Recognition and Management of Acute Pesticide Poisoning
WILLIAM M. SIMPSON, JR., M.D., and STANLEY H. SCHUMAN, M.D.,
Medical University of South Carolina, Charleston, South Carolina
Most poisonings from pesticides do not have a specific
antidote, making decontamination the most important intervention. For
maximal benefit to the patient, skin, eye, and gastric decontamination
should be undertaken while specifics of the poisoning are being
determined. As in most illnesses and injuries, the history of the
poisoning is of great importance and will determine specific needs for
decontamination and therapy, if any exist. Protection of health care
workers during the decontamination process is important and frequently
overlooked. Skin decontamination is primarily accomplished with large
volumes of water, soap, and shampoo. Gastric decontamination by lavage is
indicated if ingestion of the poisoning has occurred within 60 minutes of
patient presentation. Activated charcoal, combined with a cathartic, is
also indicated in most poisonings presenting within 60 minutes of
ingestion. With large volume ingestion poisonings, activated charcoal may
be used after 60 minutes, but little data exist to support this practice.
Syrup of ipecac is no longer recommended for routine use. The cholinergic
syndrome "all faucets on" characterizes poisoning by organophosphates and
carbamates. Organochlorine insecticides (lindane and other treatments for
scabies and lice) can produce seizures with excessive use or use on large
areas of nonintact skin. Nondipyridyl herbicides, biocides (including
pyrethrins, pyrethroids, and Bacillus thuringiensis) rarely produce
anything other than mild skin, eye, and/or gastrointestinal irritation on
topical exposure or ingestion. (Am Fam Physician 2002;65:1599-604.
Copyright© 2002 American Academy of Family Physicians.)
Acute pesticide poisoning is an unusual
and potentially fatal reason for visiting a family physician in the outpatient
or emergency department setting. These episodes are likely to occur so
infrequently that the physician must go through a steep learning curve with each
encounter. However, a few items of history, knowledge of the small number of
specific antidotes, and access to a limited number of resources (including the
regional poison control center) will allow the physician to successfully
initiate management for pesticide poisonings and most other poisons and to avoid
mistakes from inexperience.
|Because one of the
potential measures of toxicity of an exposure is its duration, time
is of the essence in recognizing pesticide poisoning. |
Poisoning events involving pesticides account for about 4
percent of all poisonings and result in approximately 15 deaths per year, or
0.02 percent of all pesticide poisoning events reported.
Recognition of Poisoning
Sometimes pesticide poisoning is obvious. The patient is
brought in with a container of pesticide, the pesticide residue is still in the
patient's mouth, and the patient has symptoms that are characteristic of the
labeled pesticide. Often, this ideal scenario does not exist. The exposure may
be uncertain, the pesticide found with the patient may or may not be the
ingested poison, and the patient may exhibit no symptoms or symptoms
uncharacteristic of the presumed exposure. Because one of the potential measures
of toxicity of an exposure is its duration, time is of the essence.
Decontamination must be undertaken while questions about the
specific exposure are answered and supportive or specific therapy is being
Respiratory and skin protection is required for health care
workers involved with treating patients that have been poisoned. Latex gloves
are inadequate for protection from many chemicals; only rubber gloves are
appropriate for use in a poisoning situation. A full face mask with an organic
vapor/high efficiency particulate air filter should be used until skin and
gastrointestinal decontaminations are completed.
|Latex gloves are
inadequate for protection from many chemicals; only rubber gloves
are appropriate for use in a poisoning situation. |
Skin decontamination is accomplished with a shower using
soap, large amounts of water, and shampoo. Skin folds, areas underneath
fingernails, ear canals, and other portions of the body that may trap chemicals
should be inspected and cleaned carefully. Contact lenses should be removed, so
the eyes can be inspected and irrigated thoroughly if exposure is suspected.
Contaminated clothing should be removed, bagged, and laundered carefully.
Leather items usually cannot be decontaminated and should be bagged and treated
as hazardous waste.
