Adolescent dimenhydrinate abuse: resurgence of an old problem

Preventing the Abuse and Misuse of Over-the-Counter Medicines: A Survey of Community Pharmacists in Finland

BACKGROUND

Over-the-counter (OTC) medicines intended for short-term use for self-care may be abused or misused.

AIM

To explore the experiences and perceptions of community pharmacists (dispensers, pharmacists, and pharmacy owners) of the use, abuse, and misuse of OTC medicines by pharmacy customers, and to identify their perceptions of the most appropriate methods to prevent inappropriate use of OTC medicines.

METHOD

A cross-sectional national online survey to community pharmacists in Finland. A previously validated structured questionnaire was modified. Three national pharmaceutical associations were contacted to help in recruitment of their members (n = 5594, calculated target sample size n = 360). Descriptive statistical analyses were conducted.

RESULTS

In total, 442 responses were received. Most respondents strongly agreed (Md all = 5) that OTC medicines could be abused or misused; pharmacy owners were more likely to strongly agree than pharmacists (p = 0.012). Pharmacy owners were more likely to think that laxatives were liable for abuse than dispensers (p = 0.008), and that travel sickness medicines were liable for misuse than dispensers (p < 0.001) and pharmacists (p = 0.013). Patient counseling was the most commonly employed method to prevent the problem. Respondents perceived that providing training to staff about OTC medicines that can be abused (Md all = 5) was the most appropriate strategy to prevent OTC medicine abuse; pharmacy owners were more likely to strongly agree or agree of this (p = 0.005) than dispensers. Conclusion: Community pharmacists are aware of the liability of OTC medicines for the potential abuse and misuse. They employ various methods as advising and counseling the customer to support the rational use of OTC medicines.

Misuse and dependence of dimenhydrinate: A mixed studies systematic review

BACKGROUND

Dimenhydrinate (DMH) is an antihistamine used to treat nausea and vomiting. Although widely available in pharmacies as an over the counter medication, there have been reports of potential DMH tolerance and dependence and a possible euphoric potential accompanying heavy use (>100 mg/day). Despite the potential for misuse, there is a gap in the literature concerning patterns, characteristics, and potential mechanisms of DMH misuse.

AIMS

This review aimed to synthesize evidence on the pharmacology, clinical effects, and management of DMH misuse and dependence to inform clinical decision making and relevant drug policy.

METHODS

We conducted a systematic review in accordance with the PRISMA guidelines and using Cochrane collaboration methods. We searched seven databases from their inception through July 2019. To be included in the review, studies needed to measure or focus on one or more dimensions of morbidity or mortality related to the misuse of DMH. Quantitative, qualitative and mixed-method studies were included in order to capture the breadth of possible studies. Studies were excluded if they did not fit into the conceptual framework of the study of if they focused primarily on the misuse of other substances. A narrative synthesis of study findings was pursued given the limited capacity for a quantitative meta-analysis.

FINDINGS

We identified 24 studies, which described a range of neuropsychiatric sequelae related to DMH consumption, including seizures, psychosis, depression, intoxication (resembling anticholinergic syndrome) and withdrawal. The sedative and euphoric properties, readily available nature, and low cost of DMH appear to facilitate DMH dependence, which were more commonly reported among individuals who had concurrent psychiatric disorders, displaying symptoms such as low motivation, poor concentration, and delirium. The overall quality of studies identified by this review was low-largely because the majority of studies were case reports or review articles, with few intervention or cohort studies.

CONCLUSIONS

There is some evidence to suggest the existence of DMH-related syndromes involving intoxication, withdrawal, and dependence, more commonly among long-term, heavy DMH consumers. However, higher quality studies are needed to confirm preliminary findings that there may be a biological basis for such syndromes.

Increased rates of diphenhydramine overdose, abuse, and misuse in the United States, 2005-2016

OBJECTIVES

To describe trends in abuse, misuse, and suicide attempts involving diphenhydramine (DPH).

