Midazolam Flashcards
Midazolam
2 preparations
- Dilution – 5mg (1mL) midazolam diluted with 4mL sodium chloride 0.9% to 5mL total volume. (1mg:1mL)
- Morphine/Midazolam Mix - 10mg (2mL) midazolam mixed with 10mg (1mL) morphine and diluted with 7mL sodium
chloride 0.9% to 10mL total volume. Morphine/Midazolam solution - 1mL = 1mg midazolam + 1mg morphine.
Midazolam
Pharmacology 2
- Midazolam is a short acting benzodiazepine which potentiates the inhibitory effects of GABA throughout the CNS,
resulting in anxiolytic, sedative, hypnotic, anterograde amnesic, muscle relaxant and anti-epileptic effects. - The effects of midazolam on the CNS are dependent on the dose administered, the route of ad-ministration and the
presence or absence of other premedications.
Midazolam
Metabolism 3
- Midazolam is metabolised by the liver and kidneys with 60-80% of metabolites excreted in urine.
- In adults over 60 years of age, the elimination half-life of midazolam may be prolonged up to four times.
- In patients with hepatic impairment, critical illness, cardiac insufficiency and obesity the elimination half-life is prolonged.
Midazolam
Route Onset Duration Half-life
IM/Subcut
IV/IO
Intranasal
Midazolam
Route Onset Duration Half-life
IM/Subcut 5-10min 30min 1.5-2hrs
IV/IO 1-3min 20min 20min
Intranasal 1-3min 20min 1.5-2hrs
Midazolam
Indications
2 CPG
8 Protocol Specific
CPG Indication/s
* Agitation in the trauma and critically ill patient.
* Behavioural disturbance.
Protocol Specific Indication/s
* Cardiac Arrest (C3).
* Distressing psychological reactions post ketamine administration.
* Dysrhythmias - Bradycardia (C7).
* Hypertensive disorders of pregnancy (OA4).
* Limb realignment and/or difficult extrication (T16).
* Palliative care (S9).
* Return of spontaneous circulation (ROSC) (C16).
* Seizures (M9).
Midazolam
Contraindications 1
⛔ Allergy or known hypersensitivity to benzodiazepines.
Midazolam
Adverse / Side Effects
Common
Infrequent
Rare
- Common (>1%) – hypotension, hiccup, cough.
- Infrequent (0.1 – <1%) – pain on injection, erythema at injection site, rash, laryngospasm, bronchospasm, nausea,
vomiting, headache, confusion, restlessness. - Rare (<0.1%) – arrhythmias, cardiorespiratory arrest, anaphylactic/anaphylactoid reactions.
Midazolam
Precautions / Warnings
Non AI
- Consider reduced doses in patients who have low body weight, respiratory disease, sleep apnoea, acute alcohol
intoxication, shock and coma, myasthenia gravis, muscular dystrophies and myotonias as respiratory depression may be
prolonged or increased. - Use in the elderly – There have been reports of falls and fractures in benzodiazepine users. The risk is increased in those
taking concomitant sedatives (including alcoholic beverages). Elderly patients are at an increased risk of oversedation,
ataxia, confusion, falls, respiratory depression, and short-term memory impairment; reduce dose and monitor closely. - Use in renal impairment – There is a greater likelihood of adverse drug reactions in patients with severe renal
impairment. - Use in hepatic impairment – Hepatic impairment reduces the clearance of i.v. midazolam with a subsequent increase in
terminal half-life. Therefore, the clinical effects may be stronger and prolonged. The required dose of midazolam may have
to be reduced and proper monitoring of vital signs should be established. - Use in pregnancy (Category C) – Benzodiazepines should be avoided during pregnancy unless there is no safer
alternative. Midazolam crosses the placenta and the administration of midazolam in the last weeks of pregnancy or at high
doses during labour have resulted in neonatal CNS depression and can be expected to cause irregularities in the foetal
heart rate, hypothermia, hypotonia, poor sucking and moderate respiratory depression due to the pharmacological action
of the product. - Use in lactation - There is evidence that midazolam is excreted in breast milk and its effects on the newborn are not
known. Therefore midazolam is not recommended for use in nursing mothers. - Effects on Ability to Drive and Use Machines - Patients should be warned to take extra care as a pedestrian and
not to drive a vehicle or operate a machine until the patient has completely recovered from the effects of the drug, such
as drowsiness. The physician should decide when activities such as driving a vehicle or operating a machine may be
resumed. The patients’ attendants should be made aware that the patients’ anterograde amnesia may persist longer than
the sedation and therefore, patients may not carry out instructions even though they appear to acknowledge them. If sleep
duration is insufficient or alcohol is consumed, the likelihood of impaired alertness may be increased.
Midazolam
Precautions / Warnings
Abbreviated
6
The selected text outlines precautions and warnings for the use of midazolam:
Reduced doses: Necessary for patients with low body weight, respiratory disease, sleep apnoea, acute alcohol intoxication, shock, coma, myasthenia gravis, muscular dystrophies, and myotonias due to prolonged or increased respiratory depression.
