Toxicology (main): Difference between revisions
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==Background== | ==Background== | ||
=== | ===Epidemiology=== | ||
* | *In 2014, ~2.2million human exposures reported to US poison control centers | ||
*Top 5 substance classes: | |||
**analgesics (11%) | |||
* | **cosmetics/personal care products (8%) | ||
** | **household cleaning substances (8%) | ||
** | **sedatives/hypnotics/antipsychotics (6%) | ||
** | **antidepressants (4%) | ||
** | *1,835 human exposures resulted in death | ||
** | |||
* | |||
{{Autonomic nervous system receptors}} | |||
==Clinical Features== | |||
{{Template:Toxidrome Chart}} | {{Template:Toxidrome Chart}} | ||
==Differential Diagnosis for Specific Signs== | ==Differential Diagnosis for Specific Signs== | ||
===Hyperthermia=== | ===[[Hyperthermia]]=== | ||
*Altered Metabolism | *Altered Metabolism | ||
** [[Aspirin (Salicylate) Toxicity]] | **[[Aspirin (Salicylate) Toxicity]] | ||
** withdrawal | **Withdrawal states (e.g. [[baclofen withdrawal]] | ||
** | **[[Thyroid]] hormones | ||
** | **[[Dinitrophenol]]s | ||
* Increased Muscle Activity | *Increased Muscle Activity | ||
** | **Withdrawal, [[sympathomimetics]] | ||
** [[MAOI Toxicity]] | **[[MAOI Toxicity]] | ||
**[[PCP]], LSD | **[[PCP]], [[LSD]] | ||
** [[Lithium]] | **[[Lithium]] | ||
**[[Serotonin Syndrome]] | **[[Serotonin Syndrome]] | ||
* Impaired Heat Dissipation | *Impaired Heat Dissipation | ||
** | **[[Anticholinergics]] | ||
** | **[[Antihistamines]] | ||
** | **[[Antipsychotics]], TCAs | ||
* [[Malignant Hyperthermia]] | **[[Phenothiazines]], [[Lithium]], LevoDopa | ||
** | *[[Malignant Hyperthermia]] | ||
* [[Neuroleptic Malignant Syndrome]] | **Anesthetics | ||
*[[Neuroleptic Malignant Syndrome]] | |||
===Hypothermia=== | ===[[Hypothermia]]=== | ||
* Exposure | *Exposure | ||
** [[Ethanol Toxicity]] | **[[Ethanol Toxicity]] | ||
** Sedative | **[[Sedative/Hypnotics]] | ||
** | **[[Opioids]] | ||
** [[TCAs]] | **[[TCAs]] | ||
** Phenothiazines | **[[Phenothiazines]] | ||
** [[Insulin]] ([[Hypoglycemia]]) | **[[Insulin]] ([[Hypoglycemia]]) | ||
**[[Carbon monoxide]] | |||
===Increased Respiratory Rate=== | ===Increased Respiratory Rate=== | ||
* Direct | *Direct stimulation | ||
** [[Aspirin (Salicylate) Toxicity]] | **[[Aspirin (Salicylate) Toxicity]] | ||
** [[Metabolic Acidosis]] | **[[Metabolic Acidosis]] | ||
** | **[[Dinitrophenol]], pentachlorophenol | ||
** | **[[Hepatic failure|hepatic]]/[[renal failure]] | ||
** CNS stimulants (cocaine, | **CNS stimulants ([[cocaine]], [[amphetamine]], [[theophylline]]) | ||
*Tissue [[Hypoxia]] | *Tissue [[Hypoxia]] | ||
**[[CO]] | **[[CO]] | ||
Line 79: | Line 60: | ||
**[[Methemoglobinemia]] | **[[Methemoglobinemia]] | ||
===Respiratory Depression=== | ===[[Respiratory failure|Respiratory Depression]]=== | ||
* Central Depression | *Central Depression | ||
