PEARLS AND PITFALLS
- Ipecac has no utility in the ED.
- Administer activated charcoal in almost every toxic ingestion that presents within 1 hr with a patent airway
- Never use multiple doses of cathartic in conjunction with multiple-dose activated charcoal.
ADDITIONAL READING
- Albertson TE, Owen KP, Sutter ME, et al. Gastrointestinal decontamination in the acutely poisoned patient.
Int J Emerg Med.
2011;4:65.
- Holstege CP, Dopmeier SG, Bechtel LK. Critical Care Toxicology Emergency Medicine Clinics of North America – Volume 26, Issue 3 (August 2008).
- Isbister GK, Kumar VV. Indications for single-dose activated charcoal administration in acute overdose.
Curr Opin Crit Care
. 2011;17(4):351—357.
See Also (Topic, Algorithm, Electronic Media Element)
- Poisoning
- Poisoning, Antidotes
- Poisoning, Toxidromes
CODES
ICD9
977.9 Poisoning by unspecified drug or medicinal substance
ICD10
T65.91XA Toxic effect of unspecified substance, accidental (unintentional), initial encounter
POISONING, TOXIDROMES
Michael S. Wahl
BASICS
DESCRIPTION
- A toxidrome is the constellation of signs and symptoms that result from the effects of a particular toxin (toxic syndrome)
- Mechanism of action varies with each class of toxin to which the patient may be exposed and the target receptors.
DIAGNOSIS
SIGNS AND SYMPTOMS
Toxidromes
- There are multiple toxidromes:
- Anticholinergic
- Cholinergic
- Sympathomimetic
- Hallucinogenic
- Opiate
- Sedative–hypnotic
- Withdrawal syndromes
- Serotonin syndrome
- Malignant neuroleptic syndrome
- Anticholinergic:
Mnemonic:
“Blind as a bat, mad as a hatter, red as a beet, hot as a hare, dry as a bone, the bowel and bladder lose their tone, and the heart runs alone”:
- Hyperthermia (“hot as a hare)
- Dry, flushed skin (“dry as a bone” and “red as a beet”)
- Dilated pupils (“blind as a bat”)
- Delirium (“mad as a hatter”)
- Tachycardia (“the heart runs alone”)
- Hypertension
- Hyperthermia
- Urgency retention (“bowel and bladder lose their tone”)
- Decreased bowel sounds (“bowel and bladder lose their tone”)
- Seizures
- Mental status changes
- Somnolence
- Cholinergic:
Mnemonic:
DUMBELS for the muscarinic component:
- Muscarinic signs:
- D
iarrhea, diaphoresis
- U
rination
- M
iosis
- B
radycardia, bronchorrhea, bronchospasm (the killer Bs)
- E
mesis
- L
acrimation
- S
alivation
- Nicotinic signs:
- Mydriasis
- Tachycardia
- Weakness
- Hypertension
- Fasciculations
- Sympathomimetic:
Similar to anticholinergic presentation except for skin and bowel differences (diaphoresis and increased bowel sounds may be present in sympathomimetic presentations):
- Diaphoresis
- Mydriasis
- Tachycardia
- Hypertension
- Hyperthermia
- Seizures
- Increased peristalsis
- Hallucinogenic:
May have significant overlap with sympathomimetic toxidrome as many sympathomimetic drugs have hallucinogenic properties (e.g., MDMA/ecstasy, cathinones, hallucinogenic amines). Other hallucinogens include LSD, psilocybin, peyote, mescaline:
- Disorientation
- Hallucinations
- Anxiety
- Panic
- Seizures
- Opiate:
- Classic triad:
- Miosis
- Hypoventilation
- Coma
- May also present with:
- Bradycardia
- Hypotension
- Hypothermia
- Decreased bowel sounds
- Sedative–hypnotics and alcohol:
- Sedation
- Mental status changes (confusion, delirium, hallucinations)
- Vision changes (blurred vision, diplopia)
- Slurred speech
- Ataxia
- Nystagmus
- Withdrawal
(alcohol, benzodiazepine, barbiturates):
- Mydriasis
- Tachycardia
- Hypertension
- Hyperthermia
- Increased respiratory rate
- Diaphoresis
- Increased bowel sounds
- Tremor
- Agitation
- Anxiety
- Hallucinations
- Confusion
- Seizures
- Withdrawal
(opioid):
- Nausea
- Vomiting
- Diarrhea
- Abdominal cramps
- Increased bowel sounds
- Mydriasis
- Piloerection
- Tachycardia
- Lacrimation
- Salivation
- Hypertension
- Yawning
- Neuroleptic malignant syndrome:
- Recent treatment with typical and atypical antipsychotic medications:
- Generally occurs from hours to several weeks of starting or increasing the dose of a medication, but can occur at any time.
