Transcript TMH AED Cardiac Arrest Cases

Case of Lomotil Overdose
Dr. Wong Oi Fung
AED TMH
Case
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M/2
Good past health
17 March 2005 22:29
Ingestion of 5 tablets of Lomotil at 10:30
Witnessed by another child
M/2 Lomotil ingestion
• No convulsion
• No vomiting
• Normal urine output
Physical exmination
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Temp 36°C
GCS 15/15, Pupils equal and reactive
Regular pulse, 139 beats/min
Chest clear
Abdomen soft and non tender, bowel
sound +ve
M/2 Lomotil ingestion - Ix
• AXR: no dilated bowel
• H’stix: 5.4
• ECG SR
Lomotil poisoning in child
Management?
Lomotil poisoning
• Common antidiarrheal agent
• 2.5mg diphenoxylate + 0.025mg atropine
• One of the agents that can kill at a low
dose in pediatric group of patient
– Calcium channel antagonists, camphor,
clonidine and the imidazolines, cyclic
antidepresants, opioids, lomotil, salicylates,
sulfonylureas, toxic alcohols
– Joshua B. Deadly pediatric poisons: nine common agents that kill at low
doses. Emerg Med Clin N Am 22(2004)1019-1050
Clinical Effects
• Rapid absorption by GI tract
• Biphasic: 2-3 hr-antimuscarinic, recover apparently then opioid
symptoms
• Anticholinergic effect:
– Hot as a hare hyperthermia
– Dry as a bone dry skin
– Blind as a bat dilated pupils
– Med as a hatter delirium, hallucination, iirritability
– + tachycardia, urinary retention, decreased bronchosecretion
• Opioid effects:
– CNS and respiratory depression
• Recurrence of symptoms due to active metabolite or return of gastric
function
• The lowest published fatal dose1.2mg/kg (Liebelt & Shannon,
1993)
• The lowest toxic doses 0.5 to 2 tablets (Liebelt & Shannon, 1993)
Pharmacokinetics
GI TRACT
Diphenoxylate Ester hydrolysis
Difenoxine (5 times more active)
Peak plasma
concentrations2hrs
Vol. of
distribution3.8L/kg
t1/2 2.5 hours
49% of dose excreted in
feces
13.7% excreted as free
drug and metabolites in
urine, over 96%
Only 0.4% excreted
unchanged in urine
Atropine
Peak plasma conc. 2hrs
Soluble and excreted into bile
Serum t1/2 4.4hrs
Elimination t1/212 to 14hrs
Anticholingeric
effectopioid effect
Lomotil overdose
• Review of 28 cases in literature
– 4 aspiration pneumonia
– 1 cortical blindness
– 3 cerebral edema and died
• 7 cases: Respiratory depression recurred 13-24hr after ingestion
• 2 cases: pills found in gastric lavage fluid 15 and 17 hours after
ingestion
• 4/36 (11%) showed atropinism followed by signs of opioid overdose
• 21/36(58%) had atropinism before, during or after opioid symptoms
• 15/42(42%) had only opioid symptoms
• In most cases, CNS and resp. depression occurred ~15 to 18hrs
after ingestion( accumulation of active long-acting opioid metabolite)
Diphenoxylate-Atropine overdose in children: An update(Report of eight cases and review
of the literature). Pediatrics Vol. 87 No5 May 1991
Management
• Resuscitation
• ? Delayed gut decontamination
• Naloxone for narcotic symptoms (0.4 to
2mg +/-infusion)
• Physostigmine (0.02mg/kg up to 0.5mg)
– To reverse severe anticholingic symptoms but
rarely required
• Close observation for 24 hours for delayed
symptoms
Lomotil poisoning- outcome
• Admitted to P&A for cardiac monitor and
neuro-observation
• Discharged 12 hours after admission
Take home message
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Few tablets of lomotil can kill
Be aware of delayed opioid effect
Treat life-threatening condition
Close monitoring for at least 24 hours is
necessary
THANK YOU