What Are Common Toxidromes?

Patient Presentation
A 30-month-old male was transferred to the inpatient unit at a regional children’s hospital for worsening clinical condition. The night before admission, the father said the patient fell off the back of a couch hitting his head on a chair and/or floor. The child then went limp and was lethargic. While emergency medical services was enroute, the child began to flutter his eyes and have several episodes of emesis. At the local emergency room, his initial laboratory tests were normal except for a glucose of 200 mg/dl and potassium of 2.8 mg/dl. A computed tomography examination of the head was negative. He was admitted locally but began to have more gagging and was not coherent or consistently arousable. The past medical history included croup. The family history included a sister with seizures and other family members with asthma and diabetes The review of systems was negative.

The pertinent physical exam showed a lethargic appearing male who became somewhat agitated with handling. He had normal growth parameters and vital signs. HEENT showed intermittent eye opening without direct gaze or tracking. Pupils were 3 mm and reactive. Abdomen revealed decreased bowel sounds. Neurological examination showed he was unable to hold his head without support and had marked truncal ataxia. There was decreased tone and normal deep tendon reflexes. Repeat laboratory evaluation was normal. When the family arrived, they mentioned that they had been unable to find the sister’s Tegretol®. The patient’s Tegretol level was drawn about 8 hours after arrival at the local emergency room and was found to be 17.4 mg/L. (normal = 4-12 mg/L.) and diagnosis of a Tegretol overdose was made. The patient was treated with close monitoring and hydration. The patient’s clinical course showed that he was back to his normal baseline at 36 hours. The outside hospital and children’s hospital urine toxicology testing was negative. As there was a complicated social history and other children in the home with injuries (e.g. accidental broken bones and another overdose in other children), the Department of Human Services was contacted and agreed with discharge home but they were planning on investigating the home situation within 48 hours.

Treatment for toxicologic emergencies initially includes the traditional ABC’s of airway, breathing and circulation management. “D” includes drugs such as glucose, naloxone, thiamine, hydration and oxygen, and disability treatment (or neurological status, some say “Da Brain”) such as fluid management, hyperventilation, etc. “D” in toxicological emergencies also includes decontamination including gastric lavage, syrup of ipecac, activated charcoal, and bowel cathartics. Although antidotes do exist, there are relatively few for the plethora of potential toxic substances. Supportive treatment is a mainstay including fluid management (i.e. hydration, acidification/alkalinazation, diuresis, and dialysis), electrolyte management (i.e. glucose, calcium and potassium management), respiratory management, and an antidote if available.

The social history is important in all toxicologic emergencies. Accidental overdose is usually the most common reason for a toxicologic emergency in young children and brings up the issue of possible child neglect. Older children and teens may attempt suicide necessitating psychiatric consultation and social service implementation. Forced ingestion may reveal issues of coercion, and even attempted battery, rape or murder. Occupational or recreational exposure may bring to light general safety standards.

Carbamazepine (Tegretol®) is a common anti-epileptic medication. Peak plasma levels occur 6-24 hours after ingestion.

  • Carbamazepine overdose
    • Most Common Presentation
      • Mental Status – altered
      • Neuromuscular – seizure, dystonia
      • Lung – depression or apnea
      • Eyes – ophthamoplegia
      • Skin – hypo- or hyperthermia
    • Other Common Problems
      • Lung – edema
      • Skin – idiosyncratic reactions
      • GI/GU – decreased bowel sounds, decreased bowel emptying
      • Other – SIADH
    • Agent – carmamazepine
    • Treatment – support, hemodialysis

Learning Point
Toxidromes are poisoning patterns or constellations of physical examination findings that are found because of a toxic dose of a medication, drug or toxin. Common toxidromes include:

  • Anticholinergic
    • Most Common Presentation
      • Mental Status – altered
      • Eyes – midriasis
      • Skin – dry, flushed, hyperthermia, dry mucous membranes
      • GI/GU – decreased bowel sounds, urinary retension
    • Other Common Problems
      • Mental Status – seizures
      • Neuromuscular – rhabdomyolysis
      • Heart – dysrhythmias
    • Agent – antihistamines, atropine, scopolamine, tricyclic antidepressants
    • Treatment – physostigmine, sedation, cooling
  • Cholinergic
    • Most Common Presentation
      • Neuromuscular – muscle fasciculations, weakness
      • Lung – respiratory secretions
      • Skin – lacrimination, salivation
      • GI/GU – nausea, emesis, increased stooling and urination
    • Other Common Problems
      • Mental Status – seizures
      • Neuromuscular – paralysis
      • Heart – bradycardia
      • Lung – respiratory failure
      • Eyes – miosis, mydriasis
    • Agent – insecticides including carbamate, organophosphate, mushrooms
    • Treatment – atropine, pralidoxime, airway management and ventilatory support
  • Sympathomimetic
    • Most Common Presentation
      • Mental Status – agitation
      • Heart – tachycardia, hypertension
      • Eyes – mydriasis
      • Skin – diaphoresis, hyperthermia
    • Other Common Problems
      • Mental Status – seizures
      • Neuromuscular – rhabdomyolysis
      • Heart – cardiac arrest, myocardial infarction
    • Agent – amphetamine, cocaine
    • Treatment – sedation, cooling, hydration
  • Hypoglycemic
    • Most Common Presentation
      • Mental Status – altered
      • Heart – tachycardia, hypertension
      • Skin – diaphoresis
    • Other Common Problems
      • Mental Status – abnormal behavior, slurred speech, seizures
      • Neuromuscular – paralysis
      • GI/GU – hypoglycemia
    • Agent – insulin, sulfonylureas
    • Treatment – glucose solutions intravenously or orally
  • Opioid
    • Most Common Presentation
      • Mental Status – depressed
      • Lung – respiratory depression
      • Eyes – miosis
    • Other Common Problems
      • Lung – edema
      • Skin – hypothermia
    • Agent – clonidine, heroin, morphine
    • Treatment – naloxone, respiratory support
  • Salicylates
    • Most Common Presentation
      • Mental Status – altered
      • Heart – tachycardia
      • Lung – hyperpnea, respiratory alkalosis
      • Skin – diaphoresis
      • GI/GU – nausea, emesis
      • Other – metabolic acidosis, tinnitus
    • Other Common Problems
      • Heart – cardiorespiratory arrest
      • Lung – edema
      • GI/GU – ketonuria
      • Other – fever (low grade)
    • Agent – aspirin, wintergreen oil
    • Treatment – hydration, urine alkalinization, hemodialysis
  • Serotonin
    • Most Common Presentation
      • Mental Status – altered especially agitation, hallucination
      • Neuromuscular – increased tone, hyperreflexia
      • Skin – hyperthermia
    • Other Common Problems
      • Mental Status
      • Neuromuscular – whole body tremors
    • Agent – SSRI, SSRI with other medications such as MAOI and TCAs, drugs of abuse including ectasy, LSD
    • Treatment – cooling, sedation, possibly cyproheptadine

Acetaminophen is not a toxidrome but a common poisoning so it included it here for comparison.

  • Acetaminophen
    • Most Common Presentation
      • Skin – diaphoresis
      • GI/GU – anorexia, nausea, emesis
    • Other Common Problems
      • Mental Status – altered, agitated
      • Heart – dysrhythmia
      • Skin – jaundice
      • GI/GU – hypoglycemia, hepatitis, pancreatitis, renal failure
    • Agent – acetaminophen
    • Treatment – N-acetyl choline

Questions for Further Discussion
1. What is the telephone number for the American Association of Poison Control Centers where 24 hour information can be obtained?
2. What substances are tested for in your local urine toxicology screening test?
3. What are indications for activated charcoal?
4. Under what circumstances is Syrup of Ipecac used?
5. What are some measures parents can take at home to prevent an accidental overdose?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Poisoning

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Fleisher GR, Ludwig S. Synopsis of Pediatric Emergency Medicine. Williams and Wilkins. Baltimore, MD. 1996:405-415.

RxList. Tegretol.
Available from the Internet at http://www.rxlist.com/tegretol-drug.htm (rev. 1/3/2008, cited 9/27/2010).

Waseem W, Gernsheimer JR. Toxicity, Carbemazepine. eMedicine.
Available from the Internet at http://emedicine.medscape.com/article/1011240-overview (rev. 10/27/2009, cited 9/27/2010).

Defendi GL, Tucker JR. Toxicity, Acetaminophen. eMedicine.
Available from the Internet at http://emedicine.medscape.com/article/1008683-overview (rev. 4/16/2010, cited 9/27/10).

Emergency Central. Table 98.1 Toxidromes.
Available from the Internet at http://emergency.unboundmedicine.com/emergency/ub/view/Emergency-Medicine-Manual/410204/0/Toxidromes (rev. 2010, cited 9/27/2010).

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Interpersonal and Communication Skills
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

  • Professionalism
    21. A commitment to ethical principles pertaining to provision or withholding of clinical care, confidentiality of patient information, informed consent, and business practices are demonstrated.


    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital