Diphenhydramine: Time to Move on?

Impact of baseline steroids on the efficacy of neoadjuvant immunochemotherapy in locally advanced esophageal squamous cell carcinoma

BACKGROUND

Immunochemotherapy involving the combination of programmed cell death 1/programmed cell death ligand 1 inhibitors with chemotherapy has advanced the treatment of locally advanced esophageal squamous cell carcinoma (ESCC). The use of corticosteroids as pretreatment might reduce immunotherapy efficacy.

AIM

To investigate the impact of baseline corticosteroid use on neoadjuvant immunochemotherapy (nIC) outcomes in locally advanced ESCC patients.

METHODS

Patients with locally advanced ESCC who received nIC at Sun Yat-sen University Cancer Center and the Third Affiliated Hospital of Sun Yat-sen University were included. Patients were divided into dexamethasone and antihistamine groups on the basis of the administered pretreatment. Antiallergic efficacy and safety were evaluated, as well as its impact on short-term efficacy [complete pathological response (pCR), major pathological response (MPR)] and long-term efficacy [overall survival (OS), progression-free survival (PFS)] of nIC.

RESULTS

From September 2019 to September 2023, 142 patients were analyzed. No severe treatment-related adverse events or deaths were observed. Allergy occurrence was greater in the antihistamine group (P = 0.014). Short-term efficacy was not significantly different: The pCR rates were 29.9% and 40.0%, and the MPR rates were 57.9% and 65.7% in the dexamethasone and antihistamine groups, respectively. The long-term efficacy was not significantly different: The 2 years OS rates were 95.2% and 93.5%, and the 2 years PFS rates were 90.3% and 87.8%. Subgroup analysis revealed no difference in OS between the 20 mg dexamethasone group and the < 20 mg dexamethasone group, but PFS was significantly greater in the 20 mg dexamethasone group (93.9% vs 56.4%, P = 0.001).

CONCLUSION

Dexamethasone or antihistamines can be used before nIC in locally advanced ESCC without affecting short- or long-term efficacy. Administering 20 mg dexamethasone before nIC may improve PFS in ESCC.

Treating Diphenhydramine Overdose: A Literature Review of Currently Available Treatment Methods

From 2019 to 2020, antihistamines were found in 15% of all US drug overdose deaths, often co-administered with fentanyl, with 3.6% of overdose deaths due to antihistamines alone. The most common antihistamine found in all these reported deaths is diphenhydramine, a ubiquitous, over-the-counter and clinically important medication. Currently, there is no antidote for diphenhydramine overdose. This review summarizes the adverse health effects and current emergency medicine treatments for diphenhydramine. Several emergency medicine case reports are reviewed, and the efficacy and outcomes of a variety of treatments are compared. The treatments reviewed include the more traditional antihistamine overdose therapeutics physostigmine and sodium bicarbonate, as well as newer ones such as donepezil, dexmedetomidine, and lipid emulsion therapy. We conclude that more study is needed to determine the ideal therapeutic approach to treating antihistamine overdoses.

Diphenhydramine-involved Fatal and Nonfatal Drug Overdoses in Tennessee, 2019-2022

BACKGROUND

Diphenhydramine (DPH), known as the brand name Benadryl, is an over-the-counter medication associated with accidental ingestion leading to nonfatal overdoses. Additionally, DPH has been used in tandem with illicit substances leading to fatal drug overdoses.

OBJECTIVE

In response to DPH being seized with illicit drugs as an adulterant, as well as its growing intentional misuse, we sought to explore its recent involvement in fatal and nonfatal drug overdoses in the state of Tennessee.

METHODS

We conducted a statewide cross-sectional study to determine the characteristics of DPH-involved fatal and nonfatal overdoses in Tennessee during 2019-2022 using data from the State Unintentional Drug Overdose Reporting System, the Electronic Surveillance System for the Early Notification of Community-based Epidemics, and the National Forensic Laboratory Information System Public Data Query System. Frequencies were generated to compare demographic characteristics, circumstances, and toxicology between fatal and nonfatal DPH-involved overdoses.

RESULTS

We identified 143 suspected nonfatal DPH and 409 fatal DPH-involved overdoses in Tennessee from 2019 to 2022. Nonfatal overdoses remained consistent while fatal overdoses peaked in 2021. Most nonfatal overdoses were under 18 (63.4%), while most fatal overdoses were between 18 and 64 years of age (95.7%). For fatal overdoses, fentanyl was the most prevalent substance on toxicology followed by prescription opioids.

CONCLUSION

Nonfatal overdoses remained consistent while fatal overdoses peaked in 2021 in Tennessee. Use of DPH among other illicit substances lends to evidence suggesting its use as an adulterant. Monitoring of DPH-involved fatal and nonfatal overdoses is critical to inform harm reduction initiatives.

Factors associated with the use of over-the-counter sleep aids containing diphenhydramine: A cross-sectional study in Saudi Arabia

Introduction

Diphenhydramine, either alone or in combination with pain relievers, is one of the widely used over-the-counter sleep aids. However, few studies have evaluated the use of diphenhydramine-containing products, such as Panadol Night, in Saudi Arabia. Therefore, the objectives of this study were to assess the prevalence of Panadol Night use and to identify factors associated with its use in the Eastern Province of Saudi Arabia.

Methods

A cross-sectional study was conducted among adults aged 18 years or older in the Eastern Province of Saudi Arabia. Data were collected through an online self-administered questionnaire from 05 March 2022 to 20 March 2022. Chi-square tests and multivariable logistic regression models were used to examine the associations between Panadol Night use in the past month and independent variables.

Results

A total of 1244 adults participated in the survey. Approximately, 42.3% reported that they have used Panadol Night in their lifetime; 12.1% used Panadol Night in the past month. The majority of the Panadol Night users (62.4%) reported that their use was based on their family/friends' recommendations, while 23.6% used Panadol Night based on healthcare providers' recommendations. The multivariable logistic regression models showed that gender, health related fields, perceived safety and effectiveness of Panadol Night, a history of insomnia, trouble sleeping due to pain, and sleep quality were significantly associated with the use of Panadol Night in the past month.

Conclusions

Our findings indicated that adults' perceptions of the effectiveness and safety of Panadol Night were significantly associated with its use. Also, adults in non-health related fields were more likely to use Panadol Night compared to those in health related fields. This suggests the need for raising awareness about the appropriate use of Panadol Night. Community pharmacists can play an essential role in educating patients during the time of purchase.