Dextromethorphan poisoning: An evidence-based consensus guideline for out-of-hospital management

Cannabis and Other Substance Misuse: Implications and Regulations

Abusing controlled substances, including cannabis and various drugs, can result in severe intoxication and even death. Therefore, a comprehensive postmortem analysis is crucial for understanding the underlying causes of such fatalities. This narrative review discusses the characteristics of commonly abused controlled substances, the methodologies employed in postmortem analysis, lethal dosage levels, mechanisms of toxicity, side effects, and existing regulations. The focus centers on seven prevalent groups of controlled substances, namely cannabis, opioids, amphetamine-type stimulants, cocaine, new psychoactive substances, and hallucinogens. These groups have been linked to an increased risk of fatal overdose. Most substances in these groups exert neurotoxic effects by targeting the central nervous system (CNS). Consequently, strict regulation is essential to mitigate the potential harm posed by these substances. To combat abuse, prescribers must adhere to guidelines to ensure their prescribed medications comply with the outlined regulations. Through an enhanced understanding of controlled substance abuse and its consequences, more effective strategies can be developed to reduce its prevalence and associated mortality.

Classics in Chemical Neuroscience: Dextromethorphan (DXM)

Dextromethorphan (DXM) was introduced in 1958 as the first non-opioid cough suppressant and is indicated for multiple psychiatric disorders. It has been the most used over-the-counter cough suppressant since its emergence. However, individuals quickly noticed an intoxicating and psychedelic effect if they ingested large doses. DXM's antagonism at N-methyl-d-aspartate receptors (NMDAr) is thought to underly its efficacy in treating acute cough, but supratherapeutic doses mimic the activity of dissociative hallucinogens, such as phencyclidine and ketamine. In this Review we will discuss DXM's synthesis, manufacturing information, drug metabolism, pharmacology, adverse effects, recreational use, abuse potential, and its history and importance in therapy to present DXM as a true classic in chemical neuroscience.

High doses of dextromethorphan induced shock and convulsions in a 19-year-old female: A case report

BACKGROUND

Dextromethorphan is a prevalent antitussive agent that can be easily obtained as an over-the-counter medication. There has been a growing number of reported cases of toxicity in recent years. Generally, there are numerous instances of mild symptoms, with only a limited number of reports of severe cases necessitating intensive care. We presented the case of a female who ingested 111 tablets of dextromethorphan, leading to shock and convulsions and requiring intensive care that ultimately saved her life.

CASE SUMMARY

A 19-year-old female was admitted to our hospital via ambulance, having overdosed on 111 tablets of dextromethorphan (15 mg) obtained through an online importer in a suicide attempt. The patient had a history of drug abuse and multiple self-inflicted injuries. At the time of admission, she exhibited symptoms of shock and altered consciousness. However, upon arrival at the hospital, the patient experienced recurrent generalized clonic convulsions and status epilepticus, necessitating tracheal intubation. The convulsions were determined to have been caused by decreased cerebral perfusion pressure secondary to shock, and noradrenaline was administered as a vasopressor. Gastric lavage and activated charcoal were also administered after intubation. Through systemic management in the intensive care unit, the patient’s condition stabilized, and the need for vasopressors ceased. The patient regained consciousness and was extubated. The patient was subsequently transferred to a psychiatric facility, as suicidal ideation persisted.

CONCLUSION

We report the first case of shock caused by an overdose of dextromethorphan.

Life-threatening pediatric dextromethorphan polistirex overdose

Dextromethorphan polistirex is an extended-release formulation of dextromethorphan hydrobromide, marketed as Delsym® (Reckitt; Parsippany, NJ), with a duration of action roughly two to three times that of the standard formulation. The polistirex binder is responsible for the prolonged duration of action by slowing the release of active ingredient; the liberated dextromethorphan has unchanged pharmacokinetics and clinical effects. A 23-month-old male presented following a 900 mg (71.4 mg/kg) dextromethorphan polistirex ingestion 90 min prior. On arrival, he was unresponsive, tachycardic, and hypertensive with mydriasis, roving eye movements, rotary nystagmus, and opisthotonos. Approximately 90 min after arrival, he required intubation for airway protection. The blood dextromethorphan concentration from 75 min after arrival was 110 ng/mL (10-40 ng/ml therapeutic). He was extubated approximately 13 h after arrival and discharged that day. Most pediatric dextromethorphan overdoses produce mild symptoms that are not considered to be life-threatening. Life threatening overdoses are rare. The toxic dextromethorphan dose and blood concentration as well as the toxicokinetics of the polistirex formulation are not well defined. Our case suggests that a blood dextromethorphan concentration exceeding 100 ng/mL can be toxic in this age group, however further study is needed.

