Seizure - Medication

Disclaimer

These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline. 

Read the full PCH Emergency Department disclaimer.

Aim

To guide staff with the use of seizure medications in the Emergency Department.

Preparation

  • Prepare infusion immediately before use and discard if not commenced within 30 minutes of preparation. Do not prepare more than required dose.
  • Check for haziness or precipitation before and throughout the infusion.
  • Compatibility note: Phenytoin sodium is ONLY compatible with sodium chloride 0.9%. Do not administer with any other drugs or fluids.

Flushing Lines

  • Flush IV lines before and after Phenytoin sodium administration with sodium chloride 0.9%.
  • After the drug is given, give the flush at the same rate as the infusion.  The volume of flush must be sufficient to clear the line of all remaining drug.

 

Monitoring patients receiving IV phenytoin sodium, phenobarbital (phenobarbitone) and levetiracetam

  • Infusion rates are different in ward areas – refer to PCH Medication Monographs (WA Health only).
  • For the loading dose monitor BP, continuous ECG, pulse and respiration every five minutes during the infusion and for 30 minutes after completion of the flush.
  • If bradycardia or hypotension occurs, stop the infusion and call the doctor.  Consider recommencing the infusion at a lower rate.  

Seizure medication preparation 

Drug Route
Diluent Volume of Diluent
Dose Precautions
Midazolam (WA Health only)
(vial strength 5mg/mL)
Buccal Nil Neat 0.3mg/kg

Maximum 
10mg/dose


Midazolam (WA Health only
(vial strength 5mg/mL)
Intravenous
Intraosseous
Sodium chloride 0.9% Draw up 2mL of midazolam (10mg) and add 8mL sodium chloride 0.9% to give 10mg in 10mL (1mg/mL) 0.15mg/kg

Maximum 10mg/dose

 
Midazolam (WA Health only
(vial strength 5mg/mL)
Intramuscular Nil Neat 0.15mg/kg Consider muscle site appropriate to the age of child and volume to be administered
Diazepam (WA Health only)
(vial strength 5mg/5mL) 

Rectal  Nil  Neat  0.5mg/kg

Maximum 20mg/dose
 
Diazepam (WA Health only)
(vial strength 10mg/2mL) 

Intravenous
Intraosseous

Nil Neat 0.25mg/kg

Maximum 10mg/dose
Over at least 3 to 5 minutes
Paraldehyde (WA Health only)
(vial volume 5 mL)
Rectal Olive oil
Dilute 1:1
(1 part paraldehyde to 1 part diluent)

0.4mL/kg (rectal)

Maximum 10mL/dose
Can be prepared in plastic syringe if given immediately

Avoid IM / IV administration
Clonazepam
(vial strength 1mg/mL) 

                        

Intravenous Use diluent provided (ampoule) Mix 1mg ampoule with 1 mL of diluent to give a 0.5mg/mL solution

0.05mg/kg 
Repeat after 15 minutes if necessary

Maximum 1mg/dose

 

Over at least 2 minutes

Can cause respiratory depression especially if given quickly or combined with barbiturates or other benzodiazepines

Intravenous infusion preparation

Drug

Diluent

Volume of Diluent

Rate of Administration

Precautions and Side Effects

Phenytoin sodium (WA Health only)
(IV loading dose)
20mg/kg
Max dose = 1.5g
Sodium chloride 0.9%
(not compatible with glucose or other drugs, insert 2nd IV line)
 

Children ≤ 30kg
100mL
(add drug directly into a 100mL bag of sodium chloride 0.9%)

Children > 30kg
250mL 
(add drug directly into a 250mL bag of sodium chloride 0.9%)

 
 
20 minutes in ED only
(controlled using an infusion pump)
 
  • See above for flushing lines and monitoring requirements.
  • Take into account any Phenytoin received recently (including orally)
  • Do not prepare more than the required amount
  • Line must be flushed before and after with sodium chloride 0.9% 
  • ECG and BP monitoring is essential
  • Reduce the rate of administration if bradycardia or hypotension develop
Phenobarbital (WA Health only)
(Phenobarbitone)
(IV loading dose)
20mg/kg
Max dose =1g

 
Sodium chloride 0.9% 
or
Glucose 5% 
 
Dilute to 20mg per 1mL of diluent Over 20 minutes
  • Respiratory depression
  • Hypotension
  • Incompatible with many drugs
  • Avoid extravasation
  • Effects are potentiated by concurrent use of other barbiturates or benzodiazepines
Midazolam (WA Health only)
(continuous infusion)
Sodium chloride 0.9%  
or 
Glucose 5%
 

Midazolam 2.5mg/kg (max 125mg) in 50mL of diluent.

(a rate of 1 mL per hour  =
Child ≤ 50kg: 50 microgram/kg/hour
Child > 50kg: 2.5mg/hour)

50-250 microgram/kg/hr
  • Should be used in ventilated patients in intensive care unit
Levetiracetam
(IV loading dose)
40mg/kg 
Max dose = 3g

 
0.9% Saline 
or 
5% Glucose
Sodium chloride 0.9% Infuse over 5 minutes
  • Incompatible with many drugs

References

  1. AMH Children’s Dosing Companion (2020) Australian Medicines Handbook Pty Ltd
  2. Australian Injectable Drugs Handbook (AIDH) - 8th Edition 2020

 


Endorsed by:  Drug and Therapeutics Committee  Date:  Jul 2020


 Review date:   Jul 2023


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