Dextromethorphan: An oral cough suppressant available in the US without a prescription but which is sometimes abused as a recreational drug. Dextromethorphan (DXM) is chemically related to codeine and acts on the brain to suppress cough, but it does not have the pain relieving and addictive properties of codeine. DXM is an ingredient in more than 125 nonprescription cough and cold medications, including forms of Robitussin, Coricidin and Vicks.
Cough and cold medications containing DXM are popular among teenagers and young adults looking for a high. Overdoses with DXM doubled from 2000 to 2003 in the US. DXM is safe in the 15- to 30-milligram doses recommended for treating coughs or colds. But in large doses (eg 100 milligrams or more), DXM can cause hallucinations and feelings of unreality.
The signs of DXM abuse include confusion, impaired judgment, blurred vision, dizziness, paranoia, excessive sweating, slurred speech, seizures, fever, and nausea and vomiting. In some cases, overdoses and deaths have occurred when caregivers have given cough or cold medications containing DXM to very small children in inappropriate large doses.