Amber - For medicines normally initiated by a specialist but may be used by generalists

Introduction

Description: Short acting benzodiazepine.

Preparations

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Preparation

Dose

Format

Buccolam®

Licensed formulation in paediatrics

Midazolam Hydrochloride

5mg in 1ml

Pre-filled oral syringes of 2.5mg. 5mg, 7.5mg and 10mg  

 

Epistatus® 

Licensed formulation in paediatrics

Unlicensed formulation

Midazolam Maleate

10mg in 1ml

10mg/ml prefilled syringe (licensed formulation for 18 years or under)

Unlicensed formulations:

5ml bottle (4 x 1ml doses with 1ml overage) + 4 x 1ml oral syringes.


Also available as pre-filled oral syringes of 2.5mg, 5mg, 7.5mg

Note: Buccolam® and Epistatus® are not licensed for use in adults. Please check your local formulary for preferred product.

Buccolam® is half the strength of Epistatus® – be aware of difference in strength when prescribing.

 

Indications

  • Status epilepticus, as an alternative to subcutaneous midazolam or rectal diazepam.
  • Prolonged (longer than 5 or 10 minutes) convulsive epileptic seizures.
  • Sedative/anxiolytic in terminal haemorrhage.

 

Cautions

Use with caution in:

  • elderly patients
  • chronic renal failure
  • impaired hepatic function
  • impaired cardiac function.

 

Contra-indications:

  • Known hypersensitivity.
  • Marked neuromuscular respiratory weakness including unstable myasthenia gravis.
  • Severe respiratory depression.
  • Acute pulmonary insufficiency.

These are not absolute contra-indications if the patient is in the last days of life. Careful titration is however necessary.

 

Important drug interactions:

  • Midazolam is a major substrate of CYP3A4, interactions with CYP3A4 inhibitors such as clarithromycin.
  • Can cause central nervous system (CNS) depression if concurrent use with other CNS depressants such as opioids. Please refer to current edition of British National Formulary (BNF) for significant drug interactions.
  • Fatalities have occurred after concurrent administration with higher than approved doses of olanzapine.

 

Buccal midazolam pharmacokinetic data

Bioavailability

75%

Onset of action

15 minutes

Time to peak conc

30 minutes

Plasma half life

2 to 5 hours

Duration of action

less than 4 hours with a 5mg dose* (*individual variation)

  • As an antiepileptic agent, in single doses midazolam is considered to be twice as potent as diazepam.
  • As a sedative, in single doses midazolam is considered to be three times more potent than diazepam.
  • With multiple doses, diazepam gains in potency, relative to midazolam, because of a prolonged plasma half-life.

 

Side effects

  • As for other benzodiazepines.
  • Drowsiness and sedation (may persist for several hours after administration).
  • Respiratory depression in about 5% patients.

 

Dose and administration

  • 10mg buccally initially; repeated after 10 minutes if no effect and the patient is breathing normally. If no effect apparent 5 minutes after the second dose, seek medical help.
    Note: Consider a reduced dose (5mg) in elderly patients and patients under 50kg.
  • Using the oral syringe provided, administer over a period of 2 to 3 seconds, about half of the prescribed dose to each buccal cavity (between the gums of the lower jaw and the cheek). If the patient is very difficult to control, then administer the whole dose, over a period of 4 to 5 seconds, to one buccal cavity.
  • As a last resort, can be administered intra-nasally if the patient foams at the mouth.

 

Practice points

  • Midazolam is a Schedule 3 Controlled Drug (CD), therefore all prescriptions must satisfy CD prescription requirements to be valid and include details of the dose, form, strength, directions for use and total quantity (in both words and figures). Please refer to midazolam sample prescription in words and figures.
  • Patients on regular benzodiazepines who have developed a tolerance to their effects may require a higher dose.
  • An overdose can be treated with flumazenil (short-acting benzodiazepine antagonist).
  • Epistatus® is a licensed medicine for paediatrics in the pre-filled 10mg/ml  syringe only. All other preparations are unlicensed medications and as such have no marketing authorisation in the UK.
  • Epistatus® can be prescribed by the patient’s GP for the indications/uses listed in liaison with local palliative care specialists.
  • Patients should receive an initial supply on discharge to allow adequate time for the community pharmacist to order. The lead time for Epistatus® is approximately 4 working days.
  • Midazolam injection can be administered via the buccal route. The volume, however, is often impractical.

Patient and carer advice points

  • Buccolam® – remove oral syringe cap before use to avoid risk of choking.
  • Epistatus® (5ml bottle formulation) – the bottle cap must be replaced immediately to prevent evaporation. If the liquid is allowed to evaporate some of the midazolam will precipitate, exhibited as cloudiness or as white particles in the liquid. The pack must be discarded if the solution is not clear.
  • Do not store in a fridge.
  • Epistatus® (5ml bottle formulation) – the dose markings are on the syringe plunger not the syringe barrel.
  • Do not place the syringe between the patient’s teeth as they might bite the syringe.

 

References

Summary of Product Characteristics. Buccolam®. 2016 [cited 2018 Oct 04]; Available from: https://www.medicines.org.uk/emc/product/7460/smpc

Summary of product characteristics. Epistatus® 2017 [cited 2018 Oct 04]; Available from: https://www.medicines.org.uk/emc/product/2679

Dickman A, Schneider J. The Syringe Driver. 4th ed: Oxford University Press; 2016.

Royal Pharmaceutical Society. BNF - Midazolam. 2018 [cited 2018 Oct 04]; Available from: https://www.medicinescomplete.com/#/content/bnf/_776961889