metaraminol (Aramine)

see also:

• inotropes
• sympathomimetics

• a vasopressor which can be used as iv bolus peripherally for short term Mx of hypotension
• it is particularly useful at induction of anaesthesia to counteract the hypotensive effects of most induction agents in at risk patients where iv fluid bolus is not sufficient.
• mechanism of action:
  • indirect action via stimulating release of noradrenaline / norepinephrine
  • direct actions as alpha agonist and to a lesser extent, beta agonist
• duration of action ~20 min following iv bolus
• avoid in cardiogenic shock or decompensated mitral regurgitation where increased LV afterload may be harmful.
• marketed as Aramine

• allergy and hypersensitivity reactions in patients sensitive to sulphites - thus care in patients with asthma
• ventricular arrhythmias including ventricular tachycardia (VT), especially in patients with acute myocardial infarction (AMI/STEMI/NSTEMI)
• severe hypertension if excessive dosing which may cause acute pulmonary oedema (APO), ventricular tachycardia (VT) and choking / respiratory arrest / cardiac arrest / BLS / ALS / CPR
• cumulative effect is possible which may cause prolonged hypertension
• vasoconstriction
  • use with care in those with heart disease, thyroid disease, hypertension, or diabetes
  • may cause local ischaemia and abscesses if used im
  • prolonged vasoconstriction may prevent adequate volume expansion of circulation and lead to persistent shock
  • may cause fetal hypoxia in pregnant patients

• usual bolus dose 0.5-1mg repeated as necessary with care
• DO NOT give 1 ampoule as bolus - 1 ampoule contains 10mg!!
• dilute 1 ampoule to 10ml to allow more precise titrated doses.