METHODS

We analyzed intentional DPH exposures of individuals ≥10 years old reported to U.S. Poison Control Centers using data from the National Poison Data System, 2005-2016.

RESULTS

There were 158,774 intentional DPH exposures in our dataset. The rate of intentional exposures increased 63% over the 12-year study period for all ages combined. Suicide attempts involving DPH showed a bimodal distribution-increasing 263% among children 10-14 years of age, and 126 and 143% among those 55-64 and ≥65 years of age, respectively. Older adults in both the 55-64 and ≥65-year-old age groups had about a 230% increase in rates of misuse. Major adverse clinical effects increased by 91%. There were 745 total reported deaths with a 3.6% increase across all age groups.

CONCLUSIONS

Intentional DPH exposures among individuals ≥10 years old have been increasing since 2005. Increasing rates of suicide attempts among children ages 10-14 and increasing misuse among individuals ≥65, coupled with a trend toward greater severity of overdoses, highlight the significant public health impact of this commonly available over-the-counter drug.

Focus on Over-the-Counter Drugs' Misuse: A Systematic Review on Antihistamines, Cough Medicines, and Decongestants

Background: Over the past 20 years or so, the drug misuse scenario has seen the emergence of both prescription-only and over-the-counter (OTC) medications being reported as ingested for recreational purposes. OTC drugs such as antihistamines, cough/cold medications, and decongestants are reportedly the most popular in being diverted and misused. Objective: While the current related knowledge is limited, the aim here was to examine the published clinical data on OTC misuse, focusing on antihistamines (e.g., diphenhydramine, promethazine, chlorpheniramine, and dimenhydrinate), dextromethorphan (DXM)- and codeine-based cough medicines, and the nasal decongestant pseudoephedrine. Methods: A systematic literature review was carried out with the help of Scopus, Web of Science databases, and the related gray literature. For data gathering purposes, both the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and PROSPERO guidelines were followed (PROSPERO identification code CRD42020209261). Results: After completion of the selection, eligibility, and screening phases, some 92 articles were here taken into consideration; case reports, surveys, and retrospective case series analyses were included. Findings were organized according to the specific OTC recorded. Most articles focused here on DXM (n = 54) and diphenhydramine (n = 12). When specified, dosages, route(s) of administration, toxicity symptoms (including both physical and psychiatric ones), and outcomes were here reported. Conclusion: Results from the systematic review showed that the OTC misusing issues are both widespread worldwide and popular; vulnerable categories include adolescents and young adults, although real prevalence figures remain unknown, due to a lack of appropriate monitoring systems. Considering the potential, and at times serious, adverse effects associated with OTC misusing issues, healthcare professionals should be vigilant, and ad hoc preventative actions should be designed and implemented.

Updates in the general approach to the pediatric poisoned patient

Poison prevention remains essential to prevent the most vulnerable population from becoming exposed to potentially lethal toxins. The evaluation of a child presumed to have been exposed to a toxic substance should include a precise history of the exposure, a physical examination, and knowledge of current ingestions and recreational practices. New treatments and research guiding therapy continue to evolve. Poison centers and medical toxicologists can be consulted to assist with the diagnosis of medicinal/drug overdoses, for advice about the pitfalls inherent in stabilizing children who have been exposed to toxic compounds, and for treatment recommendations based on the latest research.

Diphenhydramine and dimenhydrinate poisoning: an evidence-based consensus guideline for out-of-hospital management