Chiral analysis of dextromethorphan and levomethorphan in human hair by liquid chromatography-tandem mass spectrometry

PURPOSE

Methorphan exists in two enantiomeric forms including dextromethorphan and levomethorphan. Dextromethorphan is an over-the-counter antitussive drug, whereas levomethorphan is strictly controlled as a narcotic drug. Chiral analysis of methorphan could, therefore, assist clinicians and forensic experts in differentiating between illicit and therapeutic use and in tracing the source of the drug.

METHODS

A method for enantiomeric separation and quantification of levomethorphan and dextromethorphan in human hair was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Hair was extracted in hydrochloric acid/methanol (1:20, v/v). The supernatant were separated using a Supelco Astec Chirobiotic™ V2 column (250 × 2.1 mm, i.d., 5 μm particle size) and analyzed on a triple quadrupole linear ion trap mass spectrometer in multiple reaction monitoring mode.

RESULTS

The limits of detection for dextromethorphan and levomethorphan were 2 and 1 pg/mg, respectively; the lower limit of quantification was 2 pg/mg for both drugs. Good linearity (r > 0.995) was observed for both analytes over the linear range. Precision values were below 10% for both analytes; accuracy values ranged from 87.5 to 101%. The extraction recoveries were 78.3-98.4%, and matrix effects were 70.5-88.6%. This method was applied to human hair samples from 120 people suspected of methorphan use to further distinguish the drug chirality. Dextromethorphan was detected in all 120 samples at a concentration range of 2.7-19,100 pg/mg, whereas levomethorphan was not detected in any sample.

CONCLUSIONS

A sensitive quantitative method was established for the enantiomeric separation of dextromethorphan and levomethorphan in hair. This is the first study to achieve chiral analysis of methorphan in human hair.

US emergency department visits for acute harms from over-the-counter cough and cold medications, 2017-2019

BACKGROUND AND PURPOSE

Characterization of emergency department (ED) visits for acute harms related to use of over-the-counter cough and cold medications (CCMs) by patient demographics, intent of CCM use, concurrent substance use, and clinical manifestations can help guide prevention of medication harms.

METHODS

Public health surveillance data from the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project were used to estimate numbers and population rates of ED visits from 2017 to 2019.

RESULTS

Based on 1396 surveillance cases, there were an estimated 26 735 (95% CI, 21 679-31 791) US ED visits for CCM-related harms annually, accounting for 1.3% (95% CI, 1.2-1.5%) of all ED visits for medication adverse events. Three fifths (61.4%, 95% CI, 55.6-67.2%) of these visits were attributed to non-therapeutic CCM use (nonmedical use, self-harm, unsupervised pediatric exposures). Most visits by children aged <4 years (74.0%, 95% CI, 59.7-88.3%) were for unsupervised CCM exposures. Proportion hospitalized was higher for visits for self-harm (76.5%, 95% CI, 68.9-84.2%) than for visits for nonmedical use (30.3%, 95% CI, 21.1-39.6%) and therapeutic use (8.8%, 95% CI, 5.9-11.8%). Overall, estimated population rates of ED visits for CCM-related harms were higher for patients aged 12-34 years (16.5 per 100 000, 95% CI, 13.0-20.0) compared with patients aged <12 years (5.1 per 100 000, 95% CI, 3.6-6.5) and ≥ 35 years (4.3 per 100 000, 95% CI, 3.4-5.1). Concurrent use of other medications, illicit drugs, or alcohol was frequent in ED visits for nonmedical use (61.3%) and self-harm (75.9%).

CONCLUSIONS

Continued national surveillance of CCM-related harms can assess progress toward safer use.

Psychotic Disorder due to the Use of Marijuana, Dextromethorphan, and Caffeine: A Case Report and Review of the Literature

