A few weeks ago we reported on a new study demonstrating that a drug called Nuedexta (containing dextromethorphan and quinidine) might ease some devastating complications of Alzheimer’s disease. A parent took us to task for not discussing the dangers of dextromethorphan.
Q. I am concerned about an article you wrote that mentioned the use of dextromethorphan for calming the agitation of Alzheimer’s disease. You said it is available in cough syrup.
My son read ten years ago about using cough syrup with “dex” to calm down. He tried it and has become a full-blown dextromethorphan addict. What started out as a small amount turned into bottles at a time.
He is now clinically diagnosed as mentally ill. Before cough syrup, he was functioning in a managerial position.
Your article did not warn readers about the dangers of misusing dextromethorphan. Cough syrup addiction destroyed my son’s life. Using this drug in any way other than its intended purpose should be strictly avoided.
A. Dextromethorphan is perceived as the safest and most effective cough medicine in America. It is sold over the counter as the “DM” or “DXM” in dozens of popular OTC cold and cough medicine. You will find dextromethorphan in Coricidin HBP, Dimetapp DM, Robitussin DM, Mucinex DM, Nyquil Cold & Flu, and dozens of other products.
The History of Dextromethorphan:
The cough medicine that most people used in the early 20th century often contained codeine. It was sold in low doses over the counter in most states and was partially effective at calming a cough. But some people abused codeine-containing cold remedies even though the dose was relatively low
Because the military and other government organizations feared codeine abuse and addiction, there was a search for a substitute cough medicine that would not pose an abuse potential. Dextromethorphan was approved by the FDA in 1958 and eventually became the go-to ingredient in most OTC cough remedies.
How Effective are DM Cough Medicines?
Given the widespread use of DM-containing cough remedies for so many decades it is shocking to discover that there are few well-controlled trials demonstrating effectiveness. An article in American Family Physician (Feb. 15, 2007) summarized the medical knowledge:
“Dextromethorphan may be beneficial in adults with cough, but its effectiveness has not been demonstrated in children and adolescents.”
Please note the use of the words “may be beneficial in adults with cough.” The authors were careful not to say is beneficial.
Another article in American Family Physician (July 15, 2012) notes under the heading:
Therapies Not Effective for the Common Cold in Children
“Dextromethorphan: Not superior to placebo in nocturnal cough or sleep quality in the child or parents”
Under the heading “Effective Interventions” the authors note that:
“Studies of dextromethorphan and guaifenesin [an expectorant] for cough are almost evenly split, with some demonstrating benefit and others not.”
The independent Cochrane Collaboration (Cochrane Database of Systematic Reviews, Oct. 18, 2004) analyzed all the available data from well-controlled clinical trials and concluded:
“There is no good evidence for or against the effectiveness of OTC medicines in acute cough.”
None of these assessments offers a ringing endorsement of dextromethorphan as a cough suppressant. One overview suggests that dextromethorphan has limited effectiveness at best, reducing coughs caused by colds by less than 20% (Chest, Jan., 2006)
The People’s Pharmacy Bottom Line on DM Effectiveness:
From our vantage point dextromethorphan appears to be barely better than placebo. Large, well-controlled trials spanning several days or weeks need to be done to establish whether this common ingredient reliably eases a cough for most people.
Dextromethorphan Dangers:
When the FDA approved dextromethorphan in 1958, the agency assumed it had solved the problems of codeine abuse. DM was thought to be a safe and nonaddictive cough suppressant.
Little did the FDA realize that “dex” or DXM posed unique problems. By 1975 there were clear signals that people were abusing this drug. It is considered a “dissociative anesthetic,” creating a sense of separation between mind and body.
At high doses the drug can cause altered perceptions, disorientation, dizziness, euphoria, increased energy, lethargy, hallucinations, alterations in the perception of time, hyperactivity, panic, nausea, vomiting, paranoia, insomnia, sweating, rapid heart rate, muscle spasms and blackouts.
Even in so-called normal doses, dextromethorphan may cause adverse reactions for some people.
Dextromethorphan Side Effects:
- Digestive upset, nausea, vomiting, constipation, diarrhea
- Skin reactions, rash, itching
- Drowsiness, fatigue, sedation
- Mental disorientation, confusion, anxiety
Your son’s tragic experience with “dex” is clear evidence that some lives have been ruined by this drug. Thank you for reminding us that there are some serious risks associated with dextromethorphan and that it should only be used in the recommended dose and for the intended purpose.
What About Dextromethorphan and Quinidine for Dementia?
The article that you were concerned about involved a prescription medicine called Nuedexta that was approved by the FDA in 2010 for treating a neurological condition called pseudobulbar affect (PBA). People with PBA experience uncontrollable inappropriate laughing or crying. It is a devastating brain disease.
Alzheimer’s disease is even more devastating for patients and their families. One of the more common complications of this dementia is agitation. It can manifest as verbal or physical abuse and is terribly distressing for caregivers. When the anxiety and agitation become too much to handle, patients with Alzheimer’s disease dementia often end up in a nursing home.
When staff members can no longer deal with the agitation they have been known to dose patients with Alzheimer’s disease with powerful antipsychotic medications. Drugs like aripiprazole (Abilify), haloperidol (Haldol), olanzepine (Zyprexa), risperidone (Risperdal) or quetiapine (Seroquel) were far too frequently dispensed to confused nursing home residents. Eventually the FDA became so concerned that it issued a black box warning (its strongest alert) that:
“Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death.”
Anything that can calm someone suffering from Alzheimer’s disease without causing them undue risks would be very welcome. That’s why there has been such interest in a recent study of patients suffering from Alzheimer’s disease agitation. The investigators found that Nuedexta could be helpful in reducing agitation and aggression (JAMA, Sept. 22/29, 2015). The FDA has not yet approved it for this use.
The ingredients in Nuedexta are quinidine, an old heart rhythm regulator, and dextromethorphan. The dose of dextromethorphan in Nuedexta is 20 mg, one third the dose recommended in an OTC product like Robitussin 12 Hour Cough Relief.
The Future of Dextromethorphan for Alzheimer’s Disease:
Given that the dose of DM in the prescription drug Nuedexta is substantially lower than that found in cough medications, we suspect that the risks of abuse that you described with your son are also much lower. If Nuedexta is approved by the FDA for treating the agitation and aggression of Alzheimer’s disease dementia, it will require careful oversight by a physician.
As the authors of an accompanying editorial in JAMA point out:
“Effective treatment options for agitation in patients with Alzheimer disease are limited, so clinical innovation in this area is a high priority.”
What’s your experience with dextromethorphan? Do you find it to be an effective cough suppressant? Are you concerned about abuse of this drug? Do you think it might offer benefits for people with Alzheimer’s disease dementia? Share your thoughts below and please vote on this article at the top of the page.