** | **[[Antipsychotics]] | ||
** Chlorinated hydrocarbons | **Chlorinated [[hydrocarbons]] | ||
** [[Sedative/Hypnotics]] ([[Ethanol Toxicity]], glycols) | **[[Sedative/Hypnotics]] ([[Ethanol Toxicity]], glycols) | ||
** [[Tricyclic (TCA) Toxicity]] | **[[Tricyclic (TCA) Toxicity]] | ||
** | **[[Lomotil toxicity]] | ||
* Muscle Failure | **[[Opioids]] | ||
** [[Organophosphates]] | **[[Marijuana]] | ||
*Muscle Failure | |||
**[[Organophosphates]] | |||
**[[Marine Toxins]] | **[[Marine Toxins]] | ||
** [[Nicotine Poisoning|Nicotine]] | **[[Nicotine Poisoning|Nicotine]] | ||
** | **[[Strychnine]] | ||
** | **[[Botulism]] | ||
** Mojave rattlesnake, Cobra | **Mojave [[rattlesnake]], Cobra | ||
===[[Bradycardia]]=== | |||
PACED | |||
*[[Propranolol]]/[[beta-blockers]], poppies ([[opiates]]), propoxyphene, | |||
[[physostigmine]] | |||
*[[Acetylcholinesterase inhibitors|Anticholinesterases]], [[antiarrhythmics]] | |||
*[[Clonidine]], [[calcium channel blockers]] | |||
*[[Ethanol]] or other [[toxic alcohols|alcohols]] | |||
*[[Digoxin]], [[digitalis]] | |||
===[[Tachycardia]]=== | |||
FAST | |||
*Free base or other forms of [[cocaine]] | |||
*[[Anticholinergics]], [[antihistamines]], [[antipsychotics]], [[amphetamines]], [[alcohol withdrawal]] | |||
*[[Sympathomimetics]] (cocaine, caffeine, amphetamines, PCP), solvent abuse, strychnine | |||
*[[Theophylline]], [[TCA]], [[thyroid]] hormones | |||
===Hypotension=== | |||
CRASH | |||
*[[Clonidine]], [[calcium channel blockers]] | |||
*Rodenticides (with [[arsenic]], [[cyanide]]) | |||
*Antidepressants, [[aminophylline]], [[antihypertensives]] | |||
*[[Sedative/Hypnotics]] | |||
*[[Heroin]] or other [[opioids]] | |||
===[[Hypertension]]=== | |||
CT SCAN | |||
*[[Cocaine]] | |||
*[[Thyroid]] supplements | |||
*[[Sympathomimetics]] | |||
*[[Caffeine]] | |||
*[[Anticholinergics]], [[amphetamines]] | |||
*[[nicotine toxicity|Nicotine]] | |||
===Miosis=== | |||
COPS | |||
*[[Cholinergic]]s, [[clonidine]], [[carbamates]] | |||
*[[Opioids]], [[organophosphates]] | |||
*[[Phenothiazines]], pilocarpine, pontine hemorrhage | |||
*[[Sedative/Hypnotics]] | |||
===Mydriasis=== | |||
SAW | |||
*[[Sympathomimetics]] | |||
*[[Anticholinergics]] | |||
*Withdrawal syndromes | |||
===[[Coma]]=== | |||
LETHARGIC | |||
*[[Lead]], [[lithium]] | |||
*[[Ethanol]], [[Ethylene glycol toxicity|ethylene glycol]] | |||
*[[TCA]], [[thallium]], [[toluene]] | |||
*[[Heroin]], hemlock, [[hepatic encephalopathy]], [[heavy metals]], [[hydrogen sulfide]], hypoglycemics | |||
*[[Arsenic]], antidepressants, [[anticonvulsants]], [[antipsychotics]], [[antihistamines]] | |||
*[[Rohypnol]], [[risperidone]] | |||
*[[GHB]] | |||
*[[Isoniazid]], [[insulin]] | |||
*[[Carbon monoxide]], [[cyanide]], [[clonidine]] | |||
===[[Seizures]]=== | |||
OTIS CAMPBELL | |||
*[[Organophosphates]], oral hypoglycemics (e.g. [[sulfonylurea]]) | |||
*[[TCA]], [[theophylline]], [[tramadol]] | |||
*[[Isoniazid]], [[Insulin]] | |||