- Hyperthermia
- Muscular rigidity
- Diaphoresis
- Mental status changes
- Hypertension or hypotension may be seen
- Sialorrhea
- Tremor
- Incontinence
- Increased creatinine phosphokinase
- Leukocytosis
- Metabolic acidosis
- Serotonin syndrome:
- Occurs soon after the increase in dose or addition of serotonergic medications.
- Syndrome with variable presentation
- Following are most common, seen 25–57% of the time:
- Mental status changes (confusion, agitation, hypomania, lethargy)
- Seizures
- Myoclonus
- Hyperreflexia
- Muscle rigidity
- Tremor
- Nystagmus
- Hyperthermia
- Diaphoresis
- Tachycardia
- Hypertension
- Mydriasis
Physical-Exam
- Bradycardia:
- α
2
-adrenergic agonists (e.g., clonidine)
- β-blockers
- Calcium-channel blockers
- Digoxin and related substances
- Cholinergics
- Opioids
- Tachycardia:
- Sympathomimetics
- Anticholinergics
- Methylxanthines
- Tricyclic antidepressant
- Withdrawal
- Phenothiazines
- Atypical antipsychotics
- α
1
-blockade with reflex tachycardia
- Phosphodiesterase type 5 inhibitor (e.g., Sildenafil)
- Hyperthermia:
- Anticholinergics
- Sympathomimetics
- Serotonin syndrome
- Neuroleptic malignant syndrome
- Malignant hyperthermia
- Dinitrophenol
- Salicylates
- Withdrawal
- Hypothermia:
- Carbon monoxide
- Oral hypoglycemics
- Opiates
- Ethanol
- Sedative–hypnotics
- α
2
-adrenergic agonists
- Hypertension:
- Sympathomimetics
- Anticholinergics
- Nicotine
- Phencyclidine (PCP)
- Ergot alkaloids
- Hypotension:
- α
2
-agonists
- α
1
-antagonists
- β-blockers
- Calcium-channel blockers
- Angiotensin converting–enzyme inhibitors
- Methylxanthines
- Nitrates
- Opioids
- Phenothiazines
- Phosphodiesterase type 5 inhibitors
- Sedative–hypnotics
- Ethanol
- Tricyclic antidepressants
- Atypical antipsychotic medications
- Miosis:
- Cholinergics
- Clonidine
- Reserpine
- Phenothiozines
- Atypical antipsychotics
- Mydriasis:
- Anticholinergics
- Sympathomimetics
- Withdrawal (esp. opioids)
- Botulism
- Seizures:
Mnemonic with a limited list of causes for toxic seizures
OTIS CAMPBELL:
- O
rganophosphates
- T
ricyclic antidepressants
- I
soniazid, insulin
- S
ympathomimetics, salicylates
- C
amphor, cocaine, citalopram
- A
mphetamines, anticholinergic agents
- M
ethylxanthines (theophylline, caffeine), mushrooms (
Gyromitra:
monomethyl hydrazine group), meperidine
- P
CP, propoxyphene, plants (nicotine, water hemlock)
- B
enzodiazepine withdrawal, bupropion
- E
thanol withdrawal
- L
ithium, lidocaine
- L
ead, lindane
- Diaphoresis:
- Sympathomimetics
- Cholinergics
- Salicylates
- Withdrawal
- Serotonin syndrome
- Bradypnea:
- Opiates
- Sedative–hypnotics
- Ethanol
- γ-hydroxybutyric acid and congeners
- Botulism
- Muscular receptor blockade
- Tachypnea:
- Paraquat (and other drugs that cause pneumonitis)
- Salicylates
- Sympathomimetics
- Dinitrophenol
- Methylxanthines
- Drugs that cause acidosis