Midazolam

Question 1

Midazolam - Drug class

Answer 1

Benzodiazepine (short acting)

Question 2

Midazolam - Pharmacology

Answer 2

Midazolam hydrochloride is a short acting CNS depressant that induces amnesia, anaesthesia, hypnosis and sedation. It achieves this by enhancing the action of the inhibitory neurotransmitter gamma-amino butyric acid (GABA). Depressant effects occur at all levels of the CNS.

Question 3

Midazolam - Metabolism

Answer 3

By the liver and excreted by the kidneys

Question 4

Midazolam - Indications

Answer 4

• Generalised seizures / focal seizures (GCS < or equal to 12)
• Sedation for maintenance of an established LMA/ETT
• Sedation for procedures (e.g. TCP or cardio version)
• Sedation to facilitate safe assessment & treatment of agitated head injured patients
• Sedation as an adjunct to opiate analgesia (fracture splinting / extrication / burns)
• Sedation for ketamine emergence

Question 5

Midazolam - Contraindications

Answer 5

KSAR or hypersensitivity to midazolam

Question 6

Midazolam - Precautions

Answer 6

• Reduced dosages should be used in elderly patients, patients with chronic renal failure, congestive cardiac failure, or shock
• Can cause severe respiratory depression in patients with COPD
• Myasthenia graves
• Multiple sclerosis

Question 7

Midazolam - Side Effects

Answer 7

• Hypotension

- Respiratory depression particularly when associated with other CNS depressants including alcohol and narcotics.

Question 8

Midazolam - Presentation

Answer 8

ampoule 5mg/1mL

Question 9

Midazolam - Onset, duration, half-life

Answer 9

Onset - IM 5-15 mins, IV 1-3 mins
Duration - variable
Half-life - 2.5 hours

Question 10

Midazolam - Schedule

Answer 10

S4 Restricted drugs

Question 11

Midazolam - Routes of Administration

Answer 11

NAS, IM

Question 12

Midazolam - Adult dosages - Generalised or focal seizures (GCS < or equal to 12)

Answer 12

NAS - > (or equal to) 70 yrs - 2.5mg
repeated every 10 mins
total max dose 10mg
NAS - < 70 yrs - 5mg
repeated every 10 mins
total max dose 20mg

IM - > (or equal to) 70 yrs - 2.5mg
repeated every 10 mins
total max dose 10mg
IM - < 70 yrs - 5mg
repeated every 10 mins
total max dose 20mg

Question 13

Midazolam - Paediatric dosages - Generalised or focal seizures (GCS < or equal to 12)

Answer 13

NAS - 200 microg/kg
single dose not to exceed 5mg
repeated at half the initial dose (max 2.5mg) every 10 mins
total max dose 10mg

IM - 200 microg/kg
single dose not to exceed 5mg
repeated at half the initial dose (max 2.5mg) every 10 mins
total max dose 10mg

Question 14

Midazolam - Special notes

Answer 14

• Focal seizure activity in a patient who is unconscious or has ALOC (GCS < or equal to 12) should be treated as a generalised seizure. For patients with a GCS > 12, officers should discuss treatment options with the QAS on-call medical officer
• If a patient has received midazolam or diazepam prior to arrival of paramedics, the amount administered is to be taken into account in the total dose administered
• The QAS clinical consultation and advice line should be contacted for all seizures failing to respond to QAS initiated treatment.