BACKGROUND: Drug abuse occurs widely in various parts of the world. The drugs that are misused are not only cocaine, or heroin, but also drugs that are commonly prescribed. If you want to get drunk, usually use dextromethorphan (DMP) pills, but now switch to mixing herbal cough medicines with energy drinks. Herbal cough medicine is usually used as a cough reliever, but in teens today, herbal cough medicine is starting to be abused. Mixing energy drinks using herbal cough medicine are motivated by a lack of positive activities or activities, influenced by peers or the environment where the subject lives, lack of application of religious and school education, lack of the role of parents in supervising their children, easy access to herbal cough medicines and drinks energy in large quantities, and the price is cheap. The crime that occurred is not only limited to theft but also drugs and drinking. The only difference, they are not drunk with liquor, but mixed energy drinks with some herbal cough medicine sachets. CASE REPORT: We found a case of acute psychotic disorders due to cannabis use and other psychoactive substances, namely, a mixture of herbal cough medicine containing DMP and energy drinks containing caffeine, after 2 days of use, in a 20-year-old male, found a delusion and hallucinations. CONCLUSIONS: Every use of addictive substances and psychotropic substances will have an impact on life and health. The use of addictive and psychotropic substances when consumed in excess of the dose will damage some organ functions, affect the smooth operation of organ systems, and can also cause acute psychosis.

Alterations in the biochemical indices in Wistar rats exposed to an overdose of codeine and dextromethorphan

OBJECTIVE

This study investigates the impact of repeated oral exposure to two cough syrups containing codeine and dextromethorphan (DXM) on male Wistar rats.

METHODS

We divided 35 rats into seven groups of five rats each. Group A was given 0.5 mL of distilled water, Groups B, C, and D were given 0.1, 0.2 and 0.4 mL/kg body weight (b. w) of cough syrup containing codeine (CSC), respectively, and Groups E, F, and G were administered 0.1, 0.2 and 0.4 mL/kg b. w of cough syrup containing DXM, respectively. The treatment was continued for 28 days. The rats were euthanised under mild diethyl ether anaesthesia. The kidney, liver, and blood of the rats were examined for further analyses.

RESULTS

Significant (p < 0.05) alterations were observed in the liver function tests: ALT, AST, ALP, albumin, and total bilirubin. All doses of CSC and DXM significantly increased the ALT levels (p < 0.05). Furthermore, similar significant alterations were observed for the kidney function parameters such as creatinine, urea, and uric acid (p < 0.05). All doses of DXM caused significant elevations in the levels of urea (p < 0.05). The histopathological evaluations also showed slight changes in the architecture of the liver, kidney, and brain tissues.

CONCLUSION

The findings of this study suggest that overdose of these cough syrups may predispose the consumer to hepatic and renal injuries.

Detection of trace drugs of abuse in baby formula using solid-phase microextraction direct analysis in real-time mass spectrometry (SPME-DART-MS)

The intentional or unintentional adulteration of baby formula with drugs of abuse is one of the many increasingly complex samples forensic chemists may have to analyze. This sample type presents a challenge because of a complex matrix that can mask the detection of trace drug residues. To enable screening of baby formula for trace levels of drugs, the use of solid-phase microextraction (SPME) coupled with direct analysis in real-time mass spectrometry (DART-MS) was investigated. A suite of five drugs was used as adulterants and spiked into baby formula. Samples were then extracted using SPME fibers which were analyzed by DART-MS. Development of a proof-of-concept method was completed by investigating the effects of the DART gas stream temperature and the linear speed of the sample holder. Optimal values of 350°C and 0.2 mm/s were found. Once the method was established, representative responses and sensitivities for the five drugs were measured and found to be in the range of single ng/mL to hundreds ng/mL. Additional studies found that the presence of the baby formula matrix increased analyte signal (relative to methanolic solutions) by greater than 200%. Comparison of the SPME-DART-MS method to a traditional DART-MS method for trace drug detection found at least a factor of 13 improvement in signal for the drugs investigated. This work demonstrates that SPME-DART-MS is a viable technique for the screening of complex matrices, such as baby formula, for trace drug residues and that development of a comprehensive method is warranted.

Cough Remedies for Children and Adolescents: Current and Future Perspectives

Cough is a widespread symptom in children and adolescents. Despite advances in scientific knowledge about the neurophysiological mechanisms underlying the cough reflex, the best therapeutic approaches for children and adolescents who cough remain unclear, and many needs are still unmet. Many remedies for cough are self-prescribed, reflecting strong demand, but significant evidence of their efficacy and safety is missing in pediatric populations. Moreover, as most coughs are part of self-limited illnesses, treatment could be considered unnecessary in some patients. Drug therapy to relieve cough and other symptoms is an essential part of treating a child with cough. However, unfortunately, the number of studies in each category of cough medications is minimal, and dosing and treatment duration varies significantly among studies. Some treatments have been shown to be no more effective than placebo. Lack of clear indications for dosing and treatment duration, the number of available drugs, the numerous active ingredients in products, and multiple caregivers administering medication to children have been considered contributors to an increased risk of inappropriate prescribing, accidental overdosing, and adverse events. This review presents the most recent evidence on the safety and efficacy of available cough remedies, focusing on the pediatric age group, and includes H₁ receptor antagonists, mucolytics and expectorants, drugs acting peripherally on the cough reflex, drugs acting centrally on the cough reflex, drugs acting both peripherally and centrally on the cough reflex, and other compounds, including menthol, glycerol, honey, and medical devices composed of complex natural substances. Future perspectives on new therapeutic targets are also discussed.

