Edrophonium Intravenous for Adults

Who can administer

Registered competent doctor or nurse/midwife

Important information

  • Has been unavailable in UCHG for many years - due to manufacturing problems
  • Unlicensed preparation
  • Atropine injection must be available when edrophonium is being used to avoid severe muscarinic reactions, which may be fatal (ref 2)
  • Facilities for resuscitation should always be available
  • Use with extreme caution in patients with asthma

Available preparations

Edrophonium 10mg per 1ml ampoule (Alliance pharmaceuticals)

Edrophonium 25mg per 2ml ampoule (Anticude)

Enlon 150mg per 15ml multidose vial (10mg per ml)

Reconstitution

Already in solution

Ampoule: Draw up using a 5 micron filter needle

Methods of intravenous administration

Bolus intravenous injection

  • Administer required dose over 15 to 30 seconds (ref 1)
  • See under Dose for details

Dose in adults

Diagnostic test for myasthenia gravis (ref 1)

  • Dosing in prescribing information may not reflect current clinical practice
  • Methods vary in regards to the initial and repeat doses
  • However, all regimens utilise a maximum cumulative dose of 10mg and emphasise that the incremental administration is to help avoid excessive muscarinic side effects
  • Give 1mg test dose; if after 60 seconds there are no adverse effects, then administer 3mg. If after 60 seconds there is no improvement, then administer an additional 3mg; after an additional 60 seconds, repeat a 3mg dose if necessary for a total of 10mg

Evaluation of treatment requirements in myasthenia gravis(ref 1)

  • Give 1 to 2mg dose one hour after oral dose of anticholinesterase
  • Response will be myasthenic in the undertreated patient
  • Response will be adequate in the controlled patient
  • Response will be cholinergic in the overtreated patient

Monitoring

  • Monitor muscle strength pre- and post-injection (cranial musculature is most useful) (ref 2)
  • Monitor heart rate, respiratory rate and blood pressure (ref 2)

Further information

  • IV route preferred (ref 1)
  • In patients with inaccessible veins, dose for intramuscular injection is 10mg
  • When given by intramuscular route, the onset of action is 2 to 10 minutes (IV is 30 to 60 second)(ref 1)

Storage

Store below 250C 

References

UK SPC July 2010

1: Uptodate accessed online 7th Dec 2021

2: Injectable medicines guide. Medusa. Downloaded 7th Dec 2021

3: Martindale- accessed online 7th Dec 2021

Therapeutic classification

Diagnostic agent