ADMINISTRATION ROUTES:
IV, Sublingual, Transdermal
ALTERNATIVE NAMES:
GTN, Nitronal, Lycinate, Glytrin, Nitrolingual, Minitran, Nitroderm
ICU INDICATIONS:
- Afterload reduction by peripheral vasodilation
- Treatment of hypertension
- Treatment of angina
PRESENTATION AND ADMINISTRATION:
IV:
Nitronal 50 mL contains 50 mg of GTN in 50 mL of 5% dextrose
Use undiluted
GTN is readily absorbed into many plastics. Original Perfusor PE tubing causes minimal absorption and is preferred. If other plastics are used, GTN may be absorbed by the tubing, particularly when running at low rates. When the appropriate infusion sets are used, the calculated dose will be delivered to the patient because the loss of nitroglycerin due to absorption in standard PVC tubing will be kept to a minimum. Doses commonly used in published studies used general-use PVC infusion sets and recommended doses based on this experience are too high if the low-absorbing infusion sets are used.
Compatible with the following IV fluids:
5% dextrose, Normal saline, Glucose and sodium chloride
Do not mix with other medications
Store at room temperature and protect from light
Transdermal:
Apply once daily to chest or upper arm for 12-18 hours (brand dependent) followed by a 6-12 hour nitrate-free period (usually overnight)
Minitran 5 mg/24 hours and 10 mg/24 hours
Nitroderm TTS 5 mg/24 hours (25 mg) and 10 mg/24 hours (50 mg)
Sublingual tablets:
Lycinate 600 mcg tablets
Sublingual spray:
Glytrin spray 400 mcg/dose
Nitrolingual pump spray 400 mcg/dose
DOSAGE:
IV infusion:
Begin infusion at 5 mL/hr and titrate to effect
Infusion dose range is 0 - 12 mL/h (equivalent to 0 - 200 mcg/min)
Transdermal:
Begin with 5 mg/24 hours patch; maximum two 10 mg/24 hours patches
Sublingual tablets:
1 tablet under the tongue every 3-5 mins as required
DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:
Dose as in normal renal function
DOSAGE IN PAEDIATRICS:
IV infusion:
For children < 30 kg
3 mg/kg in 50 mL 5% dextrose at 0.5 - 5 mL/hr (0.5 - 5 mcg/kg/min)
For children ≥ 30kg
3 mg/kg in 100 mL 5% dextrose at 1 - 10 mL/hr (0.5 - 5 mcg/kg/min)
CLINICAL PHARMACOLOGY:
The principal pharmacologic action of nitroglycerin is relaxation of vascular smooth muscle, producing a vasodilator effect on both peripheral arteries and veins with more prominent effects on the latter. Dilation of the postcapillary vessels, including large veins, promotes peripheral pooling of blood and decreases venous return to the heart, thereby reducing left ventricular end-diastolic pressure (preload). Arteriolar relaxation reduces systemic vascular resistance and arterial pressure (afterload).
CONTRAINDICATIONS:
- Known hypersensitivity to glyceryl trinitrate
WARNINGS:
Occasionally, high dose GTN may worsen oxygenation due to increased shunting
PRECAUTIONS:
General:
GTN may lead to severe hypotension in patients with haemodynamically significant aortic stenosis
Laboratory Tests:
No tests in addition to routine ICU tests are required
Drug/Laboratory Test Interactions:
None of note
IMPORTANT DRUG INTERACTIONS IN ICU:
Amplification of the vasodilatory effects of nitroglycerin by sildenafil can result in severe hypotension. Additive effects may be observed when GTN is combined with other antihypertensives
ADVERSE REACTIONS:
Body as a Whole:
Allergic reactions
Cardiovascular System:
Tachycardia, hypotension, syncope, rebound hypertension, palpitations
Gastrointestinal System:
Nausea, vomiting, abdominal pain
Central Nervous System:
Headache
Haematological System:
Methaemoglobinaemia