Effect of dextromethorphan/quinidine on pentylenetetrazole- induced clonic and tonic seizure thresholds in mice

INTRODUCTION

This study aimed to investigate the effects of dextromethorphan (DM) or dextromethorphan/quinidine (DM/Q) against pentylenetetrazole (PTZ)- induced seizure threshold in mice and the probable involvement of N-methyl d-aspartate (NMDA), sigma-1 and serotonin 1A (5-HT_1A) receptors.

MATERIAL AND METHODS

NMRI male mice (25-30 g) received quinidine (10, 20, and 30 mg/kg), DM (5, 10, 25, and 50 mg/kg) or DM/Q (10/20, 25/20, and 50/20 mg/kg), 30 min before the infusion of PTZ. ketamine (1 and 5 mg/kg), BD-1047 (2.5 and 5 mg/kg) or WAY-100635 (0.5 and 1 mg/kg) were administrated as pre-treatment 30 min before the selected dose of DM/Q. Seizures were induced by intravenous PTZ infusion. All data were presented as means ± S.E.M. One-way ANOVA test was used to determine statistical significance (p < 0.05).

RESULTS

DM (25 and 50 mg/kg) significantly increased PTZ- induced seizure threshold. DM/Q at doses of 10/20 and 25/20 mg/kg had anticonvulsant effect, while at a dose of 50/20 mg/kg attenuated anticonvulsant effect of DM 50 mg/kg. Ketamine (5 mg/kg) or WAY-100635 (1 mg/kg) potentiated, while BD-1047 (2.5 and 5 mg/kg) attenuated the anticonvulsant effect of DM/Q 10/20 mg/kg.

CONCLUSION

The results of present study demonstrate that combination with quinidine potentiates the anticonvulsant effect of DM at lower doses, while attenuates it at higher dose. Meanwhile, the effects of DM/Q on seizure activity likely involve an interaction with NMDA, the sigma-1 or the 5-HT_1A receptor which may be secondary to the elevation of DM levels.

Poison-related visits in a pediatric emergency department: A retrospective analysis of patients who bypass poison control centers

INTRODUCTION

Poison control centers (PCC) are an effective means to prevent unnecessary emergency department (ED) visits associated with poisoning exposures. However, not all patients with poison exposures utilize the PCC. The purpose of this study was to identify unintentional pediatric poisoning exposures presenting to a large US children's hospital that could have been managed onsite (i.e., at home) if consultation with a PCC had occurred prior to the ED visit.

METHODS

Using ED encounters from a tertiary children's hospital, unintentional pharmaceutical, chemical, or fume exposures occurring between October 1, 2014 and September 30, 2015 were identified from ICD-9-CM billing codes. Two specialists in poison information reviewed the medical records of the identified patients who had no contact with the PCC and determined whether these encounters were preventable through PCC triage. Descriptive statistics examined the differences between the encounters. Data were analyzed in R v3.2.4 (Vienna, Austria) and SAS v9.4 (SAS Institute, Cary, NC).

RESULTS

In the total study population (n = 231), 98 (42.4%) were PCC triaged and 133 (57.6%) were caregiver self-referred to the ED. For those who self-referred, 62 (46.6%) patients would have been recommended to be managed onsite instead of presenting at the ED for medical care. Analgesics and household cleaning products were the most common pharmaceutical and chemical exposures, respectively.

CONCLUSIONS

Nearly half of ED visits for pediatric patients with unintentional poisoning exposures could have been avoided by contacting a PCC. Educational and self-efficacy-based interventions are needed to expand the public's use of PCC services.

Treatment of an HIV-affected adolescent with heroin dependence in a low-income country: A clinical case study from Zambia

INTRODUCTION

Although the World Health Organization (WHO) has recommended guidelines for the treatment of opioid dependence, there are myriad challenges to successfully implementing such guidelines in resource constrained settings, such as in low and middle-income countries (LMICs). To highlight these challenges, this paper presents a clinical case study of an adolescent study participant in a randomized controlled trial comparing two counseling programs in Lusaka, Zambia.

