Transcript Case 8

Clinical Toxicology Case
Presentation
By Dr. Kevin Go,UCH.
A woman presenting with numbness
and hypotension after taking herbal
medicine.
History
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F/ 44
History of right knee & thigh pain for 2 years
Attended a herbalist on 21/12/2004
Took some herbal broth in the evening
Develop perioral numbness, abdominal
pain ,watery diarrhea and generalised
weakness 3 hrs after herbal broth
In AED
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c/o palpitation and dizziness
BP : 85/49
P: 48/min.,irregular
Temp: 36.5
H’stix : 6.5 mmol/L
Physical Examination
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Conscious
Chest clear
HS dual
Abd : soft, non tender
Muscle power : 5/5 both sides
Jerks were normal
No nystagmus /past-pointing
Neck soft
ECG
Investigation
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ECG : freq ventricular ectopic beats with couplets
PR : 0.11 sec
QRS : 0.075 sec
QTc : 0.448 sec
Na : 143.2 mmol/L
K : 4.03 mmol/L
Venous pH: 7.36
Management in AED.
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Oxygen given
IV NS 500ml FR given
Put on cardiac monitor
CCU was consulted
Possibility of herbal medicine poisoning , the
prescription traced
Prescription
Which is the responsible toxic
ingredient?
草烏 ( Caowu) or aconitine
Progress
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After admission to CCU, BP :108/70
Put on IVF and cardiac monitor
Repeated ECG showed SR with no more vent
ectopic 7 hrs after admission
No antiarrhymic drugs given
Transfer to cardiac ward next day morning
(22/12/04) with symptoms subsided
Remained uneventful
Investigation:
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Hb :11 g/dL
L/RFT essentially normal
Troponin I :not raised
Blood gas : normal
Bedside echocardiogram : satisfactory LV
function
Blood and urine was sent to TRL : aconitine
and deoxyaconitine was detected in the urine
compatible with aconitine poisoning
Aconitine
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Aconitine:
 Highly poisonous C-19 diterpenoid-ester alkaloid.
 Derived from aconite rootstock.
 川烏 ,草烏, 附子, 雪上一枝蒿 in herbal medicine contains
aconitine alkaloids
 Possess anti-inflammatory, analgesic and cardiotonic effect.
 Treatment:
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Rheumatism
Neuralgia
Fever
Cardiac complaint.
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Raw aconite roots:
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Generally toxic
Need possessing before use
Possessing :
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Soaked in water or saturated lime water and boiled
until the aconitine white core disappears
Boiling : hydrolysis of aconitine to less toxic
benzylaconine and aconine derivative
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Aconite alkaloid : very narrow therapueutic
index
Poisoning can be due to:
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Inadequate possessing
Overdose
Inappropriate preparation methods
Toxicity of aconitine.
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Mechanism
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Activate the voltage sensitive Na channels in the
heart , nerves and muscles
Enhance inward Na current during the plateau
phase of action potential
Prolong the repolarization
Premature excitation of cardiac myocites
Both cardiotoxin and neurotoxin
Symptoms of poisoning
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Dizziness
Nausea and vomiting
Parasthesia
Muscle weakness ( interfere neuromuscular transmission)
Hypotension and bradyarrhythmia ( muscarinic effect)
Supravent /vent tachyarrhythmia ( premature excitation)
Death usually due to ventricular arrhythmia
Symptoms onset :a few minutes to 2 hrs
Management of aconitine poisoning .
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Clinical experience remained limited
No antidote available
Rx mainly supportive
Gut decontamination by activated charcoal
may reduce absorption of aconitine
For hypotension: IVF and inotropes
Treatment of ventricular arrhythmia
due to aconitine
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Remained a challenge
Cardioversion and cardiac pacing :probably
not effective
Lignocaine not useful
Amiodarone and flecainide may be reasonable
drugs of first choice
Cardiotoxicity after accidental herb induced
aconite poisoning .
Y.T.Tai et al
Lancet 1992; 340: 1254-56.
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17 patients with aconitine induced cardiotoxicity during 1989-1991 were
treated
All patients Chinese. Median age :56. Only 1 had hx of MI.
2 had VF
13 got VT (sustained and polymorphic)
2 had freq VEB
DC cardioversion :unsuccessful in 10 patients
No single antiarrythmic drugs uniformly effective
Lignocaine :unsuccessful in all patients
Suppression of VT eventually susccessful in 9 patients with amiodarone
(5), flecainide (2), procainamide (1), and mexiletine (1)
2 patients died from refractory VF within 6 hrs of admission
Remaining 15 stabilized within 24 hr
Other case report.
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61 yr man with aconitine induced refractory
VEB successfully treated with amiodarone
(150mg loading ,then 1300mg in 36 hrs) after
failure of lignocaine
DF Yeih, FT Chiang Heart 2000; 84(4): E8
Other treatment option:
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Charcoal haemoperfusion for 4hrs
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Clinical Features and management of herbs induced
aconitine poisoning.
Lin CC et al Annals of Emerg Med 2004 ;43(5):574-9
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Cardiopulmonary bypass.
Ohuchi S. Kyobu Geka 2000;53:541-544
Thank you.
Summary + Comments
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Use of TCM is common in Hong Kong
Aconitine poisoning is most commonly reported
Consider aconitine poisoning as DDx in patients
presenting with paresthesia ,muscle weakness ,
hypotension and vent .dysrrhythmia.
Treatment is mainly supportive
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IVF + Inotropes for hypotension
Amiodarone for tachyarrthymia
Symptoms usually subside within 24 hours