Adult: 15-100 mg in 500 mL of NaCl 0.9% or dextrose 5% inj given via infusion; adjust the rate of infusion according to response. In case of grave emergencies: Initially, 0.5-5 mg via direct inj, followed by infusion of 15-100 mg in 500 mL of NaCl 0.9% or dextrose 5% inj.
Reconstitution
IV infusion: Dilute 15-100 mg with 500 mL of NaCl 0.9% or dextrose 5% inj. Recommendations may vary among countries and individual products (refer to specific product guidelines).
Special Precautions
Patient with hypertension, diabetes mellitus, heart or thyroid disease, cirrhosis. Avoid extravasation. Avoid concomitant use with cyclopropane or halothane anaesthesia unless clinically needed. May provoke relapse in patients with history of malaria. May cause prolonged elevation of blood pressure even after discontinuation (cumulative effect). Elderly. Pregnancy and lactation.
Adverse Reactions
Significant: Cardiac arrhythmias or arrest and pulmonary oedema (rapidly induced hypertensive episodes). Cardiac disorders: Palpitations, bradycardia, sinus or ventricular tachycardia. Gastrointestinal disorders: Nausea. Infections and infestations: Rarely, abscess formation. Musculoskeletal and connective tissue disorders: Rarely, soft tissue necrosis. Nervous system disorders: Headache. Skin and subcutaneous tissue disorders: Rarely, sloughing. Vascular disorders: Hypertension, peripheral ischaemia.
Symptoms: Severe hypertension, headache, constricting chest sensation, diaphoresis, nausea, vomiting, euphoria, pulmonary oedema, convulsion, tachycardia, bradycardia, sinus arrhythmia, atrial or ventricular arrhythmia, MI, and cardiac arrest. Management: Local ice packs may delay absorption if administered via IM or SC inj. Discontinue IV infusion immediately but reinstate if hypotension occurs. If necessary, α-adrenergic blockers may be useful for reducing hypertension and may be beneficial on cardiac arrhythmia. Parenteral diazepam may be used for convulsions.
Drug Interactions
Increased action with MAOIs and TCAs. Decreased pressor effect with α-adrenergic blockers. Concomitant use with digitalis may cause ectopic arrhythmia.
Action
Description: Mechanism of Action: Metaraminol is a sympathomimetic amine. It directly and indirectly acts on α- and β-adrenergic receptors causing peripheral vasoconstriction, increased systolic and diastolic blood pressure, and elevated force of myocardial contractions. The α-adrenergic activity of metaraminol is predominant than the β-adrenergic activity. Onset: 1-2 minutes. Duration: Approx 20-60 minutes.
C01CA09 - metaraminol ; Belongs to the class of adrenergic and dopaminergic cardiac stimulants excluding glycosides. Used in the treatment of hypotension.
References
Anon. Metaraminol. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 26/06/2023.Buckingham R (ed). Metaraminol Tartrate. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 26/06/2023.Joint Formulary Committee. Metaraminol. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 26/06/2023.Max Health Ltd. Metaraminol 0.5 mg/mL Solution for Injection data sheet 01 October 2021. Medsafe. http://www.medsafe.govt.nz. Accessed 26/06/2023.Metaraminol 0.5 mg/mL Solution for Injection (Wockhardt UK Ltd). MHRA. https://products.mhra.gov.uk. Accessed 26/06/2023.Metaraminol 10 mg/mL Solution for Injection or Infusion (Wockhardt UK Ltd). MHRA. https://products.mhra.gov.uk. Accessed 04/10/2023.