Section 3.6.3

Disulfiram

General Description

Disulfiram (Antabuse) is an acetaldehyde dehydrogenase inhibitor that blocks the oxidation of alcohol at the acetaldehyde level. Accumulation of acetaldehyde in the blood produces complex highly unpleasant symptoms. These symptoms include flushing, throbbing of head and neck, throbbing headache, respiratory difficulty, nausea, copious vomiting, sweating, thirst, chest pain, palpitation, dyspnea, hyperventilation, tachycardia, hypotension, syncope, marked uneasiness, weakness vertigo, blurred vision and confusion. These symptoms persist as long as the alcohol is metabolized in the body. Disulfiram does not influence the rate of alcohol elimination from the body.

Indication for Medication

Disulfiram may be used as an aid in the management of selected chronic alcoholic patients who want to remain in a state of enforced sobriety so that supportive and psychotherapeutic treatment may be applied to best advantage.

Alcoholic patients that profess a desire to stop drinking benefit from disulfiram therapy because they know the effects of disulfiram remains for up to a week after having stopped taking it. In this way, a relapse must be "planned" rather than impulsively occurring. If an impulsive "slip" does occur, the presence of disulfiram produces a sensitivity to alcohol which results in a highly unpleasant reaction.

Disulfiram has been used in some cases as part of a court ordered diversion program. In those situations, the ingestion of the medication was witnessed and documented.

Clinical Guidelines

For most individuals, the knowledge that highly unpleasant symptoms will occur prevents them from using alcohol. However, some individuals do deliberately consume alcohol or accidentally use an alcohol-containing product. In those cases, the intensity of the reaction between disulfiram and alcohol varies. In extreme cases, respiratory depression, cardio-vascular collapse, myocardial infarction, convulsions and death may occur.

Disulfiram should never be administered until the patient has abstained from alcohol for at least l2 hours. The usual initial dose taken by mouth is 500mg a day for first one to two weeks, followed by a maintenance dosage of l25 to 500mg a day.

Disulfiram should be used with caution in patients with diabetes mellitus, hypothyroidism, epilepsy, cerebral damage, chronic and acute nephritis, hepatitis, cirrhosis or hepatitic insufficiency. The safe use of disulfiram in pregnancy has not been established. Patients should carry an identification card stating that patient is receiving disulfiram, possible symptoms, physician's name or institution to contact in case of an emergency.

Since barbiturates and disulfiram can be used together, development of new addiction should be kept in mind. Baseline and follow up transaminase levels within 10-14 days will help detect hepatic dysfunction that may result from disulfiram therapy.

Disulfiram is contraindicated in the presence of severe myocardial disease or coronary occlusion, psychosis and hypersensitivity to disulfiram or to other thiouram derivatives used in pesticides and rubber vulcanization.

In severe reactions, whether caused by excessive test dose or by the patient's unsupervised ingestion of alcohol, supportive measures to restore blood pressure and to treat shock should be instituted.

Adverse Effects

Optic neuritis, peripheral neuritis, polyneuritis peripheral neuropathy may occur following administration of disulfiram. Multiple cases of hepatitis, including both choleostatic and fulminant hepatitis have been reported. In a small number of patients, a transient mild drowsiness, fatigability, impotence, headache, acneform eruptions, allergic dermatitis, metallic garlic like after taste may be experienced.

Drug-Drug Interactions

Patients taking disulfiram tablets should not be exposed to ethylene dibromide or its vapors. Patients should be warned to avoid alcohol in disguised form (i.e. sauces, vinegars, cough mixtures, aftershave lotion, back rubs.) Patients who are receiving or have recently received metronidazole, paraldehyde, alcohol, or alcohol containing preparations (e.g. cough syrup or, tonics) should not be given disulfiram.

The consent form for this medication is "Dual Diagnosis Medications."