Gastrointestinal decontamination may be accomplished in
several ways, each having specific indications and contraindications. The
American Academy of Clinical Toxicology (AACT) and the European Association of
Poisons Centres and Clinical Toxicologists (EAPCCT) have recently produced a
position statement1 on these therapies. A summary is included in the
discussion of each potential therapy (Table 1). These therapies
are also discussed in greater detail in the fifth edition of Recognition and Management of Pesticide Poisonings.2
While skin and gastrointestinal decontamination are
progressing, investigation into the background of the exposure should be
ongoing. Family members, co-workers, and emergency response personnel should be
interviewed to determine how the exposure occurred--inhalation, ingestion, skin
contact, or combination (Is the environment safe now? Can others be protected
from future exposure to poisoning risk?); if anyone else was exposed (Have all
who were exposed been evaluated?); if there are other potential poisons involved
(Are there symptoms that do not fit the presumed poison?); and if a specific
antidote to the presumed poison exists (Has it been obtained and is it ready for
Methods of Gastrointestinal
- Gastric lavage
- Consider if patient presents within 60 minutes of ingestion.
- Insert orogastric tube.
- Attempt aspiration first, followed by 100 to 200 mL normal
saline, then aspiration.
- Relatively contraindicated in hydrocarbon ingestion
- Neurologically impaired: cuffed endotracheal tube prior to
- AATC/EAPCCT Position Statement: gastric lavage not routinely
used in poisonings. It is indicated only when potentially
life-threatening amount of poison is ingested and the procedure
can be done within 60 minutes of ingestion.
- Used only in combination with activated charcoal
- Sorbitol (1 to 2 mL/kg or 70 percent solution in adults, 1.5
to 2.5 mL/kg of 35 percent solution in children)
- Single dose only
- Not recommended in poisonings that produce diarrhea
(organophosphates, carbamates, heavy metals in particular) or
those that produce ileus (paraquat and diquat)
- AATC/EAPCCT Position Statement: Cathartic alone has no place
in management of poisoned patient. No definite indications for use
of cathartics and its routine use with activated charcoal is not
endorsed. If it is used, it should be as a single dose. Numerous
contraindications: absent bowel sounds, abdominal trauma or
surgery, intestinal perforation or obstruction, volume depletion,
hypotension, or ingestion of a corrosive substance.
- Activated charcoal
- Used in conjunction with a cathartic if patient presents
within 60 minutes of ingestion. (Some authorities would use beyond
60 minutes if serious poisoning is suspected.)
- Dose: Adults and children >12 years, 25 to 100 g in 300 to
800 mL water; children <12 years, 1 gm/kg in 300 mL water
- Dose may be repeated in 2 to 4 hours if bowel sounds are
- Antiemetic suppository for nausea
- Administered by nasogastric tube if unable to tolerate or
unable to swallow
- Protect airway if hydrocarbon-containing pesticide or unknown
- AATC/EAPCCT Position Statement: Activated charcoal should not
be used routinely in management of poisoned patients. Charcoal
appears to be most effective within 60 minutes of ingestion and
may be considered for use for this time period. There is
insufficient evidence to support or deny its use beyond 60 minutes
- Syrup of ipecac
- No longer indicated for routine use
- Dose: adults and children >12 years, 15 to 30 mL followed
by 240 mL water; children <12 years, 15 mL preceded or followed
by 120 to 240 mL water; infants six to 12 months of age, 5 to 10
mL preceded or followed by 120 to 240 mL water
- Dose may be repeated in all age groups if emesis does not
occur within 20 to 30 minutes.
- Contraindicated in patients with diminished airway protective
reflexes, ingestion of hydrocarbons with aspiration potential,
ingestion of a corrosive substance, or ingestion of a substance
for which advanced life support may be necessary within the next
- AATC/EAPCCT Position Statement: Ipecac syrup should not be
administered routinely in poisoned patients. If it is used, it
should be administered within 60 minutes of ingestion. Considered
only in alert patients who have ingested a potentially serious
toxin. Same contraindications as listed above.
AATC/EAPCCT = American Academy of Clinical
Toxicology/European Association of Poisons Centres and Clinical
Information from American Academy of Clinical
Toxicology, European Association of Poisons Centres and Clinical
Toxicologist. Position statements. J Toxicol Clin Toxicol 1997;35,
and Reigart JR, Roberts JR. Recognition and management of pesticide
poisoning. 5th ed. U.S. Environmental Protection Agency, Washington,
The label on the container of the pesticide involved is an
invaluable resource for proper poisoning management. The Environmental
Protection Agency requires a labeled statement of practical poisoning management
and a telephone number for additional information. If the label is illegible or
legible but more than a few years old, the regional poison control center should
be able to provide up-to-date information on acute poisoning management.
