© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
LETTER TO THE EDITOR
Ketamine analogues multiplying in Hong Kong
C Li, MB, BS1,2; CK Lai, MSc2;
Magdalene HY Tang, PhD1,2; Cary CK Chan, MB, BS3; YK
Chong, FHKCPath, FHKAM (Pathology)1,2; Tony WL Mak, FRCPath,
FHKAM (Pathology)1,2
1 Hospital Authority Toxicology
Reference Laboratory, Hong Kong
2 Chemical Pathology Laboratory,
Department of Pathology, Princess Margaret Hospital, Hong Kong
3 Accident and Emergency Department,
Caritas Medical Centre, Hong Kong
Corresponding author: Dr Tony WL Mak (makwl@ha.org.hk)
Full
paper in PDF
To the Editor—New psychoactive substances
are increasingly seen in Hong Kong. We have previously reported an
outbreak affecting 52 patients involving a ketamine analogue, 2-oxo-PCE,
which is much more potent than ketamine and caused more severe clinical
adverse effects.1 2 We report the recent identification of two other
ketamine analogues, 2-fluoro-deschloroketamine
[2-(2-fluorophenyl)-2-methylamino-cyclohexanone] and deschloro-ketamine
(2-phenyl-2-methylamino-cyclohexanone), in urine samples of two unrelated
ketamine abusers.
The 2-fluoro-deschloroketamine was first
synthesised in 2014 as a ketamine derivative.3
To date, there have been no case reports of its abuse or poisoning in the
scientific literature. Deschloroketamine was first described in 1962 and
its recreational use was first reported in 2015.4
Both drugs belong to the arylcyclohexylamine class which is known to
possess antagonist activity at the N-methyl-d-aspartate receptor.5 User reports on internet forums showed that
2-fluoro-deschloroketamine has a similar potency as ketamine, whereas
deschloroketamine is more potent than ketamine. These two drugs are not
detected by common urine toxicology screening methods.
Frontline clinicians should be aware of patients
with suspected ketamine abuse but with negative urine immunoassay and
toxicology results. In point of fact, the kind of new psychoactive
substances greatly outnumbers traditional drugs of abuse nowadays.4 Poisoned patients or drug abusers may present with
unfamiliar clinical toxidromes. Traditional toxicology analyses usually
cannot determine the true nature of such new psychoactive substances.
Analysis of these substances is available in our laboratory and can be
requested by clinicians in Hong Kong.
Author contributions
C Li, MHY Tang, YK Chong, and TWL Mak drafted the
manuscript. All authors contributed substantially to the concept or design
or the study, acquisition of data, analysis or interpretation of the data,
and critical revision of the manuscript for important intellectual
content. All authors had full access to the data, contributed to the
study, approved the final version for publication, and take responsibility
for its accuracy and integrity.
Conflicts of interest
All authors have disclosed no conflicts of
interest.
References
1. Chong YK, Tang MH, Chan CL, Li YK, Ching
CK, Mak TW. 2-oxo-PCE: ketamine analogue on the streets. Hong Kong Med J
2017;23:665-6. Crossref
2. Tang MH, Chong YK, Chan CY, et al.
Cluster of acute poisonings associated with an emerging ketamine analogue,
2-oxo-PCE. Forensic Sci Int 2018;290:238-43. Crossref
3. Moghimi A, Rahmani S, Zare R,
Sadeghzadeh M. Synthesis of 2-(2-fluorophenyl)-2-methylamino-cyclohexanone
as a new ketamine derivative. Synth Commun 2014;44:2021-8. Crossref
4. European Monitoring Centre for Drugs and
Drug Addiction. EMCDDA-Europol 2015 Annual Report on the implementation of
Council Decision 2005/387/JHA. Available from:
http://www.emcdda.europa.eu/publications/implementation-reports/2015_en.
Accessed 12 Mar 2019.
5. Morris H, Wallach J. From PCP to MXE: a
comprehensive review of the non-medical use of dissociative drugs. Drug
Test Anal 2014;6:614-32. Crossref