Dextromethorphan overdose

Betschart, T. et al., Dose-dependent toxicity of dextromethorphan overdose, Clin. Toxicol., 38,190,2000. 

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. 

Dextromethorphan Overdose. MEDLINEplus Medical Encyclopedia. . 

Intentional dextromethorphan overdose has caused two deaths (SEDA-17, 210). Dextromethorphan toxicity occurred in a 3-year-old child who ingested up to 270 mg. The effects were reversed by naloxone (2). 

Overdosing causes stupor and coma. Pulmonary edema occurs, and froth can be seen coming from the nose and mouth. An antidote for an opioid overdose is naloxone (Nar-can ), which can rapidly displace the opioid from the receptor. Overuse of dextromethorphan can induce euphoria, sedation, ataxia, increased awareness, sweating, elevated blood pressure, arrhythmia, hallucinations, and coma. Some of the dextromethorphan effects resemble those of phencyclidine. 

There is increasing concern over the street abuse of dextromethorphan, which is available in a variety of products. There have been a few reports of abuse and a handful of case reports of overdose and death. Nevertheless, dextromethorphan was specifically left out of the Controlled Substances Act (CSA) of 1970 and has not been added to the Drug Enforcement Administration (DEA) scheduling process despite these reports. This decision was made because dextromethorphan is not considered a narcotic and is generally thought to have a low addiction potential. However, the DEA is monitoring dextromethorphan and may add it to its list of controlled substances at some point in the future. 

Dizziness may occur in a small proportion of cases when dextromethorphan is used therapeutically. Mental confusion and central nervous system overstimulation may occur when there is an overdose of the drug. When dextromethorphan is abused, there is an increased risk of motor impairment that could affect activities that require quick judgment and reaction, such as operating heavy machinery. 

Boeckx RL. False positive EMIT DAU PCP assay as a result of an overdose of dextromethorphan. Clin Chem 1987 33 974-5 (abstract). 

I. Mechanism of toxicity. Dextromethorphan is the d-isomer of 3-methoxy-A/-methylmorphinan, a synthetic analog of codeine. (The Fisomer is the opioid anai-gesic levorphanol.) Although it has approximately equal antitussive efficacy as codeine, dextromethorphan has no apparent analgesic or addictive properties and produces relatively mild opioid effects in overdose. 

C. Seizures are not common after opioid overdose but occur occasionally with certain compounds (eg, dextromethorphan, meperidine, propoxyphene, and tramadol). Seizures may occur in patients with renal compromise who receive... 

Four patients died after taking moclobemide and ecstasy (MDMA, methylenedioxymethamfetamine). The clinical evidence is limited, but in each case the forensic pathologist concluded that the cause of death was the combined use of these drugs. It was suggested that what happened is consistent with the serotonin syndrome, although the evidence is fairly slim. Two patients had taken maximum therapeutic doses and two moderate overdoses of moclobemide. Note that moclobemide had not been prescribed to any of them. Post-mortem analysis also found the presence of dextromethorphan in one patient, which was thought to have contributed, see also MAOIs or RIMAs -i- Dextromethorphan , p.ll34. 

The contribution of dextromethorphan and chlorphenamine to the development of serotonin toxicity has been reviewed, and the authors also described a case of serotonin toxicity after ingestion of 48 cough tablets containing dextromethorphan 30 mg and chlorphenamine 4 mg There was no evidence that either drug alone was associated with toxicity, and the combination could have contributed to serotonin toxicity, especially in the context of an overdose. 

The authors included a systematic review of the serotonergic properties of chlorphenamine and concluded that overdose with medications that contain chlorphenamine and dextromethorphan may cause cumulative serotonergic effects resulting in significant serotonin toxicity. 

---