects

Answer 7

→ Flushing

→ Headaches

→ Light headedness

→ Hypotension

→ Sustained use can lead to tolerance (e.g isosorbide mononitrate)

Question 8

Nitrates - interactions

Answer 8

Do NOT use with phosphodiesterase inhibitors (PDEi) such as sildenafil / theophylline

Why? Enhance and prolong hypotensive effects of nitrates

Used in caution with patients on antihypertensive medication
Why? May precipitate hypotension

Question 9

Nitrates - contraindicated (avoid)

Answer 9

→ severe aortic stenosis
→ haemodynamic instability
→ hypotension

Question 10

Nitrates - monitoring when giving IV nitrates

Answer 10

monitor BP frequently and adjust infusion rate to ensure systolic >90

Question 11

Nitrates - patient communicaton when using GTN spray

Answer 11

Advise use of sublingual GTN prior to tasks that usually trigger their angina

Sit and rest 5 mins before and after taking GTN

Question 12

Nitrate - how to explain to a patient what GTN spray does for their angina

Answer 12

• Works by opening up the blood vessels that supply your heart so that your heart is supplied with enough oxygen – this should then improve your symptoms you usually experience
• Use BEFORE known triggers and/or DURING attacks
• Can be given as a spray or a tablet that you use under your tongue - One tablet OR one spray under the tongue

Question 13

Nitrate - explain to a patient how to use GTN spray or angina attacks

Answer 13

Spray - take a deep breath, open mouth and lift tongue, one spray under tongue, close mouth, breathe through nose and rest and wait for 5 mins

Patient instructions for taking sublingual GTN spray:
Upon chest pain and/or before activities that trigger pain take spray whilst seated and wait 5 mins
If there is still pain 5 mins after then repeat dose and wait another 5 mins
if pain worsens or remains (after 2 doses) then call 999 (could be MI)