With an unknown pesticide exposure, a land grant college
Cooperative Extension Service agent who is familiar with local pesticide
practices may be able to provide information about the most likely agrochemical
in use in that area at a particular time of the year, on a particular crop, or
in a specific environment.
The Extension Toxicology Network (EXTOXNET) is available at
www.ace.orst.edu/info/ extoxnet. The National Pesticide Information Center is
available 9:30 a.m. to 7:30 p.m. EST at 800-858-7378 and at www.npic.orst.edu/
index.html/. The American Association of Poison Control Centers (AAPCC) has
recently established a national poison control hotline number (800-222-1222)
that connects callers to the nearest poison control center. The AAPCC Web
address is www.1-800- 222-1222.info/poisonHelp.asp.
The most common sources of pesticide poisonings, signs and
symptoms, and specifics of management are addressed in Table
Most Common Pesticide Poisonings:
Recognition and Management
Mechanism of action/toxicity
- Acephate (Orthene)
- Chlorphoxim (Baythion-C)
- Chlorpyrifos (Dursban, Lorsban)
- Dimethoate (Cygon, DeFend)
- Ethoprop (Mocap)
- Fenitrothion (Sumithion)
- Fenthion (Baytex)
- Malathion (Cythion)
- Naled (Dibrome)
- Terbufos (Counter)
leading to excess acetylcholine
skeletal nerve-muscle junctions, autonomic ganglia--twitching,
tachycardia, muscle weakness (nicotinic effects); peripheral
cholinergicneuroeffector junctions--"all faucets
on"--sweating, salivation, diarrhea, tearing (muscarinic
effects); miosis (pinpoint pupils) most commonly, but 15
percent have mydriasis secondary to epinephrine release from
adrenals due to nicotinic receptor stimulation.
- Draw red cell cholinesterase and plasma
pseudocholinesterase levels before therapy. Do not delay
treatment while awaiting results.
- Maintain and protect airway.
- Supplemental oxygen
- Atropine (preservative-free, if possible), 2 to 5 mg IV
every 15 minutes (adults and children >12 years) until
pulmonary symptoms controlled; children < 12 years, 0.05
to 0.1 mg/kg every 15 minutes; doses repeated as needed for
symptom control (up to 24 hours, taper dose)
- Pralidoxime (2-PAM, Protopam) IV, 1 to 2 g(adults) over
10 minutes, 20 to 50 mg/kg (<12 years) over 30 minutes;
repeated in 1 to2 hours and at 10- to 12-hour intervals as
needed for symptom control; alternatively: continuous IV
infusion 10 to 20 mg/kg/hr(up to 500 mg/hr) after initial
bolus and continued for 24 hours
- Furosemide (Lasix), 40 to 160 mg IV for pulmonary
congestion remaining after full atropinization
- Benzodiazepine for seizures (diazepam [Valium]), 5 to 10
mg slow IV push, repeated every 5 to 10 minutes to control
or maximum 30 mg in adults; 0.2 to 0.5 mg/kg IV every 5
minutes to maximum of 10 mg in children >5 years, 5 mg in
children <5 years; lorazepam may also be used
- Carbaryl (Sevin)
- Pirimicarb (Aphox, Rapid)
- Propoxur (Baygon)
- Timethacarb (Landrin)
- Other carbamates
(carbamoyl-acetylcholinesterase[AChE] complex dissociates much
more easily and quickly than OP-AChE complex)
||Cholinergic crisis with "all faucets on"; CNS
depression with coma, seizures, hypotonicity in serious toxic
- Maintain and protect airway.
- Optimize oxygenation/supplemental oxygen.
- Atropine IV (preferably or IM) Adults, children >12
years, 2.0 to 4.0 mg every 15 minutes until secretions
controlled; children <12 years, 0.05 to 0.10 mg/kg every
15 minutes untilsecretions controlled; continue 2 to 12
hours; continued signs of poisoning indicate need for more
- Furosemide (Lasix), 40 to 160 mg, if basilar rales
persist after atropinization
- Pralidoxime not indicated in pure carbamate poisoning;
may be necessary in mixed organophosphate/carbamate
poisoning or unknown poisoning with cholinergic syndrome.