CASE DESCRIPTION

This 15 year-old male reported smoking marijuana and heroin daily, and injecting heroin monthly (while needle sharing). The patient was linked to the only physician capable of treating heroin addiction in Zambia. The patient was placed on a 30-day detox regimen of Tramadol administered from home, as in-patient detox services are unavailable in Zambia. The patient experienced complications with out-patient detox, including a relapse that led to violent behavior and temporary incarceration. The patient's treatment regimen was altered to include Lorazepam, a mild sedative, and psychosocial counseling. After completing detox the client was prescribed Naltrexone for maintenance as Methadone is listed as a banned substance in Zambia, and Buprenorphine is not available and is cost prohibitive.

CONCLUSIONS

Despite a considerable amount of time and resources expended to successfully treat the patient, the majority of WHO guidelines for opioid dependence treatment were not attainable within the Zambian context. Additional research into the effectiveness and implementation of evidence-based interventions for substance use in LMICs is warranted.

When good times go bad: managing 'legal high' complications in the emergency department

Patients can use numerous drugs that exist outside of existing regulatory statutes in order to get “legal highs.” Legal psychoactive substances represent a challenge to the emergency medicine physician due to the sheer number of available agents, their multiple toxidromes and presentations, their escaping traditional methods of analysis, and the reluctance of patients to divulge their use of these agents. This paper endeavors to cover a wide variety of “legal highs,” or uncontrolled psychoactive substances that may have abuse potential and may result in serious toxicity. These agents include not only some novel psychoactive substances aka “designer drugs,” but also a wide variety of over-the-counter medications, herbal supplements, and even a household culinary spice. The care of patients in the emergency department who have used “legal high” substances is challenging. Patients may misunderstand the substance they have been exposed to, there are rarely any readily available laboratory confirmatory tests for these substances, and the exact substances being abused may change on a near-daily basis. This review will attempt to group legal agents into expected toxidromes and discuss associated common clinical manifestations and management. A focus on aggressive symptom-based supportive care as well as management of end-organ dysfunction is the mainstay of treatment for these patients in the emergency department.

Assessment and Management of Toxidromes in the Critical Care Unit

The most important diagnostic factor in uncovering a toxic etiology for delirium or critical illness is the clinician's openness to the possibility of its existence. Therefore, a consulting psychiatrist, already prepared to perform the detail-oriented work of sorting out behavioral manifestations of disease, can be a vital asset at the bedside if also attuned to the role of purposeful, accidental, and iatrogenic exposures in the intensive care unit. This article summarizes the presentation, evaluation, and treatment of toxidromes relevant to the work of acute psychosomatic medicine.

In Vitro Study of Adsorption Kinetics of Dextromethorphan Syrup onto Activated Charcoal in Simulated Gastric and Intestinal Fluids

Adsorption kinetics of dextromethorphan (DXM) syrup in simulated gastric and intestinal fluids onto activated charcoal (AC) were investigated in an in vitro model. The adsorption studies were performed as a function of time, initial concentration, and temperature. The quantification of DXM adsorbed onto AC was obtained from the Langmuir adsorption isotherms using HPLC. The maximum adsorption capacities (at 95% confidence limits) of AC for DXM were 111.615 [106.38; 126.85] mg in simulated intestinal environment (pH 6.8) and 78.314 [86.206; 70.422] mg in simulated gastric environment (pH 1.2). The adsorption capacity of AC for DXM in simulated gastric fluid (pH 1.2) was not significantly different from the adoption capacity of AC for DXM in simulated intestinal fluid (pH 6.8). Moreover, the adsorption kinetics behavior of dextromethorphan onto AC followed pseudo-second-order kinetics. Our results show that AC in therapeutically acceptable doses can be beneficial in the majority of oral overdose of DXM.

webPOISONCONTROL: can poison control be automated?

BACKGROUND

A free webPOISONCONTROL app allows the public to determine the appropriate triage of poison ingestions without calling poison control. If accepted and safe, this alternative expands access to reliable poison control services to those who prefer the Internet over the telephone. This study assesses feasibility, safety, and user-acceptance of automated online triage of asymptomatic, nonsuicidal poison ingestion cases.

METHODS

The user provides substance name, amount, age, and weight in an automated online tool or downloadable app, and is given a specific triage recommendation to stay home, go to the emergency department, or call poison control for further guidance. Safety was determined by assessing outcomes of consecutive home-triaged cases with follow-up and by confirming the correct application of algorithms. Case completion times and user perceptions of speed and ease of use were measures of user-acceptance.

