Nitrate / Vasodilator Sublingual
Glyceryl Trinitrate (GTN)
Nitroglycerin
CPG Reference
Chest Pain / Acute Coronary Syndrome
Indications
- ✓ Chest pain/discomfort of presumed cardiac origin not relieved by rest and reassurance with: Systolic BP > 90 mmHg AND Heart rate is between 50-150 beats per minute
Contraindications
- ✕ Hypersensitivity
- ✕ Hypotension < 90 mmHg
- ✕ Ventricular Tachycardia (VT)
- ✕ Sildenafil (Viagra® / Revatio®), Vardenafil (Levitra®) or Avanafil (Spedra®) use in the previous 24 hours
- ✕ Tadalafil (Cialis®) use in the previous 3 days
- ✕ Riociguat (Adempas®) use in the previous 24 hours
Precautions
- ⚠ Nitrates are an early intervention and should not be delayed until on the stretcher or inside the ambulance
- ⚠ Administer to the patient in a seated or semi-recumbent position
- ⚠ Prime the bottle before using it for the first time by pressing the nozzle 5 times, spraying it into the air
- ⚠ Do not shake GTN bottle prior to administration
- ⚠ Assess BP before every dose
- ⚠ Severe hypotension is an uncommon side effect
- ⚠ Intoxication (effects are enhanced)
- ⚠ Phosphodiesterase 5 inhibitor medication administration in previous 4 days
- ⚠ When using SJWA supplied GTN spray bottle, assess whether it can be reused and wipe with approved detergent disinfectant wipe after use
- ⚠ Crews are not to leave the remaining SJWA supplied medication with the patient — against the SJWA poisons licence and the Medicines and Poisons Act 2014
Dosing
Adult
Amount 400 microg (1 spray)
Route Sublingual
Repeat If pain persists after 5 minutes and BP maintained, consider further sprays at 5-minute intervals. Should the first 3 doses provide some relief but symptoms persist, continue with further doses at 5-minute intervals if no contraindications.
EHS scope: sublingual spray only. GTN infusion is outside EHS scope.
Onset: Refer to current CPG
Side Effects & Notes
Side Effects
- • Hypotension (rare)
- • Tachycardia
- • Flushing
- • Headache
- • Dizziness
Drug Interactions
- ⚠ Sildenafil, Vardenafil, Avanafil — contraindicated within 24 hours
- ⚠ Tadalafil — contraindicated within 3 days
- ⚠ Riociguat — contraindicated within 24 hours
- ⚠ Phosphodiesterase 5 inhibitors generally — use with caution within 4 days
- ⚠ Intoxication enhances GTN effects
Clinical Notes
- → Aspirin should be administered in conjunction with GTN for ACS as per CPG
- → Assess BP before every dose — do not administer if systolic BP < 90 mmHg
- → Heart rate must be between 50-150 bpm before administration
- → If pain > 3/10 after 1 spray of GTN, consider Methoxyflurane for additional analgesia
- → Do not use GTN in Congestive Cardiac Failure (CCF) — may over-stimulate a failing heart and exacerbate symptoms
- → GTN infusion for ACS/ACPO is outside EHS scope (Critical & Extended Care only)