Midazolam Intravenous for Adults

Who can administer

Administration RESTRICTED - see Appendix 1

Important information

• Flumazenil injection must be available at all times when administering midazolam by the intravenous route
• Midazolam should only be administered by experienced physicians in a setting fully equipped for the monitoring and support of respiratory and cardiovascular function
• Not to be used for conscious sedation in patients with severe respiratory failure or acute respiratory depression
• Acute respiratory depression, respiratory arrest and cardiac arrest may occur especially when used for sedation in non-critical care settings
• The need for a continuous infusion should be reassessed daily to reduce the risk of accumulation and prolonged recovery (particularly in patients with renal and hepatic impairment)
• For Y-site compatibility see below

Available preparations

Hypnovel 10mg per 2mL ampoule

Hypnovel 10mg per 5mL ampoule

Reconstitution

Already in solution

Draw up using a 5 micron filter needle

Infusion fluids

Sodium chloride 0.9% or Glucose 5%

Methods of intravenous administration

Slow intravenous injection

• Consider using the 10mg per 5mL strength to allow for more accurate dose measurement and titration
• Administer required dose at a rate of 2mg per minute

Continuous intravenous infusion (critical care areas only). Administer using an electronically controlled infusion device

• Use 12ml of 10mg/2mL strength, and add 48ml infusion fluid to produce a 60mg in 60mL (1mg/1mL) infusion

Dose in adults

Conscious sedation for procedures

• Adults less than 60 years: Initial dose: 2 to 2.5mg, given five to ten minutes before the beginning of the procedure. Further doses of 1mg may be given, as necessary, to a total dose of 3.5 to 7.5mg
• Adults 60 years or more, debilitated or chronically ill: Initial dose: 0.5 to 1mg, given five to ten minutes before the beginning of the procedure. Further doses of 0.5 to 1mg may be given, as necessary to a total dose of 3.5mg
• Consider using the 10mg per 5mL strength to allow for easier dose measurement and titration

Anaesthesia

• Used as per theatre guidelines

Sedation in intensive care units

• In hypovolemic, vasoconstricted, or hypothermic patients, both the loading and maintenance doses should be reduced
• Escalate in increments of 1 to 2.5mg every two minutes
• Infusion maintenance doses vary but are in the range of 2.1 to 14mg/hr for a 70kg patient (30 to 200 microgram/kg/hour)
• Abrupt discontinuation after prolonged intravenous administration may lead to withdrawal symptoms
• Consider reducing slowly when stopping drug

Renal impairment

• In patients with renal impairment (CrCl < 30ml/min), midazolam may be accompanied by more pronounced and prolonged sedation, including clinically relevant respiratory and cardiovascular depression
• Such patients should be dosed carefully and dose titrated for the desired effect

Hepatic impairment

• In patients with hepatic impairment, the clinical effects of midazolam may be prolonged
• The required dose of midazolam may have to be reduced

Adults over 60 years of age:

• Use lower doses for all indications except ICU sedation

Monitoring

• Monitor respiratory and cardiovascular parameters
• Monitor blood pressure - hypotension is more common in patients also on opioids ^{(ref 1)}

Special caution should be excercised in the following patients

• Adults over 60 years of age
• Chronically ill or debilitated patients
• Chronic respiratory insufficiency - respiratory arrest is more common with high doses/rapid administration
• Chronic renal failure, impaired hepatic or cardiac function

Further information

• The elimination half life may be prolonged up to six times in critically ill patients

Storage

Store below 25⁰C

References

Hypnovel 10mg/2mL SPC October 2019

Hypnovel 10mg/5mL SPC October 2019

(1) Uptodate, accessed online 19/10/2021

Therapeutic classification

Benzodiazepine