RESULTS

Of 9256 cases, 73.3% were triaged to home, 2.1% to an emergency department, and 24.5% directed to call poison control. Children younger than 6 years were involved in 75.2% of cases. Automated follow-up was done in 31.2% of home-triaged cases; 82.3% of these had no effect. No major or fatal outcomes were reported. More than 91% of survey respondents found the tool quick and easy to use. Median case completion time was 4.1 minutes.

CONCLUSION

webPOISONCONTROL augments traditional poison control services by providing automated, accurate online access to case-specific triage and first aid guidance for poison ingestions. It is safe, quick, and easy to use.

Dextromethorphan: An update on its utility for neurological and neuropsychiatric disorders

Dextromethorphan (DM) is a commonly used antitussive and is currently the only FDA-approved pharmaceutical treatment for pseudobulbar affect. Its safety profile and diverse pharmacologic actions in the central nervous system have stimulated new interest for repurposing it. Numerous preclinical investigations and many open-label or blinded clinical studies have demonstrated its beneficial effects across a variety of neurological and psychiatric disorders. However, the optimal dose and safety of chronic dosing are not fully known. This review summarizes the preclinical and clinical effects of DM and its putative mechanisms of action, focusing on depression, stroke, traumatic brain injury, seizure, pain, methotrexate neurotoxicity, Parkinson's disease and autism. Moreover, we offer suggestions for future research with DM to advance the treatment for these and other neurological and psychiatric disorders.

Novel psychoactive substances of interest for psychiatry

Novel psychoactive substances include synthetic cannabinoids, cathinone derivatives, psychedelic phenethylamines, novel stimulants, synthetic opioids, tryptamine derivatives, phencyclidine-like dissociatives, piperazines, GABA-A/B receptor agonists, a range of prescribed medications, psychoactive plants/herbs, and a large series of performance and image enhancing drugs. Users are typically attracted by these substances due to their intense psychoactive effects and likely lack of detection in routine drug screenings. This paper aims at providing psychiatrists with updated knowledge of the clinical pharmacology and psychopathological consequences of the use of these substances. Indeed, these drugs act on a range of neurotransmitter pathways/receptors whose imbalance has been associated with psychopathological conditions, including dopamine, cannabinoid CB1, GABA-A/B, 5-HT2A, glutamate, and k opioid receptors. An overall approach in terms of clinical management is briefly discussed.

Efficacy of flow restrictors in limiting access of liquid medications by young children

OBJECTIVE

To assess whether adding flow restrictors (FRs) to liquid medicine bottles can provide additional protection against unsupervised medication ingestions by young children, even when the child-resistant closure is not fully secured.

STUDY DESIGN

In April and May 2012, we conducted a block randomized trial with a convenience sample of 110 3- and 4-year-old children from 5 local preschools. Participants attempted to remove test liquid from an uncapped bottle with an FR and a control bottle without an FR (with either no cap or an incompletely closed cap).

RESULTS

All but 1 (96%; 25 of 26) of the open control bottles and 82% (68 of 83) of the incompletely closed control bottles were emptied within 2 minutes. Only 6% (7 of 110) of the bottles with FRs were emptied during the 10-minute testing period, none before 6 minutes. Overall, children removed less liquid from the bottles with FRs than from the open or incompletely closed control bottles without FRs (both P < .001). All children assigned open control bottles and 90% of those assigned incompletely closed control bottles removed ≥ 25 mL of liquid. In contrast, 11% of children removed ≥ 25 mL of liquid from uncapped bottles with FRs. Older children (aged 54-59 months) were more successful than younger children at removing ≥ 25 mL of liquid (P = .002) from bottles with FRs.

CONCLUSION

Our findings suggest that adding FRs to liquid medicine bottles limits the accessibility of their contents to young children and could complement the safety provided by current child-resistant packaging.

Dextromethorphan Abuse: A Literature Review

Objective:

To review dextromethorphan abuse patterns from 2002–2012 and emphasize the pharmacist's role in prevention, education, and sales surveillance.

Data Sources:

A literature search was conducted through PubMed (2002-November 2012), EMBASE (2002-November 2012), and International Pharmaceutical Abstracts (2002-November 2012), using the search term dextromethorphan abuse. The Drug Enforcement Administration and National Association of Boards of Pharmacy websites were searched for dextromethorphan abuse and legislative updates. The search was limited to a 10-year period to identify the most current case reports and studies.

Study Selection and Data Extraction:

The limits used were studies/case reports evaluating humans and published in the English language. Only studies and case reports that assessed dextromethorphan abuse were included in the review. Eight studies and 9 case reports met the inclusion criteria.