In 2003, there were 28,092 human exposures to diphenhydramine reported to poison centers in the US. A related drug, dimenhydrinate, is a less frequent cause of poisonings. Between January 2000 and June 2004, there were 2,534 reported dimenhydrinate ingestions in children less than 6 years of age. An evidence-based expert consensus process was used to create this guideline. Relevant articles were abstracted by a trained physician researcher. The first draft was created by the primary author. The entire panel discussed and refined the guideline before distribution to secondary reviewers for comment. The panel then made changes based on the secondary review comments. The objective of this guideline is to assist poison center personnel in the appropriate out-of-hospital triage and initial management of patients with a suspected ingestion of diphenhydramine or dimenhydrinate, or a dermal exposure to diphenhydramine. This guideline is based on an assessment of current scientific and clinical information. The expert consensus panel recognizes that specific patient care decisions may be at variance with this guideline and are the prerogative of the patient and the health professionals providing care, considering all of the circumstances involved. This guideline does not substitute for clinical judgment. The panel's recommendations for dermal or oral exposures to diphenhydramine or oral exposures to dimenhydrinate follow. The grade of recommendation is in parentheses: 1) All patients with suicidal intent, intentional abuse, or in cases in which a malicious intent is suspected (e.g., child abuse or neglect) should be referred to an emergency department (Grade D). 2) In patients without evidence of self-harm, abuse, or malicious intent, poison center personnel should elicit additional information including the time of the ingestion or dermal exposure, determination of the precise dose ingested, and the presence of co-ingestants (Grade D). 3) Patients experiencing any changes in behavior other than mild drowsiness or mild stimulation should be referred to an emergency department. Examples of moderate to severe symptoms that warrant referral include agitation, staring spells, inconsolable crying, hallucinations, abnormal muscle movements, loss of consciousness, seizures, or respiratory depression (Grade D). 4) For patients referred to the emergency department, transportation via ambulance should be considered based on several factors including the condition of the patient and the length of time it will take the patient to arrive at the emergency department (Grade D). 5) If the patient has no symptoms, and more than 4 hours have elapsed between the time of diphenhydramine ingestion and the call to the poison center, referral to an emergency department is not recommended. For dermal exposures to diphenhydramine, if the patient has no symptoms and it has been more than 8 hours since the diphenhydramine was thoroughly removed from the skin, referral to an emergency department is not recommended (Grade D). 6) Patients with acute ingestions of less than a toxic dose of diphenhydramine, or chronic exposures to diphenhydramine and no or mild symptoms, can be observed at home with instructions to call the poison center back if symptoms develop or worsen. The poison center should consider making a follow-up call at approximately 4 hours after ingestion (Grade D). 7) Children less than 6 years of age who ingest at least 7.5 mg/kg of diphenhydramine should be referred to an emergency department (Grade D). 8) Patients 6 years of age and older who ingest at least 7.5 mg/kg or 300 mg of diphenhydramine (whichever is less), should be referred to an emergency department (Grade D). 9) If the patient has no symptoms, and more than 6 hours have elapsed between the time of dimenhydrinate ingestion and the call to the poison center, referral to an emergency department is not recommended (Grade D). 10) Patients with acute ingestions of less than a toxic dose of dimenhydrinate, or chronic exposures to dimenhydrinate and no or mild symptoms, can be observed at home with instructions to call the poison center back if symptoms develop or worsen. The poison center should consider making a follow-up call at approximately 6 hours after ingestion (Grade D). 11) Children less than 6 years of age ingesting at least 7.5 mg/kg of dimenhydrinate should be referred to an emergency department (Grade D). 12) Patients 6 years of age and older ingesting at least 7.5 mg/kg or 300 mg of dimenhydrinate (whichever is less), should be referred to an emergency department for evaluation (Grade D). 13) Following oral exposures of diphenhydramine or dimenhydrinate, do not induce emesis. Because of the potential for diphenhydramine or dimenhydrinate to cause loss of consciousness or seizures, activated charcoal should not be administered en route to an emergency department (Grade D). 14) For chronic dermal exposures of diphenhydramine, skin decontamination (with water or soap and water) should be attempted prior to transporting a patient to an emergency department unless moderate to severe symptoms are already present. In this circumstance, transportation should not be delayed, and EMS personnel should attempt skin decontamination en route to the emergency department (Grade D). 15) Intravenous sodium bicarbonate may be administered by EMS personnel if QRS widening (QRS >0.10 msec) is present and if authorized by EMS medical direction (Grade D). 16) Physostigmine should be reserved for administration in a hospital (Grade D). 17) Benzodiazepines may be administered by EMS personnel if agitation or seizures are present, and if authorized by EMS medical direction (Grade D).

