Intoxication with over-the-counter antitussive medication containing dihydrocodeine and chlorpheniramine causes generalized convulsion and mixed acidosis

An autopsy case of BRONTM overdose with multiple drug ingestion

A man in his forties was found dead in his friend's home, with moderate putrefaction. Quantitative toxicological analysis showed that concentrations of caffeine, chlorpheniramine, dihydrocodeine, and methylephedrine were 183.3 µg/mL, 0.533 µg/mL, 2.469 µg/mL and 8.336 µg/mL, respectively. Ephedrine, amitriptyline, nortriptyline, etizolam, fluvoxamine and 7-aminoflunitrazepam were detected in an aortic blood sample. Caffeine, chlorpheniramine, dihydrocodeine and methylephedrine are the main components of BRON^TM, an over-the-counter antitussive sold in Japan. Those concentrations in blood were within fatal ranges. Caffeine is classified as a methylxanthine and is mainly metabolized by cytochrome P450 (CYP)1A2. Fluvoxamine is a potent CYP1A2 inhibitor. Blood fluvoxamine concentration was within the therapeutic range, but would have increased blood caffeine level by the inhibition of caffeine metabolism. The conclusion was that his death was caused by BRON^TM overdose. Inhibition of caffeine metabolism may increase blood caffeine concentrations. This suggests that more attention should be paid to potential interactions between multiple drugs.

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.

Drug treatments in patients with cardiac diseases and epilepsy

OBJECTIVE

Comorbidity between epilepsy and heart diseases is frequent.

METHODS

All drugs classified within the group of drugs for cardiovascular system according to the Anatomical Therapeutic Chemical (ATC) classification system were reviewed for their effects on seizures or epilepsy.

RESULTS

Several agents showed antiseizure properties in animal models of seizures and/or in patients with epilepsy and only few were proconvulsant. Drugs with anticonvulsant effects include mecamylamine and guanfacine (antihypertensive drugs), indapamide, amiloride, furosemide and bumetanide (diuretics), fasudil (peripheral vasodilator), bioflavonoids (vasoprotective drug), propranolol (beta blocking agent), isradipine, nimodipine, verapamil and diltiazem (calcium channel blockers: CCBs), fosinopril and zofenopril (agents acting on the renin-angiotensin system), several statins, and fenofibrate (lipid-modifying agents). Drugs with proconvulsant properties in experimental models or in patients include reserpine, buflomedil, naftidrofuryl, and clonidine and propranolol at high doses. Drug-drug interactions (DDI) between antiseizure medications (ASMs) and drugs for cardiovascular system were also searched in two leading publicly accessible drug compendia. The most important DDIs occur between enzyme-inducing (EI) ASMs and ivabradine, ranolazine, macitenan and between EI-ASMs and the CCBs felodipine, nicardipine, nisoldipine, and verapamil. Simvastatin and atorvastatin are the lipid-modifying agents with more DDIs with EI-ASMs. Several pharmacodynamic interactions have been also documented.

DISCUSSION AND CONCLUSIONS

Available data show that the treatment of patients with epilepsy and vascular comorbidities is challenging and requires the appropriate knowledge of pharmacological properties of drugs and drug interactions.

Over-the-counter medicine abuse - a review of the literature

BACKGROUND

The sale of over-the-counter (OTC) medicines from pharmacies can help individuals self-manage symptoms. However, some OTC medicines may be abused, with addiction and harms being increasingly recognised. This review describes the current knowledge and understanding of OTC medicine abuse.

APPROACH

Comprehensive search of international empirical and review literature between 1990 and 2011.

FINDINGS

OTC MEDICINE ABUSE WAS IDENTIFIED IN MANY COUNTRIES AND ALTHOUGH IMPLICATED PRODUCTS VARIED, FIVE KEY GROUPS EMERGED: codeine-based (especially compound analgesic) medicines, cough products (particularly dextromethorphan), sedative antihistamines, decongestants and laxatives. No clear patterns relating to those affected or their experiences were identified and they may represent a hard-to-reach group, which coupled with heterogeneous data, makes estimating the scale of abuse problematic. Associated harms included direct physiological or psychological harm (e.g. opiate addiction), harm from another ingredient (e.g. ibuprofen-related gastric bleeding) and associated social and economic problems. Strategies and interventions included limiting supplies, raising public and professional awareness and using existing services and Internet support groups, although associated evaluations were lacking. Terminological variations were identified.

CONCLUSIONS

OTC medicine abuse is a recognised problem internationally but is currently incompletely understood. Research is needed to quantify scale of abuse, evaluate interventions and capture individual experiences, to inform policy, regulation and interventions.

Restricting cough and cold medicines in children

AIMS

Based on concerns about safety and efficacy, international authorities have either advised against the use of cough and cold medication or considering such action. We aimed to systematically review the evidence for the effectiveness and safety of cough and cold medicines in children.

METHODS

We conducted a systematic review to identify studies relating to the use of products to treat symptoms of the common cold, influenza or allergic rhinitis, and relating to poisoning or toxicity from unintentional ingestion or overdose in children (<12 years). Medline, Embase and the Cochrane database were searched. No meta-analysis was undertaken because of the paucity of evidence, multiple medicines available, and the need to consider both effectiveness and safety.

RESULTS

Seventy two relevant studies or clinical reports were identified. There was little support for the effectiveness of these medicines for acute cough or the common cold in children. However, the majority of these medicines do not appear to be highly toxic in children and are not a major cause of severe effects following unintentional poisoning. The common use of these agents does not appear to be responsible for increased deaths in young children. Many cases of toxicity from cough and cold medications in young children are a result of therapeutic error. Particular medications, including diphenhydramine and codeine, appear to be associated with a high frequency of severe adverse effects and toxicity.

CONCLUSION

Restriction of cough and cold medicines in children is supported by currently available evidence.