Data Synthesis:

Case reports and studies demonstrate that there are patterns associated with dextromethor phan abuse. A study using data reported to the National Poison Data System identified Coricidin as the most (65.5%) commonly abused dextromethorphan product until 2006; its abuse has decreased since that time (p < 0.0001). The most common abuse effects and toxicities cited in studies and case reports include agitation, confusion, central nervous system depression, tachycardia, hypertension, lethargy, psychosis, hallucinations, mydriasis, dizziness, and cardiotoxicity. One study identified that 96% of samples tested positive for other substances in addition to dextromethorphan. Coingestion of other substances is also common among dextromethorphan abusers.

Conclusions:

Case reports and studies demonstrate that there are patterns associated with dextromethorphan abuse. It is difficult to identify dextromethorphan as the causative agent of abuse effects because of coingestion of other substances. Studies should examine the pharmacist's role and the association between dextromethorphan sales restrictions and abuse patterns.

"How high do they look?": identification and treatment of common ingestions in adolescents

Adolescents have access to a variety of legal or illicit substances that they use to alter their mood or "get high." The purpose of this review is to provide an overview of common substances adolescents use to get high, including the illicit substances synthetic marijuana or "Spice," salvia, MDMA, synthetic cathinones, and 2C-E. Dextromethorphan and energy drinks are easily accessible substances that teenagers abuse. The toxic effects of common ingestions and treatment of overdose is discussed to inform pediatric providers who provide care for adolescents.

Toxicology in the ICU: Part 2: specific toxins

This is the second of a three-part series that reviews the generalized care of poisoned patients in the ICU. This article focuses on specific agents grouped into categories, including analgesics, anticoagulants, cardiovascular drugs, dissociative agents, carbon monoxide, cyanide, methemoglobinemia, cholinergic agents, psychoactive medications, sedative-hypnotics, amphetamine-like drugs, toxic alcohols, and withdrawal states. The first article discussed the general approach to the toxicology patient, including laboratory testing; the third article will cover natural toxins.

Dextromethorphan abuse in Texas, 2000-2009

Dextromethorphan abuse is increasing in United States. Intentional misuse or abuse ingestions of dextromethorphan-containing products reported to Texas poison centers during 2000-2009 were identified and the distribution of ingestions by selected factors was determined. There were 3,421 total cases; Coricidin® (Schering-Plough Health Care Products, Inc., Memphis, TN) products were involved in 53.6% of cases. The number of cases increased during 2000-2002 and then declined during 2003-2005 before increasing again in 2006 and remaining relatively constant afterward. The majority of patients were male (60.4%) and between 13 and 19 years of age (69.0%). A potentially serious outcome was assigned in 46.2% of the cases and 83.1% were managed at a health care facility.

Chiral analyses of dextromethorphan/levomethorphan and their metabolites in rat and human samples using LC-MS/MS

In order to develop an analytical method for the discrimination of dextromethorphan (an antitussive medicine) from its enantiomer, levomethorphan (a narcotic) in biological samples, chiral analyses of these drugs and their O-demethyl and/or N-demethyl metabolites in rat plasma, urine, and hair were carried out using LC-MS/MS. After the i.p. administration of dextromethorphan or levomethorphan to pigmented hairy male DA rats (5 mg/kg/day, 10 days), the parent compounds and their three metabolites in plasma, urine and hair were determined using LC-MS/MS. Complete chiral separation was achieved in 12 min on a Chiral CD-Ph column in 0.1% formic acid-acetonitrile by a linear gradient program. Most of the metabolites were detected as being the corresponding O-demethyl and N, O-didemethyl metabolites in the rat plasma and urine after the hydrolysis of O-glucuronides, although obvious differences in the amounts of these metabolites were found between the dextro and levo forms. No racemation was observed through O- and/or N-demethylation. In the rat hair samples collected 4 weeks after the first administration, those differences were more clearly detected and the concentrations of the parent compounds, their O-demethyl, N-demethyl, and N, O-didemethyl metabolites were 63.4, 2.7, 25.1, and 0.7 ng/mg for the dextro forms and 24.5, 24.6, 2.6, and 0.5 ng/mg for the levo forms, respectively. In order to fully investigate the differences of their metabolic properties between dextromethorphan and levomethorphan, DA rat and human liver microsomes were studied. The results suggested that there might be an enantioselective metabolism of levomethorphan, especially with regard to the O-demethylation, not only in DA rat but human liver microsomes as well. The proposed chiral analyses might be applied to human samples and could be useful for discriminating dextromethorphan use from levomethorphan use in the field of forensic toxicology, although further studies should be carried out using authentic human samples.