*[[Sympathomimetics]], [[salicylates]], [[strychnine]] | |||
*[[Camphor toxicity|Camphor]], [[carbon monoxide]], [[cyanide]], chlorinated [[hydrocarbons]], [[cocaine]] | |||
*[[Anticholinergics]] (antihistamines), [[amphetamines]], antidepressants (citalopram, [[Tricyclic antidepressant toxicity|TCAs]], [[bupropion]]) | |||
*[[Methanol]], Methylxanthines ([[theophylline]], [[caffeine]]), [[MAOI Toxicity|MAOI]] | |||
*[[PCP]], [[propranolol]] | |||
*[[Benzodiazepine withdrawal]], [[bupropion]], botanicals (hemlock, [[nicotine toxicity|nicotine]]), [[GHB]] | |||
*[[ETOH withdrawal]], [[ethylene glycol]] | |||
*[[Lead]], [[lithium]] | |||
*[[Lidocaine]], [[lindane]] (pesticide, scabies) | |||
===Skin findings=== | |||
====Diaphoresis==== | |||
SOAP | |||
*[[Sympathomimetics]] | |||
*[[Organophosphates]] | |||
*[[Acetylsalicylic acid]] and other salicylates | |||
*[[Phencyclidine toxicity|PCP]] | |||
====Dry skin==== | |||
*[[Antihistamines]], [[anticholinergics]] | |||
====Bullous lesions/blisters==== | |||
*[[Barbiturates]] | |||
*[[Mustard agent (vesicants|Mustard gas]] | |||
*[[Snake bites|Snakes]] and [[spider bites|spiders]] | |||
====Flushed/red appearance==== | |||
*[[Anticholinergics]] | |||
*[[Niacin]] | |||
*Boric acid | |||
*[[Carbon monoxide]] | |||
*[[Cyanide]] | |||
====Cyanosis==== | |||
*[[Benzocaine]] and other local anesthetics | |||
*[[Cyanokit]], nitrites, nitrates, well water (nitrates) | |||
*[[Antimalarials]] | |||
*[[Quinolones]] | |||
*[[Dapsone]] (used to treat leprosy, PCP pneumonia, toxoplasmosis, dermatitis herpetiformis, brown recluse bite) | |||
*Aniline dyes | |||
*Phenazopyridine<ref>Jeffery WH, Zelicoff AP, Hardy WR. Acquired methemoglobinemia and hemolytic anemia after usual doses of phenazopyridine. Drug Intell Clin Pharm. 1982 Feb;16(2):157-9.</ref> | |||
*Nitrates, nitrites | |||
*Ergotamine toxicity|Ergotamine]] | |||
====Acneiform [[rash]]==== | |||
*Bromides | |||
*Chlorinated aromatic [[hydrocarbons]] | |||
==Evaluation== | |||
===Toxicological Exam=== | |||
*All vital signs (Temp, RR, HR, BP) + bedside glucose | |||
*[[Neurologic exam]] | |||
**Level of consciousness | |||
**Pupillary exam | |||
**Motor response | |||
**DTRs | |||
*Skin Exam - moisture, temp, evidence of injection drug abuse | |||
*Lung Exam | |||
*Bowel Sounds | |||
*[[ECG]] (ie. look for [[QT prolongation]], QRS prolongation, etc) | |||
*Consider CBC, BMP, urinalysis (with ẞ-HCG if appropriate), urine toxicology screen, serum alcohol concentration, VBG | |||
**The urine screen is a qualitative test -> positivity ≠ acute toxicity | |||
**It can be falsely positive due to cross-reactivity | |||
**It can be falsely negative if the substance ingested does not cross-react with the tested analyte | |||
**The diagnosis of intoxication is clinical!!! | |||
==Management== | |||
*Depends on agent | |||
*See [[antidotes]] | |||
