Disulfiram is a drug used to treat alcohol dependence by producing unpleasant reactions when alcohol is consumed while taking the drug. It works by inhibiting the breakdown of acetaldehyde, causing levels to rise over 10 times higher than normal when alcohol is ingested and resulting in symptoms like flushing, nausea, and increased heart rate. The drug is usually taken daily in tablet form to discourage drinking and support abstinence during treatment. Side effects are generally mild but can include headaches and drowsiness.