Letter to the Editor

Sio-pan Chan 陳少斌

Dear Editor,

Thank you for referencing my case report, “Z drug and benzodiazepine abuse and withdrawal – a case report,” in your editorial in the December 2025 issue of The Hong Kong Practitioner.

I am writing to offer a brief clarification on the pharmacological mechanism discussed, which is central to understanding the case. As detailed in my report, while both benzodiazepines and Z drugs act on the GABA-A receptor, their subunit selectivity differs significantly.

Benzodiazepines exert their combined hypnotic, anxiolytic, and muscle relaxant effects through action on both the α1 and α2 subunits. In contrast, Z drugs like zolpidem are highly selective for the α1 subunit, mediating primarily hypnotic effects. Due to their negligible activity at the α2 subunit, they lack meaningful anxiolytic efficacy and are therefore not indicated for anxiety disorders.

This distinction is critical to the case I described, where the patient inappropriately used zolpidem to manage stage fright - an anxiety-related condition - leading to dose escalation and misuse.

I hope this clarification is helpful for your readers in distinguishing between these drug classes. Thank you for your attention to this matter.

Reference

Kathy KL Tsim et al. To live well. Hong Kong Pract 2025;47:90-92.

Sio-pan Chan, MBBS (HK), DFM (HKCU), FHKFP, FHKAM (Family Medicine)
Family Physician in private practice

Authors’ reply

Dear Dr Chan,

Re: Editorial, Vol. 47 No. 4, December 2025

Thank you for the clarification on the pharmacological difference and pathway of action between benzodiazepines and Z drugs. Your case report certainly highlighted an important issue that we as family physicians might come to deal with in our daily practice. Your support and help in enriching not only our knowledge but our daily practice is greatly appreciated.

Yours sincerely,