Norepinephrine Injectable: Shock Dosing and Precautions

Therapeutic action

Sympathomimetic.

Indications

Acute hypotension despite fluid therapy in shock. In children, epinephrine is preferred for this indication.

Forms and strengths, route of administration

This drug should only be used by well trained personnel in well-equipped hospitals.

• 8 mg of norepinephrine tartrate in 4 ml ampoule (2 mg/ml), equivalent to 4 mg of norepinephrine base in 4 ml (1 mg/ml), for IV infusion.

Dose

The doses are expressed as norepinephrine tartrate and are intended for peripheral IV administration only.

• Use diluted solution in 0.9% sodium chloride, 5% glucose, or Ringer lactate.
• Child under 40 kg: add 1 ml (2 mg of NEP tartrate) to 39 ml diluent to obtain a 0.05 mg/ml solution (50 micrograms/ml).
• Child 40 kg and over and adult: add 2 ml (4 mg of NEP tartrate) to 38 ml diluent to obtain a 0.1 mg/ml solution (100 micrograms/ml).
• Administer by continuous IV infusion using an infusion or syringe pump.
• Child and adult: 0.1 microgram/kg/minute, increasing if necessary by 0.05 microgram/kg/minute every 10 minutes for the first hour, then every hour, maximum 1 microgram/kg/minute.
• Once desired response is achieved, discontinue gradually in decrements of 0.05 microgram/kg/minute every hour. Do not discontinue abruptly.
• Infusion rate formula: [desired dose (microgram/kg/minute) x weight (kg) x 60 minutes] divided by concentration (microgram/ml).

Contra-indications, adverse effects, precautions

• Administer with caution to patients with hypertension, hypotension due to volume depletion except as an emergency measure, thrombosis, hyperthyroidism, and to older patients.
• May cause arrhythmia, hypertension, agitation, headache, and tissue necrosis following extravasation. Use a large vein for IV administration.
• Pregnancy and breast-feeding: no contra-indication.
• Norepinephrine is colourless: discard any ampoules with a pink or brownish colour.