Aconite poisoning over 5 years: a case series in Hong Kong and lessons towards herbal safety.
BACKGROUND
Aconite poisoning is a severe, life-threatening poisoning related to the use of traditional Chinese medicine (TCM). Despite current legislation, repeated poisoning cases are steadily encountered.


OBJECTIVE
The aim of the study was to summarize the clinical features and to elucidate the causative and contributory factors leading to aconite poisoning.


METHODS
This study was conducted within the Hospital Authority Toxicology Reference Laboratory, which is the sole tertiary referral clinical toxicology laboratory in Hong Kong. This retrospective study reviewed all confirmed aconite poisoning cases handled by a clinical toxicology laboratory between April 2004 and July 2009. The diagnosis in all cases was confirmed biochemically by detecting aconitum alkaloids in urine specimens. Additionally, herbal specimens were morphologically identified and herbal formulae were studied and transcribed. The cause of poisoning for each case was determined whenever possible.


RESULTS
Fifty-two cases were examined in this aconite poisoning case series. Neurological, cardiovascular and gastrointestinal toxicities were encountered in 49 (94.2%), 46 (88.5%) and 31 (59.6%) patients, respectively. The poisoning was severe in 6 (11.5%) patients, moderate in 17 (32.7%) patients and mild in 29 (55.8%) patients. Amongst 44 patients (84.6%) in whom the underlying reasons of poisoning could be determined, four major causes were found. These included overdose - prescription of a higher than recommended dosage of aconite herbs in 17 (32.7%) cases; 'hidden' poisoning (the aconite herb was not prescribed but dispensed inadvertently) in 17 (32.7%) cases; usage of inadequately processed herbs in 7 (13.5%) cases; and dispensary error in 2 (3.9%) cases. No case fatality was recorded.


CONCLUSIONS
In the majority of cases in this series, the causes of poisoning can be traced to poor-quality herbs, poor quality of prescription practice, or dispensary errors. The quality issues of TCM practice should be critically addressed to minimize this poisoning threat.
Hospital Authority Toxicology Reference Laboratory, Princess Margaret Hospital, Hospital Authority, Hong Kong.
Sammy Pak Lam
SP
Chen
Sau Wah
SW
Ng
Wing Tat
WT
Poon
Chi Kong
CK
Lai
Teresa Man Shan
TM
Ngan
Man Li
ML
Tse
Thomas Yan Keung
TY
Chan
Albert Yan Wo
AY
Chan
Tony Wing Lai
TW
Mak
D031841:Aconitum / Q000506:poisoning*; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000506:poisoning*; D006723:Hong Kong; D006801:Humans; D008508:Medication Errors / Q000706:statistics & numerical data; D008516:Medicine, Chinese Traditional / Q000009:adverse effects*; D012189:Retrospective Studies
D004365:Drugs, Chinese Herbal