Developmental toxicity of dextromethorphan in zebrafish embryos/larvae

Dextromethorphan is widely used in over-the-counter cough and cold medications. Its efficacy and safety for infants and young children remains to be clarified. The present study was designed to use zebrafish as a model to investigate the potential toxicity of dextromethorphan during embryonic and larval development. Three sets of zebrafish embryos/larvae were exposed to dextromethorphan at 24, 48 and 72 h post fertilization (hpf), respectively, during the embryonic/larval development. Compared with the 48 and 72 hpf exposure sets, the embryos/larvae in the 24 hpf exposure set showed much higher mortality rates which increased in a dose-dependent manner. Bradycardia and reduced blood flow were observed for the embryos/larvae treated with increasing concentrations of dextromethorphan. Morphological effects of dextromethorphan exposure, including yolk sac and cardiac edema, craniofacial malformation, lordosis, non-inflated swim bladder and missing gill, were also more frequent and severe among zebrafish embryos/larvae exposed to dextromethorphan at 24 hpf. Whether the more frequent and severe developmental toxicity of dextromethorphan observed among the embryos/larvae in the 24 hpf exposure set, as compared with the 48 and 72 hpf exposure sets, is due to the developmental expression of the phase I and phase II enzymes involved in the metabolism of dextromethorphan remains to be clarified. A reverse transcription-polymerase chain reaction analysis, nevertheless, revealed developmental stage-dependent expression of mRNAs encoding SULT3 ST1 and SULT3 ST3, two enzymes previously shown to be capable of sulfating dextrorphan, an active metabolite of dextromethorphan.

Combined dextromethorphan and chlorpheniramine intoxication in impaired drivers

Dextromethorphan is a nonprescription antitussive which has been gaining in popularity as an abused drug, because of the hallucinogenic, dissociative, and intoxicating effects it produces at high doses. This report describes a series of eight drivers arrested for driving under the influence of the combined effects of dextromethorphan and chlorpheniramine, and a further four drivers under the influence of dextromethorphan alone. In the combined dextromethorphan/chlorpheniramine cases, blood dextromethorphan concentrations ranged from 150 to 1220 ng/mL (n = 8; mean 676 ng/mL, median 670 ng/mL), and chlorpheniramine concentrations ranged from 70 to 270 ng/mL (n = 8; mean 200 ng/mL, median 180 ng/mL). The four cases without chlorpheniramine present had blood dextromethorphan concentrations between 190 and 1000 ng/mL (mean 570 ng/mL, median 545 ng/mL). Some drivers had therapeutic concentrations of other drugs present. Drivers generally displayed symptoms of central nervous system (CNS) depressant intoxication, and there was gross evidence of impairment in their driving, including weaving, leaving the lane of travel, failing to obey traffic signals, and involvement in collisions. Drug Recognition Expert opinions confirmed that the subjects were under the influence of a drug in the CNS-depressant category.

Dextromethorphan abuse: clinical effects and management

OBJECTIVE

To describe the epidemiology, patient presentation, and clinical management associated with dextromethorphan (DM) abuse.

DATA SOURCES

PubMed/Medline search using terms dextromethorphan and abuse through July 2008, bibliographies of selected publications, epidemiology tracking databases.

STUDY SELECTION

By the authors.

DATA EXTRACTION

English language-published review articles, clinical trials, and case reports that described the epidemiologic and toxicologic profile of DM were included.

DATA SYNTHESIS

DM is a relatively inexpensive and easily accessible over-the-counter (OTC) medication intended for use as an antitussive. Increasingly, illicit use of the drug has been reported. At clinical doses, the drug produces few adverse effects. However, when abused in large quantities (>2 mg/kg), the drug has been associated with a dissociative effect similar to those described by ketamine and phencyclidine abusers. Massive ingestions of the drug may be associated with untoward effects, including tachycardia, hypertension, and respiratory depression. Overdose symptoms may also be associated with coformulated products such as antihistamines and sympathomimetic amines. Management is primarily supportive. Naloxone has been used to manage DM toxicity but with conflicting reports of effectiveness.

CONCLUSION

Recent reports indicate that DM is often abused by individuals seeking its dissociative effects. Clinicians should be aware of the abuse potential of DM. Pharmacists might be particularly cognizant of the risks involved with DM abuse as they control OTC access to the drug.

Endogenous opiates and behavior: 2007

This paper is the thirtieth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2007 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.