Disulfiram

Disulfiram is a medication used to treat chronic alcoholism. It is sold under the brand names Antabuse and Antabus.
Disulfiram works by making people feel very sick if they drink alcohol. It is not a cure for alcoholism. Usually, alcoholics who take disulfiram also need to get counseling and support.
Effects.
When a person gets treatment for alcoholism, disulfiram may be part of their treatment plan. However, the person has to go through alcohol withdrawal first. It is not safe to take disulfiram if a person has had any alcohol in the past 12 hours.
When a person takes disulfiram, they get very sick if they drink any alcohol. They will start feeling sick 5 to 30 minutes after they drink. Usually, the more a person drank, the sicker they will feel. Their symptoms may include:
These symptoms can last anywhere from a half hour to a few hours.
Problems.
Cravings.
One of the symptoms of alcoholism is wanting alcohol very, very badly. This is called craving. An alcoholic feels like they need alcohol to live.
One problem with disulfiram is that it does not stop alcohol cravings. If an alcoholic takes disulfiram, they will keep craving alcohol, but will get very sick if they do drink. Many alcoholics solve this problem by just not taking disulfiram. One year-long study done in 1986 found that disulfiram did not seem to work. However, the researchers found that only 20% of the alcoholics actually took their disulfiram. The other 80% stopped taking disulfiram so they could drink alcohol without getting sick. 
However, later studies found that when disulfiram is supervised - when someone watches an alcoholic take their disulfiram - the medication works. Alcoholics getting supervised disulfiram drink less, go longer periods of time without drinking, and participate more in other treatments than alcoholics getting un-supervised disulfiram. Family members, friends, clinics, or courts can make sure that alcoholics take their disulfiram.
Disulfiram tablets can also be placed under the skin by a surgeon. These tablets release disulfiram continuously for up to 12 weeks. This makes it impossible for an alcoholic to decide not to take their disulfiram so they can drink.
Also, a doctor can prescribe a newer drug, like naltrexone, along with disulfiram. Naltrexone does block alcohol cravings. The two drugs can work together to make it easier for the alcoholic not to drink.
Not a cure.
The United States National Institutes of Health says:
"Disulfiram is not a cure for alcoholism. When [disulfiram is] used alone, without proper motivation and supportive therapy, it is unlikely that it will have any [real] effect on the drinking pattern of the chronic alcoholic."
Just taking disulfiram is usually not enough to keep an alcoholic from drinking. Disulfiram works best when an alcoholic also:pp. 130–144
Other uses.
Disulfiram may help other medical problems too. It kills some parasites that can cause infectious diseases.
Researchers are also studying whether disulfiram could treat cancer, HIV, and cocaine addiction.