Dextromethorphan is a cough suppressant, or antitussive, which acts on the brain to help stop the cough reflex. It is found in more than 100 over-the-counter (OTC) medications such as Robitussin, Coricidin and Vicks products. Besides the intended use for suppressing coughs due to colds and influenza, the medication is used as a recreational drug where proper dosage and short-term use may be ignored. Short-term side effects may include hallucinations, dizziness, nausea, difficulty breathing, acute toxic effects and disorientation. Long-term effects may include permanent organ damage and even death.
Liver Damage
Dextromethorphan is often combined with acetaminophen, which can severely damage the liver if taken in high doses, according to the Partnership for a Drug-Free America website. Prolonged use only increases the likelihood of liver damage.
Cognitive Deterioration
Decreased cognitive ability is one possible long-term effect, reports the National Institutes of Health website. A University of Western Ontario study reported in a 1994 issue of the "Journal of Psychiatry and Neurosciences" that prolonged abuse of the drug caused deterioration of cognitive ability in a 30-year-old male subject. Although anecdotal and isolated, it is unusual to get data on a long-term, chronic user, and the effects were thought to be important because the drug had been thought to be quite safe.
Death
Death is one long-term effect of taking dextromethorphan in dosages too high or by patients too young, according to RxList.com. The website states that overdoses and deaths have been reported when caregivers gave too much of the drug to "very small children." While a 15 to 30mg dose might be safe, overdoses of more than 100mg can both impair thinking and become toxic. Nausea, vomiting, seizures and paranoia have all been results of such overdoses.
Hallucinations and Self-Harm
Between 2000 and 2003, overdoses of dextromethorphan more than doubled, according to RxList.com. Also called "DXM," teens using the drug recreationally have shown dissociative symptoms, including "memory loss, depression, anxiety, detachment from self, sense of unreality and a blurred sense of identity," according to the website.
