Search The Medical Knowledge Base

Drug Details

Edrophonium

• Drug Class Description
  Anticholinesterases.
• Generic Name
  Generic
• Presentation
  Ampoules
• Description
  Each ampoule contains 10mg Edrophonium Chloride BP in 1ml of solution.
• Indications
  Myasthenia gravis, as a diagnostic test; to distinguish between overdosage and underdosage of cholinergic drugs in myasthenic patients; diagnosis of suspected 'dual block'; antagonist to non-depolarising neuromuscular blockade.
• Adult Dosage
  

  Edrophonium Injection BP is for intramuscular or intravenous injection. In view of the possibility of provoking a cholinergic crisis it is recommended that facilities for resuscitation should be available whenever Edrophonium Injection BP is administered.

  Adults - Test for myasthenia gravis:

  A syringe is filled with the contents of 1 ampoule (10mg) and 2mg is given intravenously, the needle and syringe being left in situ. If no response occurs within 30 seconds, the remaining 8mg is injected. In adults with unsuitable veins, 10mg is given by intramuscular injection.

  To differentiate between 'myasthenic' and 'cholinergic' crises:

  In a myasthenic patient who is suffering from marked muscle weakness, in spite of taking large doses of Mestinon or Prostigmin, a test dose of 2mg Edrophonium Injection BP is given intravenously one hour after the last dose of the cholinergic compound. If therapy has been inadequate, there is a rapid, transient increase in muscle strength; if the patient has been overtreated, Edrophonium Injection BP causes a transient increase of muscle weakness.

  Diagnosis of suspected 'dual block':

  Edrophonium Injection BP 10mg intravenously. If the block is due to depolarisation, it is briefly potentiated, whereas in a 'dual block', it is reversed.

  Children: Diagnostic tests:

  A total dose of 100micrograms/kg body-weight may be given intravenously. One fifth of this dose should be injected initially; if no reaction occurs, the remainder of the dose is administered 30 seconds later.

  Antagonist to non-depolarising neuromuscular blockade:

  Generally, reversal of neuromuscular block with Edrophonium Injection BP should not be attempted until there is evidence of spontaneous recovery from paralysis. It is recommended that the patient be well ventilated and a patent airway maintained until complete recovery of normal respiration is assured.

  Adults and children:

  Edrophonium Injection BP 500 - 700micrograms/kg body-weight and atropine 7micrograms/kg body-weight, by slow intravenous injection over several minutes, is usually adequate for reversal of non-depolarising muscle relaxants within 5 - 15 minutes. The two drugs are usually given simultaneously, but in patients who show bradycardia the pulse rate should be increased to about 80/minute with atropine before administering Edrophonium Injection BP.

  The speed of recovery from neuromuscular blockade is primarily determined by the intensity of the block at the time of antagonism but it is also subject to other factors, including the presence of drugs (eg. anaesthetic agents, antibiotics, antiarrhythmic drugs) and physiological changes (electrolyte and acid-base imbalance, renal impairment). These factors may prevent successful reversal with Edrophonium Injection BP or lead to recurarisation after apparently successful reversal. Therefore it is imperative that patients should not be left unattended until these possibilities have been excluded.

   

• Child Dosage
  Detection of over or under dosage with cholinergic drugs, 20 micrograms/kg. If no adverse reaction occurs, 80 micrograms/kg dose 30 seconds later.
• Elderly Dosage
  

  There are no specific dosage recommendations for Edrophonium Injection BP in elderly patients.

• Contra Indications
  

  Edrophonium Injection BP should not be given to patients with mechanical intestinal or urinary obstruction.

  Edrophonium Injection BP is contra-indicated in patients with known hypersensitivity to the drug.

• Special Precautions
  

  Extreme caution is required when administering Edrophonium Injection BP to patients with bronchial asthma.

  Care should also be taken in patients with bradycardia, recent coronary occlusion, vagotonia, hypotension, peptic ulcer, epilepsy or Parkinsonism.

  In diagnostic uses of Edrophonium Injection BP, a syringe containing 1mg of atropine should be kept at hand to counteract severe cholinergic reactions, should they occur. In view of the possibility of provoking a cholinergic crisis it is recommended that facilities for resuscitation should always be available.

  When Edrophonium Injection BP is used as an antagonist to neuromuscular blockade bradycardia may occur, to a possibly dangerous level, unless atropine is given simultaneously. In this indication, Edrophonium Injection BP should not be given during cyclopropane or halothane anaesthesia; however, it may be used after withdrawal of these agents.

  There is no evidence to suggest that Edrophonium Injection BP has any special effects in the elderly. However, elderly patients may be more susceptible to dysrhythmias than younger adults.

• Interactions
  

  With doses above 10mg, especially the higher dosage employed to antagonise neuromuscular blockade, Edrophonium Injection BP should not be used in conjunction with depolarising muscle relaxants such as suxamethonium as neuromuscular blockade may be potentiated and prolonged apnoea may result.

• Adverse Drug Reactions
  

  These may include nausea and vomiting, increased salivation, diarrhoea and abdominal cramps