The adolescent and substance use, an approach to office management

Adolescence is a period of transition. During this time young people explore many options in an attempt to define who they are. Substance use or abuse is an area of experimentation that creates anxiety for everyone involved and in which, as a health care provider, a physician may be asked to intervene. This article provides general principles regarding substance use, information about commonly used drugs, and recommendations on the diagnosis and management of this problem in an office setting.

Delirium in the postoperative cardiac patient: a review

BACKGROUND AND AIM OF REVIEW: Cardiac surgery is increasingly common and relatively safe, but there are frequent reports of neuropsychiatric sequelae occurring in the postoperative period. One of the most common neuropsychiatric presentations of cardiac surgery is delirium, also called postcardiotomy delirium (PCD). Despite the vast numbers of cardiac surgeries performed today, there is a paucity of data on risk factors and management options of PCD available to the clinician. This review aims to summarize available information, increase clinicians' awareness of PCD and suggest effective management of this illness.

METHODS

Our literature search was completed using the databases Medline and CINAHL; it was limited to human and English language studies from 1964 to the present. Search terms included "delirium," "agitation," "postoperative," "cardiac," "neuropsychiatric," "neuroleptics," "psychosis," "surgery," "treatment," "postcardiotomy," and "pharmacotherapy."

RESULTS

Our review of the literature revealed several risk factors for PCD, as well as various options for its pharmacological management.

CONCLUSIONS

A multifactorial model should be applied when considering risk stratification for and prevention of delirium postoperatively. Pharmacologically, conventional antipsychotic agents, such as haloperidol, have long been used to manage delirium. In light of haloperidol's side effects, particularly those applicable to the cardiac patient, further research is required into the role of second generation antipsychotics. These agents are common in clinical use, and may be the preferred medications.

High school students' misuse of over-the-counter drugs: a population-based study in an urban county

A survey of high school students (n = 39,345) found 4.7% occasionally misuse over-the-counter drugs (i.e., to get high) and an additional 2.1% reported misuse during the past month. Misuse was more common among older white and Native American youths and was associated with depressive affect and other substance use, especially alcohol and illicit drugs.

Development of a community pharmacy-based model to identify and treat OTC drug abuse/misuse: a pilot study

OBJECTIVE

The aim of this study was to develop and pilot a harm-minimisation model for the identification and treatment of over-the-counter (OTC) drug abuse/misuse by community pharmacists.

METHOD

Extensive consultation was conducted during the development of the model. This included an exploratory conference involving an interdisciplinary group of delegates and detailed individual consultation with a range of healthcare practitioners. Consultation with a psychologist specialising in communication skills allowed development of the communication aspects of the model. A comprehensive manual detailing the model was prepared.

RESULTS

The model is designed to be used by community pharmacists in conjunction with other healthcare professionals. It focuses on the abuse/misuse of opioids, laxatives and antihistamines and can be broadly divided into three phases, namely: patient identification and recruitment, treatment/referrals and data collection/outcome measurement. Client identification is via record-keeping which is implemented alongside an information campaign promoting safe use of OTC medicines. Once identified, the pharmacist aims to recruit clients using the developed communication strategies. Treatment depends on whether the problem is misuse or abuse and on the product. Several treatment paths are available including treatment according to an agreed protocol and referring to the GP or community addiction team (CAT). Two pharmacists were recruited and trained to pilot the model. Of the clients, 18 were identified as abusing/misusing OTC products over a one-month period. The subject of inappropriate OTC use was raised with 14 of these clients. Some success was noted in that clients agreed to stop using the product and/or to try safer alternatives. As expected, some sales had to be refused, as the client was unwilling to accept the pharmacist's intervention.