Elderly patients
Renal impairment
Hepatic impairment
Pregnancy
Lactation
Driving and operating machines
Midazolam
Interactions
- Concomitant use of barbiturates, alcohol or other central nervous system depressants increases the risk of underventilation
or apnoea and/or cardio-ventricular depression and may contribute to a profound and/or prolonged drug effect,
that could result in coma or death.
Midazolam
Notes
- Patients administered midazolam should be warned:
- They may not be able to remember events that occur while this medication is having an effect and this loss of memory
may last longer than the period of sedation. - I f not transported, a responsible person must be available to look after them and they should not drink alcohol during
this period (for up to 12 hours).
Midazolam
CIPRIC
ADULT ONLY DOSE
IV - Diluted
Initial Dose: 2.5mg diluted bolus
Repeat: 5 minutes
Maximum Total Dose: 7.5mg
IM
Initial Dose: 5mg bolus
Repeat: 5 minutes
Maximum Total Dose: 10mg
Midazolam
Distressing psychological reactions post Ketamine
Dose >=14yo
IV - Diluted
Initial Dose: 0.5 – 1mg diluted bolus
Repeat: May be repeated once (0.5mg) if the initial dose was 0.5mg
Maximum Total Dose: 1mg
Midazolam
Distressing psychological reactions post Ketamine
Dose 6-14years
IV - Diluted
Initial Dose: 0.5mg diluted bolus
Repeat: Nil
Maximum Total Dose: 0.5mg
Midazolam
Bradycardia
Distress / Pain post initiation of transcutaneous pacing
ADULT ONLY
IV - Diluted
Initial Dose: 1mg diluted bolus
Repeat: 3 minutes
Maximum Total Dose: 5mg
Note – The IV regimen may be repeated 20 minutes post last administration.
Midazolam
To facilitate limb realignment and/or difficult extrication post analgesia administration.
Ages 10-64
IV - Diluted
Initial Dose: 1mg diluted bolus
Repeat: 3 minutes
Maximum Total Dose: 5mg
Midazolam
To facilitate limb realignment and/or difficult extrication post analgesia administration.
Ages >=65
IV - Diluted
Initial Dose: 0.5mg diluted bolus
Repeat: 3 minutes
Maximum Total Dose: 2.5mg
Midazolam
Palliative Care
* Pain / breathlessness in the last days of life where anxiety is present.
* Restlessness and/or agitation in the last days of life as a second line medication where droperidol is ineffective or
contraindicated.
Note – The regimens for all indications may be repeated 2 hours post last administration.
ADULT ONLY
Subcut
Initial Dose: 2.5mg bolus
Repeat: 15 minutes
Maximum Total Dose: 5mg (episode), 15mg (24hours)
Midazolam
Hypertensive disorders of pregnancy (OA4)
Seizures (Protocol M9)
Indication - Seizures.
Dose Adult
IM
Initial Dose: 5mg bolus
Repeat: 5 minutes
Maximum Total Dose: 15mg
IV/IO - Diluted
Initial Dose: 2.5mg diluted slow bolus
Repeat: 5 minutes
Maximum Total Dose: 15mg
Midazolam
Hypertensive disorders of pregnancy (OA4)
Seizures (Protocol M9)
Indication - Seizures.
Dose Paed
Intranasal Initial
Dose: 0.3mg/kg (max bolus 5mg)
Repeat: Nil
Maximum Total Dose: 0.3mg/kg
IM
Initial Dose: 0.15mg/kg (max bolus 5mg)
Repeat: 5 minutes
Maximum Total Dose: 0.45mg/kg
IV/IO - Diluted
Initial Dose: 0.15mg/kg (max bolus 2.5mg)
Repeat: 5 minutes
Maximum Total Dose: 0.45mg/kg
Midazolam
ROSC
Post ROSC Sedation
Preparation
Dilution – 10mg (2mL) midazolam mixed with 10mg (1mL) morphine and diluted with 7mL sodium chloride 0.9% to 10mL total volume.
Morphine/Midazolam solution - 1mL = 1mg midazolam + 1mg morphine.
Midazolam
ROSC
Post ROSC Sedation
NOTE
Notes – IV Regimen for Post Intubation/SGA Sedation may be repeated 20 minutes after the last administration.
Midazolam
ROSC
Post ROSC Sedation
Dose Adult
IV/IO
Initial Dose: 2.5mL morphine/midazolam mix bolus
Repeat: 3 minutes
Maximum Total Dose: 15mL
IM
Initial Dose: 5mL morphine/midazolam mix bolus
Repeat: 15 minutes
Maximum Total Dose: 15mL
Midazolam
ROSC
Post ROSC Sedation
Dose Paed (≥ 6 months of age)
IV/IO
Initial Dose: 0.1mL/kg morphine/midazolam mix bolus (max bolus 2.5mL)
Repeat: 3 minutes
Maximum Total Dose: 0.3mL/kg
IM
Initial Dose: 0.1mL/kg morphine/midazolam mix bolus (max bolus 2.5mL)
Repeat: 15 minutes
Maximum Total Dose: 0.3mL/kg
