What concentration of ketamine (intravenous anesthetic) is typically contained in a vial or ampule?

Ketamine Vial/Ampule Concentrations

Standard ketamine vials/ampules are available in three concentrations: 10 mg/mL (200 mg/20 mL), 50 mg/mL (500 mg/10 mL), and 100 mg/mL (1,000 mg/10 mL). 1

Available Formulations

• Ketamine hydrochloride injection is supplied as a clear, colorless to slightly yellow solution in the following concentrations 1:

  • 10 mg/mL: 200 mg/20 mL multiple-dose vials (NDC 55150-438-10)
  • 50 mg/mL: 500 mg/10 mL multiple-dose vials (NDC 55150-439-10)
  • 100 mg/mL: 1,000 mg/10 mL multiple-dose vials (NDC 55150-440-10)

• The 100 mg/mL concentration must be diluted before intravenous use 1

Clinical Applications and Dosing

• For intraoperative use in children, ketamine is typically dosed at 0.5 mg/kg as an adjunct to intraoperative opioids 2
• For S-ketamine (the S-enantiomer), the dose should be reduced to 0.25-0.5 mg/kg due to its higher potency 2, 3
• For breakthrough pain management in the PACU, ketamine can be administered at 0.5 mg/kg, titrated to effect 2
• For maintenance of anesthesia in children, a continuous infusion of 0.1-0.2 mg/kg/h (maximum 0.4 mg/kg/h) may be used 3

Pharmacokinetics

• Ketamine is extensively metabolized in the liver to its major active metabolite, norketamine, primarily by CYP2B6, CYP3A4, and CYP2C9 isoforms 4
• The elimination half-life of ketamine in humans ranges between 1.5 and 5 hours 4
• The bioavailability varies by route of administration:
  • Intramuscular: approximately 41% in children 5
  • Oral tablets: approximately 20% 6
  • Sublingual tablets: approximately 30% 6
  • Rectal suppository: approximately 30% 6
  • Nasal spray: approximately 45% 6

Storage and Handling

• Ketamine hydrochloride injection should be stored at 20°C to 25°C (68°F to 77°F) 1
• Vials should be protected from light 1
• The vial stopper does not contain natural rubber latex 1

Important Considerations

• When using ketamine for anesthesia or analgesia, continuous monitoring of vital parameters including ECG, pulse oximetry, and regular non-invasive blood pressure measurement is required 3
• For pediatric patients, weight-based dosing is essential, with careful consideration of the appropriate concentration for accurate dosing 2, 5
• The 100 mg/mL concentration requires dilution before intravenous administration to avoid adverse effects 1

Remember that ketamine is a controlled substance (Schedule III) and appropriate precautions should be taken for storage, handling, and documentation 1.