Dextromethorphan, the active ingredient in over-the-counter cough and cold medications, may be used as a drug of abuse, particularly by adolescents. According to a 2006 study by the Partnership for a Drug Free America, one in 10 teens admitted to using dextromethorphan (DXM) to get high, leading to monitoring of DXM availability by the United States Department of Justice. While DXM overdose is rarely fatal, patients do need to be managed in the emergency department.
DXM Overdose: Signs and Symptoms
The effects of DXM are commonly described in phases. Phases 1 and 2 are comparable to the effects of alcohol and phencyclidine (PCP) intoxication, respectively. In Phases 1 and 2, DXM has a mild stimulant effect. Individuals with Phase 3 and Phase 4 ingestions need to be taken to the emergency department. When an individual cannot be roused, is conscious but not responsive, or drifts in and out of consciousness, these are signs of high dose ingestions and may indicate impending coma. Other alarming signs include slow, labored, shallow, or absent breathing; bluish fingernails or lips; blurred vision or jerky, uncoordinated eye movements; muscle spasms or twitching; poor balance or inability to walk; and vomiting.
Serotonin Syndrome: Signs and Symptoms
DXM overdose can also manifest as serotonin syndrome, which has slightly different symptoms compared to uncomplicated DXM overdose. DXM is a weak activator of the serotonin neurotransmitter system in the brain. When the serotonin system is overwhelmed, the signs and symptoms of serotonin syndrome emerge. These include altered mental status; seizures; muscle stiffness or rigidity; fever; and unstable heart rate, respiratory rate, and blood pressure. Without treatment, serotonin syndrome is fatal. Serotonin syndrome is more common in individuals who are also taking other drugs that affect serotonin levels. Examples include certain kinds of antidepressants (selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, and tricyclics), linezolid, meperidine, lithium, clonazepam, methylenedioxy-methamphetamine (MDMA, "ecstasy") and the dietary supplements tryptophan and St. John's wort.
Going to the Emergency Department
Individuals exhibiting symptoms of phase 3 or phase 4 DXM ingestion or serotonin syndrome need to be taken to the emergency department. Often, the interval between when a person begins to show symptoms and becomes unconscious is very short. Use this time to elicit information about the time and amount of ingestion, as well as any other drugs the person may be taking. Bring along the patient's wallet. A driver's license lists important information on age and weight. If possible, bring along the bottles or containers of DXM and any other drugs. Most over the counter formulas that contain DXM also contain other drugs such as acetaminophen or pseudoephedrine, and it is easier to manage an overdose if the drugs can be identified. DXM does not show up on standard drug screenings, although in some cases it may produce a false positive for phencyclidine (PCP).
References
- Drug Free Partnership of America Dextromethorphan Abuse
- American Association of Poison Control Centers
- Journal of the American Pharmacy Association. Dextromethorphan abuse: clinical effects and management. Romanelli F, Smith KM. March-April 2009
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