Dextromethadone

Dextromethorphan (DXM or DM) is a medication most commonly used as a cough suppressant in over-the-counter cold and cough medicines. It is used to relieve coughing caused by the common cold, bronchitis, and other breathing illnesses. This drug is available in syrup, tablet, spray, and lozenge forms. Dextromethorphan acts on the brain to increase the threshold for coughing. It is in the morphinan class of medications with sedative, dissociative, and stimulant properties (at higher doses).

Medical Uses

Dextromethorphan is primarily used to treat coughs due to colds or influenza. It is not effective in treating cough caused by smoking, asthma, or emphysema. DXM has also been found to have several off-label uses including the management of pain, psychiatric disorders, and neurological disorders, although these uses are less common and require more research.

Adverse Effects

Common adverse effects of dextromethorphan include dizziness, nausea, and drowsiness. At high doses, DXM can produce effects similar to those of ketamine and phencyclidine (PCP), including hallucinations, dissociation, and euphoria. Abuse of dextromethorphan, particularly among teenagers, is a concern due to its psychoactive effects when taken in large quantities.

Pharmacology

Dextromethorphan acts as a sigma-1 receptor agonist and a non-competitive NMDA receptor antagonist. It is metabolized in the liver by the enzyme CYP2D6 into dextrorphan, which is the compound responsible for most of dextromethorphan's cough suppressant effects. Variability in the CYP2D6 enzyme among individuals can lead to differences in response to dextromethorphan.

Chemistry

Dextromethorphan is a synthetic compound and is the dextrorotatory enantiomer of levomethorphan, which is an opioid analgesic. It is chemically related to codeine, but has a distinct structure that significantly reduces its potential for abuse and dependence.

History

Dextromethorphan was approved by the FDA in 1958 as a cough suppressant. Its discovery was part of an effort to find a non-addictive substitute for codeine. Over the years, DXM has become one of the most widely used cough suppressants in the United States and around the world.

Society and Culture

Legal status varies by country, but dextromethorphan is generally available over the counter in many places. However, due to concerns about abuse, some countries have restricted its sale to behind the counter, or require identification for purchase.

See Also

• Cough medicine
• NMDA receptor antagonist
• Recreational use of dextromethorphan