The drug disulfiram (Antabuse) is a useful deterrent against further drinking when taken by mouth. An oral dose of one 200 mg tablet daily generally provides, after the drug has been consumed for a few days, enough of the substance in the body to produce an unpleasant and alarming reaction if alcohol is then consumed. The features of the disulfiram-ethanol reaction (DER) include headache, generalized flushing, malaise, dyspnoea, palpitations and vomiting; hypotension and tachycardia are also present. Cardiovascular collapse can ensue in severe reactions; fatalities have occurred in exceptional instances, so their possibility must be explained to thepatient before prescribing disulfiram. However, the DER is not usually too severe. Indeed, If a reaction does notensue if alcohol is taken it is appropriate to raise the daily dose of disulfiram to 400mg.
Side-effects from disulfiram can develop without alcohol. Serious ill effects, requiring immediate cessation of the drug., are peripheral neuritis, convulsions or psychosis; they are rare. More common side-effects are drowsiness, nausea and anorexia, depression, headaches and impotence. Drowsiness may he counteracted by taking the drug at night; if one of the other effects is persistent a change of medication can be made to citrated calcium carbimide (Abstem), in a dose of one or two 50 mg tablets daily.
The major difficulty with oral deterrents against drinking is that of gaining patient compliance. Alcoholics who are prescribed disulfiram may not start the medication; more frequently they stop it prematurely.
Sometimes cessation of the drug arises from the intention to resume taking alcohol; in other instances it stems from apathy or from confidence that abstention can he maintained by other means. Many alcoholics are indeed able to avoid drinking through measures that do not involve disulfiram or calcium
carbimide, but deterrent medication is a useful adjunct to therapy, particularly in the early stages of abstinence.
An alternative method of administration takes the form of the subcutaneous or intramuscular implantation of sterile pellets of disulfiram. They are available under the trade name Esperal. The procedure was introduced over 20 years ago in France and is extensively practiced at the present time in Poland.
Ten 100 mg pellets are provided in a glass container. Using general anaesthesia or regional infiltration by a local anaesthetic 8 to I0 pellets are implanted in a single operation, usually into the abdominal wall. The pellets can be placed within a muscle (eg between the fibers of rectus abdominis), but because the pellets lie directly under the skin incision, intramuscular insertion entails an enhanced risk of local irritation, sepsis and extrusion of pellets. It is preferable to use the method outlined by Whyte and 0‘Brien. An incision of 10 to 15 mm is made in the left iliac fossa down to subcutaneous fat and the pellets inserted through a special trochar and cannula in four radial directions at a distance 10 cm