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:
    • Diarrhea, diaphoresis
    • Urination
    • Miosis
    • Bradycardia, bronchorrhea, bronchospasm (the killer Bs)
    • Emesis
    • Lacrimation
    • Salivation
  • Nicotinic signs (M, T, W, tH, F):
    • 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
• Opioid:
  • 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
  • Usually occurs within hours to a few days after addition or increase of serotonergic medication
  • 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

• Bradycardia:
  • α₂-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
  • α₁-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
  • Opioids
  • Ethanol
  • Sedative-hypnotics
  • α₂-adrenergic agonists
• Hypertension:
  • Sympathomimetics
  • Anticholinergics
  • Nicotine
  • Phencyclidine (PCP)
  • Ergot alkaloids
• Hypotension:
  • α₂-agonists
  • α₁-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
  • Alpha 2 adrenergic agonists (e.g., clonidine,reserpine, guanidine)
  • Phenothiazines
  • Atypical antipsychotics
• Mydriasis:
  • Anticholinergics
  • Sympathomimetics
  • Withdrawal (esp. opioids)
  • Botulism
• Seizures: Mnemonic with a limited list of causes for toxic seizures OTIS CAMPBELL:
  • Organophosphates
  • Tricyclic antidepressants
  • Isoniazid, insulin
  • Sympathomimetics, salicylates, SSRI
  • Camphor, cocaine,
  • Amphetamines, anticholinergic agents
  • Methylxanthines (theophylline, caffeine), mushrooms (Gyromitra: Monomethyl hydrazine group), meperidine
  • PCP, propoxyphene, plants (nicotine, water hemlock)
  • Benzodiazepine withdrawal, bupropion
  • Ethanol withdrawal
  • Lithium, lidocaine
  • Lead, lindane
• Diaphoresis:
  • Cholinergics, salicylates, serotonin syndrome
  • Sympathomimetics withdrawal
• Bradypnea:
  • Opioids
  • Sedative-hypnotics
  • Ethanol
  • -hydroxybutyric acid and congeners
  • Botulism
  • Muscular receptor blockade
• Tachypnea:
  • Paraquat (and other drugs that cause pneumonitis)
  • Salicylates
  • Sympathomimetics
  • Dinitrophenol
  • Methylxanthines
  • Drugs that cause acidosis