Dextromethorphan (DXM) is a common over-the-counter medication used as a cough suppressant. It is found in many cold and flu remedies and is classified as an antitussive. Dextromethorphan works by affecting the signals in the brain that trigger the cough reflex.
Pharmacology and Mechanism of Action
Dextromethorphan is a
non-opioid derivative of morphine. It acts as an antagonist to the
N-methyl-D-aspartate (NMDA) receptor and also has affinity for serotonin transporters. This dual action is responsible for its antitussive properties. Additionally, dextromethorphan's effect on the NMDA receptor is similar to that of dissociative anesthetics, which explains its potential for abuse.
Therapeutic Use
Primarily, dextromethorphan is used to relieve
cough symptoms associated with a cold or the flu. It is available in various forms, including syrups, tablets, and lozenges. Despite its efficacy in cough suppression, it does not treat the underlying cause of cough or speed recovery from an illness.
Risk of Abuse and Toxicity
Dextromethorphan has been increasingly misused for its psychoactive effects, particularly among adolescents. At high doses, it can produce dissociative and hallucinogenic effects similar to those of
ketamine or
PCP. This misuse is often referred to as "robotripping" or "skittling."
Overdose can lead to serious toxicological effects, including confusion, dizziness, nausea, increased heart rate, and in severe cases,
seizures or
coma. Chronic abuse may also cause cognitive impairments and psychological dependence.
Metabolism and Excretion
Dextromethorphan is metabolized in the liver by the
cytochrome P450 enzyme CYP2D6 into its active metabolite, dextrorphan. Individual variations in CYP2D6 activity can lead to differences in how people experience the drug's effects. For instance, poor metabolizers may experience exaggerated effects even at low doses, increasing the risk of toxicity.
Legal and Regulatory Status
In many countries, dextromethorphan is available over the counter without a prescription. However, due to its potential for abuse, some regions have implemented age restrictions or require identification upon purchase. Efforts to regulate its sale aim to reduce misuse and prevent toxic exposure, particularly among young individuals.
Management of Overdose
In cases of dextromethorphan overdose, immediate medical attention is crucial. Treatment typically involves supportive care, including monitoring vital signs and administering activated charcoal to limit absorption if the ingestion is recent. In severe cases, benzodiazepines may be used to manage seizures, and intravenous fluids can help maintain hydration and electrolyte balance.
Prevention Strategies
Preventing dextromethorphan abuse involves education and awareness campaigns aimed at informing the public, especially teenagers, about the risks associated with misuse. Parents, educators, and healthcare providers play key roles in monitoring for signs of abuse and encouraging safe use of medications.
Additionally, pharmacists can provide guidance on appropriate usage and discuss potential side effects with consumers to mitigate risks effectively.