*"Coma cocktail" when suspecting toxic ingestion (mnemonic = "DONT") | |||
*#[[Dextrose]] (50mg IV) | |||
*#[[Oxygen]] | |||
*#[[Naloxone]] (0.2-0.4mg IV/IM, repeat dose 1-2mg) | |||
*#*Empiric opioid ingestion treatment | |||
*#[[Thiamine]] (50-100mg) | |||
*#*Treat or avoid [[Wernicke encephalopathy]] | |||
*#*Though some suggest giving thiamine prior to dextrose, do NOT let this delay treatment of hypoglycemia! | |||
*#*Case reports of dextrose precipitating Wernicke's involved thiamine-deficient patients receiving prolonged course of IV glucose, NOT with single bolus<ref>Donnino MW, Vega J, Miller J, Walsh M. Myths and misconceptions of Wernicke's encephalopathy: what every emergency physician should know. Ann Emerg Med. 2007;50(6):715-21.</ref><ref>Gussow, L. Myths of Toxicology: Thiamine Before Dextrose. Emergency medicine news. 2007;29(4):3-11.</ref> | |||
==Disposition== | |||
*Depends on agent | |||
==See Also== | ==See Also== | ||
Line 98: | Line 221: | ||
*[[Traditional chinese medicine toxicology]] | *[[Traditional chinese medicine toxicology]] | ||
*[[Drug_levels|Drug Levels]] | *[[Drug_levels|Drug Levels]] | ||
*[[Antidote]] | |||
*[[Camphor toxicity]] | |||
*[[In-Training Exam Review]] | |||
==References== | ==References== |
Latest revision as of 19:18, 20 February 2021
Background
Epidemiology
- In 2014, ~2.2million human exposures reported to US poison control centers
- Top 5 substance classes:
- analgesics (11%)
- cosmetics/personal care products (8%)
- household cleaning substances (8%)
- sedatives/hypnotics/antipsychotics (6%)
- antidepressants (4%)
- 1,835 human exposures resulted in death
Autonomic Nervous System Receptors and Their Effects
- Parasympathetic - ACh is transm
- Muscarinic
- receptors in heart, eye, lung, GI, skin and sweat glands
- Bradycardia
- Miosis
- Bronchorrhea / Bronchospasm
- Hyperperistalsis (SLUDGE)
- Sweating
- Vasodilation
- Nicotinic
- receptors in both sympathetic and parasympathetic nervous systems
- fasciculations, flaccid paralysis
- ?Mild bradycardia, hypotension
- Muscarinic
- Sympathetic
- Alpha effects (vessels, eye, skin)
- Mydriasis, hypertension, sweating
- Beta effects (heart, lungs)
- Tachycardia, bronchodilation
- Alpha effects (vessels, eye, skin)
Clinical Features
Toxidrome Chart
Finding | Cholinergic | Anticholinergic | Sympathomimetic | Sympatholytic^ | Sedative/Hypnotic |
Example | Organophosphates | TCAs | Cocaine | Clonidine | ETOH |
Temp | Nl | Nl / ↑ | Nl / ↑ | Nl / ↓ | Nl / ↓ |
RR | Variable | Nl / ↓ | Variable | Nl / ↓ | Nl / ↓ |
HR | Variable | ↑ | ↑ (sig) | Nl / ↓ | Nl / ↓ |
BP | ↑ | ↑ | ↑ | Nl / ↓ | Nl / ↓ |
LOC | Nl / Lethargic | Nl, agitated, psychotic, comatose | Nl, agitated, psychotic | Nl, Lethargic, or Comatose | Nl, Lethargic, or Comatose |
Pupils | Variable | Mydriatic | Mydriatic | Nl / Miotic | |
Motor | Fasciculations, Flacid Paralysis | Nl | Nl / Agitated | Nl | |
Skin | Sweating (sig) | Hot, dry | Sweating | Dry | |
Lungs | Bronchospasm / rhinorrhea | Nl | Nl | Nl | |
Bowel Sounds | Hyperactive (SLUDGE) | ↓ / Absent | Nl / ↓ | Nl / ↓ |
- ^Consider Sympatholytic when looking at Sedative OD or someone who doesn't respond to Narcan
- Withdrawal from substances have the opposite effect
Differential Diagnosis for Specific Signs
Hyperthermia
- Altered Metabolism
- Aspirin (Salicylate) Toxicity
- Withdrawal states (e.g. baclofen withdrawal
- Thyroid hormones
- Dinitrophenols
- Increased Muscle Activity
- Withdrawal, sympathomimetics
- MAOI Toxicity
- PCP, LSD
- Lithium
- Serotonin Syndrome
- Impaired Heat Dissipation
- Anticholinergics
- Antihistamines
- Antipsychotics, TCAs
- Phenothiazines, Lithium, LevoDopa
- Malignant Hyperthermia
- Anesthetics
- Neuroleptic Malignant Syndrome
Hypothermia
- Exposure
Increased Respiratory Rate
- Direct stimulation
- Aspirin (Salicylate) Toxicity
- Metabolic Acidosis
- Dinitrophenol, pentachlorophenol
- hepatic/renal failure
- CNS stimulants (cocaine, amphetamine, theophylline)
- Tissue Hypoxia
Respiratory Depression
- Central Depression
- Antipsychotics
- Chlorinated hydrocarbons
- Sedative/Hypnotics (Ethanol Toxicity, glycols)
- Tricyclic (TCA) Toxicity
- Lomotil toxicity
- Opioids
- Marijuana
- Muscle Failure
- Organophosphates
- Marine Toxins
- Nicotine
- Strychnine
- Botulism
- Mojave rattlesnake, Cobra
Bradycardia
PACED
- Propranolol/beta-blockers, poppies (opiates), propoxyphene,
- Anticholinesterases, antiarrhythmics
- Clonidine, calcium channel blockers
- Ethanol or other alcohols
- Digoxin, digitalis
Tachycardia
FAST
- Free base or other forms of cocaine
- Anticholinergics, antihistamines, antipsychotics, amphetamines, alcohol withdrawal
- Sympathomimetics (cocaine, caffeine, amphetamines, PCP), solvent abuse, strychnine
- Theophylline, TCA, thyroid hormones
Hypotension
CRASH
- Clonidine, calcium channel blockers
- Rodenticides (with arsenic, cyanide)
- Antidepressants, aminophylline, antihypertensives
- Sedative/Hypnotics
- Heroin or other opioids
Hypertension
CT SCAN
- Cocaine
- Thyroid supplements
- Sympathomimetics
- Caffeine
- Anticholinergics, amphetamines
- Nicotine
Miosis
COPS
- Cholinergics, clonidine, carbamates
- Opioids, organophosphates
- Phenothiazines, pilocarpine, pontine hemorrhage
- Sedative/Hypnotics
Mydriasis
SAW
- Sympathomimetics
- Anticholinergics
- Withdrawal syndromes
Coma
LETHARGIC
- Lead, lithium
- Ethanol, ethylene glycol
- TCA, thallium, toluene
- Heroin, hemlock, hepatic encephalopathy, heavy metals, hydrogen sulfide, hypoglycemics
- Arsenic, antidepressants, anticonvulsants, antipsychotics, antihistamines
- Rohypnol, risperidone
- GHB
- Isoniazid, insulin
- Carbon monoxide, cyanide, clonidine
Seizures
OTIS CAMPBELL
- Organophosphates, oral hypoglycemics (e.g. sulfonylurea)
- TCA, theophylline, tramadol
- Isoniazid, Insulin
- Sympathomimetics, salicylates, strychnine
- Camphor, carbon monoxide, cyanide, chlorinated hydrocarbons, cocaine
