Pesticides Pesticides Stimulants and street drugs

Plants Antiepileptic agents Muscle relaxants

GI products Personal care products Cyclic antidepressants

Antimicrobials Antihistamines Antiepileptic agents

Arts and office supplies Hormones and hormone antagonists Fumes/gases/vapors

Alcohols Antimicrobials Aspirin

Hormones and hormone

antagonists

Chemicals Nonsteroidal anti-inflammatory drugs

Cardiovascular agents Fumes/gases/vapors Antihistamines

Hydrocarbons

a

Poisoning exposures are listed in order of frequency encountered.

GI, gastrointestinal.

Source: Bronstein AC et al. 2009 Annual report of the American Association of Poison Control Centers’ National Poison Data

System (NPDS): 27th Annual Report. Clin Toxicol (Phila). 2010;48:979.

managed at home.3 Severe toxicity in young children is relatively

uncommon as exposures usually involve the ingestion of relatively small amounts of a single substance.6,7 Of pediatric cases

reported to AAPCC, there were 769 (0.06%) life-threatening outcomes and 31 (0.00%) fatalities from a total of 1,290,784 pediatric

cases.3

AAPCC epidemiologic data also report medication errors,

which in the pediatric population commonly result from confusing units of measurement (e.g., teaspoons vs. milliliters or tablespoons vs. teaspoons), incorrect formulation or concentration

administered, dispensing cup errors, and incorrect formulation

or concentration dispensed from the pharmacy.3

In children older than 6 years of age, the reasons for toxic

exposure to medications are less clear.8 Adolescent children generally have poor knowledge of the toxicity of medications and

can overdose themselves unintentionally.6,9 The potential for

suicide attempts or intentional substance abuse should not be

ignored in older children. These intentional overdoses commonly

involve mixed exposures to illicit drugs, prescribed medications,

or ethanol, and are associated with more severe toxicity and death

than unintentional toxic exposures.

For many teens, using prescription drugs is not considered

dangerous as the drugs are not illegal like heroin or cocaine. In

a 2007 survey, 9.5% of adolescents 12 to 17 years of age said they

had used an illicit substance in the past month.10 The lifetime

use of opiates or opioids, other than heroin, in 12th graders has

doubled from 6.6% in 1991 to 13.2% in 2008.10

In geriatric patients, overdoses tend to have a greater potential

for severe adverse effects compared with overdoses in other age

groups.11 Although the elderly constitute 13% of the population,

they account for 33% of the drug use and 16% of the suicides.12

Patients age 65 or older take an average of 5.7 prescription medications along with 2 to 4 nonprescription drugs daily.11,12 In

2007, the suicide rate for people 65 years and older was 14.3 per

100,000 population compared with the national average of

11.3 per 100,000.13 The elderly are more likely to have underlying illnesses and often have access to a variety of potentially

dangerous medications. This results in higher rates of completed

suicides than in other age groups.11,12

68 Section 1 General Care

Information Resources

COMPUTERIZED DATABASES

A vast number of substances can be involved in a poisoning or

overdose. Reliable data about the contents of products, toxicities of substances, and treatment approaches need to be readily accessible. POISINDEX, a computerized database,14 provides

information on thousands of drugs by brand name, generic name,

and street name, as well as foreign drugs, chemicals, pesticides,

household products, personal care items, cleaning products, poisonous insects, poisonous snakes, and poisonous plants. Annual

subscriptions to POISINDEX, updated quarterly, are expensive

and are generally available only in large medical centers.15

PRINTED PUBLICATIONS

Textbooks and manuals also provide useful clinical information

about the presentation, assessment, and treatment of toxicities.

Goldfrank’s Toxicologic Emergencies16 and the pocket-size Poisoning & Drug Overdose17 are valuable, less-expensive alternatives to

computerized database programs. Books, however, are less useful than computerized databases because information must be

condensed and cannot be updated as frequently. Some drug package inserts also refer to treatment of acute toxicities; however,

the information can be inadequate or inappropriate.18,19

POISON CONTROL CENTERS

Poison control centers provide the most cost-effective and accurate information to health care providers and to the general

public.20,21 Poison centers are staffed by trained poison information specialists who have a pharmacy, nursing, or medical

background. Physician backup is provided 24 hours a day by

board-certified medical toxicologists. The nonphysician clinical

toxicologists, pharmacists, and nurses who staff poison control

centers are certified as specialists in poison information by the

AAPCC or as clinical toxicologists by the American Board of

Applied Toxicology.22

The poison information specialist must accurately and efficiently assess event-specific toxicity by telephone, without the

benefit of direct observation of the patient. The specialist must

communicate this assessment along with treatment information

quickly, accurately, and professionally in a reassuring manner.

