|Reviewed by Dr Carl
Kuschel and Brenda Hughes
Description information changed to note 2 different strengths December 2004
- Slow IV push
50 to 150 micrograms/kg as a slow push over 5 minutes. Can be repeated Q2-4H
Give lower dose if opiates being administered simultaneously.
- Continuous intravenous infusion
10-60 micrograms/kg/hour. Dosage can be increased if necessary.
Midazolam (micrograms) in 50ml IV solution =
50 x weight (kg) x dose
- Anticonvulsant (3rd or 4th line).
Contraindications and Precautions
- Known hypersensitivity to midazolam.
- Caution in preterm infants, especially extreme immaturity.
- Caution in neonates with hepatic or renal impairment.
- Caution when concurrent use with opiates, particularly
- Caution when concurrent use with other anticonvulsants.
- Concurrent administration with erythromycin promotes accumulation.
- May alter the depth of and prolong the recovery from concurrent neuromuscular blockade.
- Xanthines may decrease the anaesthetic/sedative effect of benzodiazepines. Care needs to be taken with
adding or withdrawing caffeine or aminophylline.
imidazobenzodiazepine, has anxiolytic, sedative, muscle relaxant and
anticonvulsant actions. Facilitates the action in the brain of gamma
aminobutyric acid, a naturally occurring neurotransmitter. Absorption 30% with
oral and 50% with nasal administration. Rapid and extensive distribution. Highly
protein bound. Hepatic metabolism to active and inactive derivatives, impaired
by poor hepatic perfusion . Very slow elimination via the kidneys. Elimination
half-life variable (6-7 hours in infants close to term, longer in less mature
infants), with the major metabolite (1-hydroxymidazolam) having an even shorter
half-life. Rapid onset of action (<3 minutes) and peak sedative action <20
minutes after IV administration. Anticonvulsant action may be more rapid. The IV
preparation has a pH of 3.
Possible Adverse Effects
- Hypotension and reduced cardiac output, particularly when used in combination with fentanyl.
- Respiratory depression and apnoea.
- Seizures or seizure-like activity may be seen following rapid bolus administration and in patients with underlying
- Cerebral blood flow velocities are reported to decrease transiently in preterm infants receiving midazolam boluses,
possibly reflecting the reduction in blood pressure.
- Nasal administration in children and adults has been reported to produce a burning sensation.
- Lower doses of midazolam should be considered in neonates with reduced cardiac output.
- Development of tolerance and a requirement for higher doses may occur with prolonged use.
- Prolonged use may result in neonatal abstinence syndrome.
- Recent systematic review has suggested that routine use of midazolam for sedation in ventilated infants is associated with an increased
incidence of adverse neurological outcomes.
- Management of midazolam overdose and/or toxicity: stop midazolam, supportive therapy (ventilation, volume
expansion etc.), consider use of specific antagonist flumazenil (very limited experience in the neonate).