- Hypotension (particularly during induction of anaesthesia)
PRESENTATION AND ADMINISTRATION:
10 mg in 1 mL vial
Can be prepared in either 20 mL or 100 mL solutions of compatible fluid, both giving a concentration of 0.5 mg/mL
In 20 mL (for bolus or infusion): Dilute 10 mg (1 vial) in 20 mL of compatible IV fluid
In 100 mL (for infusion): Dilute 50 mg (5 vials) in 100 mL of compatible IV fluid
Compatible with the following IV fluids: Sodium Chloride, 5% dextrose, Hartmanns
Store at room temperature
Note: Section 29 drug (requires specific notification to Director-General of Health)
0.5-1 mg PRN
0.5 mg/mL solution given at 1-30 mL/hr
Titrate to required blood pressure. Can be given through a peripheral cannula. If doses escalating rapidly or maximal rate reached, change to noradrenaline administerd through central venous cannula
DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:
Dose as in normal renal function
DOSAGE IN PAEDIATRICS:
0.01 mg/kg PRN
Metaraminol is a potent sympathomimetic amine that increases both systolic and diastolic blood pressure.
- Hypersensitivity to metaraminol
Metaraminol contains sodium bisulfite, a sulfite that may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. The overall prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in non-asthmatic people.
Caution should be used to avoid excessive blood pressure response. Rapidly induced hypertensive responses have been reported to cause acute pulmonary oedema, arrhythmias, cerebral haemorrhage, or cardiac arrest.
Because of its vasoconstrictor effect metaraminol should be given with caution in heart or thyroid disease, hypertension, or diabetes.
No tests in addition to routine ICU tests are required
Drug/Laboratory Test Interactions:
IMPORTANT DRUG INTERACTIONS IN ICU:
Metaraminol should be used with caution in digitalised patients, since the combination of digitalis and sympathomimetic amines may cause ectopic arrhythmias.
Monoamine oxidase inhibitors or tricyclic antidepressants may potentiate the action of sympathomimetic amines. Therefore, when initiating pressor therapy in patients receiving these drugs, the initial dose should be small and given with caution.
Most adverse effects seen arise due to inadvertent excess dosing.
Hypertension, tachycardia, bradycardia, pulmonary oedema, atrial or ventricular arrhythmia
Central nervous system:
Cerebral haemorrhage, convulsions