Subsequent to telephone consultations, poison control center

staff should initiate follow-up calls to determine the effectiveness of the recommended treatment and the need for additional

evaluation or treatment.23,24

EFFECTIVE COMMUNICATION

Effective communication is essential to the assessment of potential poisonings. In most situations, the person seeking guidance

on the management of a potentially toxic exposure is the parent

of a small child who may have ingested a substance. The caller

is usually anxious about the child and may feel guilty about the

exposure. To calm the caller, the health care provider should

quickly reassure the parent that telephoning for help was appropriate and that the best assistance possible will be provided.24

If English is not the first language of the caller, or if there are

other communication barriers (e.g., panic), solutions must be

found to enhance outcomes. Most poison centers subscribe to

translation services or have bilingual staff to communicate with

non–English-speaking callers. Poison centers also have special

equipment to serve the hearing- and speech-impaired populations.

Once calm, effective communication is established, the health

care provider should first determine whether the patient is conscious and breathing and has a pulse. If life-threatening symptoms have occurred, the caller should call 9-1-1 for emergency

services. If the health care provider does not have the knowledge

or resources to provide poison information, he or she should

refer the caller to the closest poison control center. Information

on the location and phone number of the nearest poison control center can be found at http://www.aapcc.org or by calling

1-800-222-1222 in the United States.

GENERAL MANAGEMENT

Supportive Care and “ABCs”

Management of poisoned or overdosed patients is primarily based

on symptomatic and supportive care. Specific antidotes exist only

for a small percentage of the thousands of potential drugs and

chemicals that can cause a poisoning.

The first aspect of patient management should always be basic

support of airway, breathing, and circulation (the “ABCs”). The

assessment and treatment of the potentially poisoned patient

can be separated into seven primary functions: (a) gathering

history of exposure, (b) evaluating clinical presentation (i.e.,

“toxidromes”), (c) evaluating clinical laboratory patient data,

(d) removing the toxic source (e.g., irrigating eyes, decontaminating exposed skin), (e) considering antidotes and specific treatment, (f ) enhancing systemic clearance, and (g) monitoring

outcome.25–27

GATHERING HISTORY OF EXPOSURE

Comprehensive historical information about the toxic exposure

should be gathered from as many different sources as possible

(e.g., patient, family, friends, prehospital health care providers).

This information should be compared for consistency and evaluated relative to clinical findings and laboratory results. The

patient’s history of the exposure is often inaccurate and should be

confirmed with objective findings.25,26,28 For example, a patient

who presents to an ED with a supposed hydrocodone and carisoprodol overdose is expected to be lethargic or comatose. If the

patient arrives wide awake with tachycardia and agitation, the

caregiver should suspect exposure to other substances.

Specific information should be sought concerning the

patient’s state of consciousness, symptoms, probable intoxicant(s), and maximal amount and dosage form(s) of substance

ingested, as well as when the exposure occurred. Medications,

allergies, and prior medical problems also should be ascertained

to facilitate development of treatment plans (e.g., a history of

renal failure may indicate the need for hemodialysis to compensate for decreased renal drug clearance).25,26

EVALUATING CLINICAL PRESENTATION

AND TOXIDROMES

A thorough physical examination is needed to characterize the

signs and symptoms of overdose, and should be conducted serially to determine the evolution or resolution of the patient’s

intoxication. An evaluation of the presenting signs and symptoms can provide clues to the drug class causing the toxicity, confirm the historical data surrounding the toxic exposure, and suggest initial treatment.25,29–31 The patient may be asymptomatic

on presentation, even though a potentially severe exposure has

occurred, if absorption of the drug or toxic substance is incomplete or if the substance has not yet been metabolized to a toxic

substance.32–34

Characteristic toxidromes (i.e., a constellation of signs and

symptoms consistent with a syndrome) can be associated

with some specific classes of drugs.26,30,31 The most common

toxidromes are those associated with anticholinergic activity,

increased sympathetic activity, and central nervous system (CNS)

69Managing Drug Overdoses and Poisonings Chapter 4

stimulation or depression. Anticholinergic drugs can increase

heart rate and body temperature, decrease gastrointestinal (GI)

motility, dilate pupils, and produce drowsiness or delirium. Sympathomimetic drugs can increase CNS activity, heart rate, body

temperature, and blood pressure (BP). Opioids, sedatives, hypnotics, and antidepressants can depress the CNS, but the specific

class of CNS depressant often cannot be easily identified.

Classic findings may not be present for all drugs within a therapeutic class. For example, opioids generally induce miosis, but

meperidine can produce mydriasis. Furthermore, the association

of symptoms with a particular class of toxic substances is difficult

when more than one substance has been ingested.