- Anticholinergics (antihistamines), amphetamines, antidepressants (citalopram, TCAs, bupropion)
- Methanol, Methylxanthines (theophylline, caffeine), MAOI
- PCP, propranolol
- Benzodiazepine withdrawal, bupropion, botanicals (hemlock, nicotine), GHB
- ETOH withdrawal, ethylene glycol
- Lead, lithium
- Lidocaine, lindane (pesticide, scabies)
Skin findings
Diaphoresis
SOAP
- Sympathomimetics
- Organophosphates
- Acetylsalicylic acid and other salicylates
- PCP
Dry skin
Bullous lesions/blisters
Flushed/red appearance
- Anticholinergics
- Niacin
- Boric acid
- Carbon monoxide
- Cyanide
Cyanosis
- Benzocaine and other local anesthetics
- Cyanokit, nitrites, nitrates, well water (nitrates)
- Antimalarials
- Quinolones
- Dapsone (used to treat leprosy, PCP pneumonia, toxoplasmosis, dermatitis herpetiformis, brown recluse bite)
- Aniline dyes
- Phenazopyridine[1]
- Nitrates, nitrites
- Ergotamine toxicity|Ergotamine]]
Acneiform rash
- Bromides
- Chlorinated aromatic hydrocarbons
Evaluation
Toxicological Exam
- All vital signs (Temp, RR, HR, BP) + bedside glucose
- Neurologic exam
- Level of consciousness
- Pupillary exam
- Motor response
- DTRs
- Skin Exam - moisture, temp, evidence of injection drug abuse
- Lung Exam
- Bowel Sounds
- ECG (ie. look for QT prolongation, QRS prolongation, etc)
- Consider CBC, BMP, urinalysis (with ẞ-HCG if appropriate), urine toxicology screen, serum alcohol concentration, VBG
- The urine screen is a qualitative test -> positivity ≠ acute toxicity
- It can be falsely positive due to cross-reactivity
- It can be falsely negative if the substance ingested does not cross-react with the tested analyte
- The diagnosis of intoxication is clinical!!!
Management
- Depends on agent
- See antidotes
- "Coma cocktail" when suspecting toxic ingestion (mnemonic = "DONT")
- Dextrose (50mg IV)
- Oxygen
- Naloxone (0.2-0.4mg IV/IM, repeat dose 1-2mg)
- Empiric opioid ingestion treatment
- Thiamine (50-100mg)
- Treat or avoid Wernicke encephalopathy
- Though some suggest giving thiamine prior to dextrose, do NOT let this delay treatment of hypoglycemia!
- Case reports of dextrose precipitating Wernicke's involved thiamine-deficient patients receiving prolonged course of IV glucose, NOT with single bolus[2][3]
Disposition
- Depends on agent
See Also
- Altered mental status
- Traditional chinese medicine toxicology
- Drug Levels
- Antidote
- Camphor toxicity
- In-Training Exam Review
References
- ↑ Jeffery WH, Zelicoff AP, Hardy WR. Acquired methemoglobinemia and hemolytic anemia after usual doses of phenazopyridine. Drug Intell Clin Pharm. 1982 Feb;16(2):157-9.
- ↑ Donnino MW, Vega J, Miller J, Walsh M. Myths and misconceptions of Wernicke's encephalopathy: what every emergency physician should know. Ann Emerg Med. 2007;50(6):715-21.
- ↑ Gussow, L. Myths of Toxicology: Thiamine Before Dextrose. Emergency medicine news. 2007;29(4):3-11.