Dextromethorphan: Physiological effects
Last modified: Saturday, 30. May 2009 - 3:38 pm
Dextromethorphan produces effects centrally at the cough center to raise the threshold for coughing. Researchers have also proposed that dextromethorphan has important interactions with compounds in the brain that have excitatory effects. Some researchers believe that dextromethorphan may eventually be used as a drug to protect the brain against strokes and bacterial meningitis. However, the Food and Drug Administration (FDA) has not yet approved dextromethorphan for these uses.
Researchers have determined that dextromethorphan is approximately equal to codeine in cough-suppressing ability. Dextromethorphan is rapidly absorbed from the gastrointestinal tract of the body where it is metabolized by the liver and then mostly excreted in the urine. Dextromethorphan begins to exert its effects within 15 to 30 minutes. The duration of the drug’s action is about three to six hours.
Dextromethorphan has been placed in the FDA pregnancy category C, meaning that it has yet to be determined whether this drug can harm an unborn baby. Pregnant women should not take this drug without first consulting their physician. Researchers do not yet know if dextromethorphan passes into the breast milk in the nursing mother. Dextromethorphan cannot be detected by using any currently available urine screening techniques or during a standard clinical examination.
Harmful side effects
Significant side effects are extremely uncommon with dextromethorphan when it is taken at therapeutic levels. However, dizziness and nausea can occur in a small proportion of cases. Like most drugs, dextromethorphan can be dangerous when taken at levels above the therapeutic range. In such cases, central nervous system over-stimulation can occur. Conversely, mental confusion can occur in these cases. Extremely high doses can lead to respiratory depression. Young people are increasingly abusing dextromethorphan at nightclubs or “raves.” It is here where the drug is either mixed with, or substituted for, ecstasy. The combination of drug use and vigorous dancing has led to an increased number of reports of users developing heatstroke-like symptoms.
The intoxication syndrome associated with dextromethorphan tends to produce the following symptoms in the abuser: high blood pressure, clumsiness, disrupted speech, increased sweating, increased excitability, changes in eye movement, and fatigue. More general symptoms of overdose can include muscle spasticity in the body as a whole, slow and labored breathing, shallow breathing, pinpoint pupils, bluish tint to fingernails and lips, spasms in the gastrointestinal tract, low blood pressure, weak pulse, hallucinations, and drowsiness.
Emergency medical personnel should be contacted immediately if an overdose is suspected. If a poison control center suspects a dextromethorphan overdose, induced vomiting may be recommended. The usual home treatment involves the administration of ipecac syrup to induce vomiting.
Long-term health effects
No serious long-term effects are associated with the Therapeutic use of dextromethorphan. However, information has not been adequately collected on the health effects associated with the long-term abuse of dextromethorphan.