Practical aspects of use of disulfiram in alcohol detoxification

• disulfiram should be considered in motivated patients at an early stage in preparation prior to detoxification
  • there are significant risks associated with the use of disulfiram and staff must be competent to discuss these risks with the patient. These include contraindications, most importantly heart disease (active or in the past 6 months, or tendency to cardiac arrhythmia), and interactions
    
    
• prescribing disulfiram should follow a physical review, including LFTs (exclude if bilirubin >25mmols and/or GGT >10 times normal and/or ALT or Alk Phos > twice normal) (1). An ECG may be required if cardiac history is uncertain
  
  
• ideally the patient should be able to identify a carer to supervise the medication to enhance treatment adherence and efficacy, or it can be supervised by the pharmacist, with prior agreement
  
  
• disulfiram works by preventing the breakdown of alcohol by irreversibly blocking the enzyme acetaldehyde dehydrogenase
  • if alcohol of any kind is consumed by an individual taking disulfiram, within 10-15 minutes they will experience an unpleasant reaction mediated by the build-up of acetaldehyde characterised by facial flushing, headache, palpitations, tachycardia, dyspnoea, nausea and vomiting
    • if large doses of alcohol are taken the reaction can progress to hypotension, arrhythmias and collapse
    • a reaction to disulfiram can last for several hours. The severity of the reaction varies between individuals some having severe and occasionally life-threatening reactions, others having mild or no reaction at standard doses (the latter group may require higher doses)
    • all those prescribed the medication should be given a patient advice leaflet warning against sources of "hidden" alcohol such as Christmas pudding, liqueur chocolates, and even certain cosmetic products
    • disulfiram works by changing the expectancy of the effects of alcohol from positive and rewarding to negative and aversive. The action of disulfiram lasts for 7 days after the last dose. The patient must be warned that they will not be able to drink safely for this period.
    • treatment is usually for 6-12 months but may be longer, if required. Dosage 200mg/day, or 400mg on alternate days, but occasionally individuals require doses as high as 600mg per day (1)

Reference:

• 1) SMMGP (February 2010). Network;28:12-14.