CONCLUSION

This study represents the first reported structured attempt by community pharmacists in the UK to address the abuse/misuse of OTC medication. Work is now ongoing to modify this model in light of the pilot study findings.

Dimenhydrinate produces a conditioned place preference in rats

Dimenhydrinate (DMH; trade names Gravol and Dramamine) is a compound of diphenhydramine (DP) and 8-chlorotheophylline in equimolar ratios. DMH has been reported to be abused by humans for its euphoric and hallucinogenic properties but few studies have evaluated its reinforcing effects in animals. To evaluate the hypothesis that DMH and its constituents DP and 8-chlorotheophylline are rewarding in animals, rats were tested for conditioned place preference (CPP). The paradigm consisted of pre-exposure (three 15-min sessions of access to both sides of the chamber), conditioning [eight 30-min pairings of one side with drug (four sessions) and, on alternate days, the other side with vehicle (four sessions)] and test phases (three 15-min sessions of access to both sides of the chamber). Significant preferences for the drug-paired location were found on test session one after conditioning with 60.0, but not 25.0, 40.0 or 50.0 mg/kg of DMH, and after conditioning with 37.8 but not 27.0 or 32.4 mg/kg of DP. No preference was found after conditioning with 23.0, 27.6 or 32.2 mg/kg of 8-chlorotheophylline. All three drugs stimulated locomotor activity during conditioning sessions and DMH and DP showed sensitization over conditioning sessions. DMH doses that showed sensitization (25.0 and 40.0 mg/kg) were lower than the dose (60.0 mg/kg) that produced a CPP revealing a dissociation of locomotor stimulating versus rewarding effects. Results reveal that DMH and DP have rewarding properties, although the molar equivalent dose-response curve for DP appeared to be further to the right than that for DMH. Future investigations into the neurotransmitter systems modulating this effect are awaited.

Drug information libraries on the Internet

In the past several years there has been a dramatic proliferation of drug-related sites on the Internet. This article reviews the information found at selected Internet drug information libraries, and comments on its accuracy and implications. Drug-related sites were found by initially performing an Internet search on "psychoactive drugs" and then exploring links among the sites identified. Sites were chosen on the basis of comprehensiveness of information and positive or tolerant attitude toward drug use. While all classes of drugs are discussed at these sites, the primary foci of interest are synthetic and naturally occurring hallucinogens. Many of the biological materials discussed are legal and readily available. Information surveyed at these sites was largely accurate regarding the effects of various substances and biological sources of psychoactive compounds.

CONCLUSIONS

Internet drug information libraries contain large amounts of information about a wide variety of drugs, including previously little-known biological sources of hallucinogens. The availability of this information could have significant effects on patterns of drug use.

Abuse/misuse of non-prescription drugs

AIM

To investigate the abuse of non-prescription (over-the-counter; OTC) products in Northern Ireland.

METHOD

A structured questionnaire covering various aspects of OTC drug abuse was mailed to all 509 community pharmacies in Northern Ireland.

RESULTS

253 responses were received (response rate 49.7%) after two mailings. Pharmacists named 112 OTC products they perceived were being abused in Northern Ireland. These were classified into 8 groups, with opioids, antihistamines and laxatives the most frequently reported. The frequency of abuse of all product groups was perceived to be either increasing or static. The number of clients suspected of abuse over a three-month period ranged from 0 to 700 (median = 10, mode = 6) with 55% being regular customers. Pharmacists employed several methods to limit patient access to products of abuse. The most common technique was to keep the product out of sight. Others included additional client questioning, providing advice and limiting the quantity of product sold. The majority of respondents agreed their role could be extended to include other methods of dealing with abusers, including participation in harm-reduction programmes to wean abusers off products. Geographical region and location of pharmacy were not significant factors in the abuse of OTC products.

CONCLUSIONS

Pharmacists in Northern Ireland perceive abuse and misuse of OTC products to be occurring in practice. Current methods employed for dealing with it are inadequate. Research into methods of effectively dealing with OTC abuse/misuse is required and has commenced on the basis of these findings.