- Dicofol (Kelthane)
- Dienochlor (Pentac)
- Lindane (Kwell)
hyperexcitable state in central and peripheral nervous system
by disruption of normal flow of sodium and potassium across
the axon membrane; may antagonize GABA-mediated inhibition in
dizziness, nausea, vomiting, paresthesias, incoordination,
tremor/twitching following topical treatment for lice/scabies
or accidental or intentional ingestionof liquid pesticide
- Maintain and protect airway.
- Ensure adequate oxygenation.
- Seizure control with diazepam; adults, 5 to 10 mg IV
push over 2 to 5 minutes, repeated every 10 minutes as
necessary; children, <12 years 0.04 to 0.2 mg/kg every 10
minutes, monitoring airway closely; lorazepam may be used as
- IV fluids with dextrose (5 to 10 percent) and thiamine
100 to 500 ng/L
- Dysrhythmias from rare myocardial irritant effect
treated with lidocaine (1 mg/kg bolus, 2 to 4 mg/minute
- Cyfluthrin (Baythroid)
- Cypermethrin (Barricade, Cymbush, Cynoff, Demon)
- Permethrin (Ambush, Dragnet, Nix, Pounce)
|Pyrethrins are derived from chrysanthemums;
pyrethroids are synthetic compounds with longer half-lives;
both can produce toxic effects on the nervous system but are
not well absorbed and are effectively and quickly detoxified
by mammalian liver enzyme systems.
severe symptoms are seizures, though highly uncommon unless
highly exposed (usually through ingestion of large
quantities); tremor, incoordination, salivation, vomiting;
topical exposure can produce short-term paresthesias,
especially of the hands and face; a small portion of the
population (1 to 3 percent) is allergic to
pyrethrins/pyrethroids--resulting in symptoms ranging from
nasal stuffiness to asthma.
- Skin decontamination by thorough washing with soap and
water is suggested; vitamin E oil preparations are effective
in preventing and treating paresthesias; corn oil and
petrolatum are less effective.
- Seizures controlled with benzodiazepines.
- Standard antiallergy therapy for hypersensitivity
- Bacillus thuringiensis
- Variety aizawai (Agree, Mattch)
- Variety israelensis (Aquabac, Skeetal)
- Variety kurstaki (Bactur, Dipel)
Wide range of
productsderived from several varieties of this organism;
highly limited effects onmammalian systems
pulmonary symptoms in some involved in manufacturing process,
not in mixers or appliers; theoretical risk of respiratory
infection in immunocompromised individuals; single corneal
ulceration reported, successfully treated with standard
antibiotics; mild gastroenteritis with heavyingestion
- Symptomatic treatment following decontamination
- Diethyltoluamide-- DEET (Muskol, Off!, Skeeter Beater,
Skeeter Cheater, Skintastic for Kids, others)
|Mechanism of toxicity unknown
depression followed by seizures; rare unless applied
excessively under occlusion; mild skin irritating effects with
repeated use; corneal and mucosal irritation; nausea and
vomiting with ingestionand, rarely, hypotension, tachycardia
with heavy dermal exposure
- Control of seizures with benzodiazepines
- Supportive care
CNS = central nervous system; IV = intravenous; IM =
intramuscular; GABA = gamma-aminobutyric acid.
Information from references 1 through 5.
Miscellaneous Solvents and Adjuvants
The liquid materials in which pesticides are dissolved and
the solids on which they are adsorbed are chosen by the manufacturers to achieve
ease in handling and application, and stability and maximal effectiveness of the
active ingredient. The most commonly used solvents are petroleum distillates.
Often, the odor that lingers after a pesticide application is that of the
petroleum distillate rather than that of the active ingredient. Petroleum
distillates may produce toxicities in themselves in large volume ingestions.
Most adjuvants (emulsifiers, penetrants, and safeners) are potential skin and
eye irritants of very low toxicity. Treatment of exposure is with
decontamination by dilution with water.
|The label on the container
of the pesticide involved is an invaluable resource for proper
poisoning management. |
With increasing use of integrated pest management and lower
toxicity pesticides, acute pesticide poisoning will likely continue to be an
infrequent reason for visiting a physician in the outpatient and emergency
department settings. Because most of the commonly used pesticides have no
specific antidote, decontamination of the skin, hair, eyes, and gastrointestinal
tract is the primary mode of intervention. Recognition of the cholinergic
syndrome associated with organophosphate and carbamate exposure allows for
specific treatment of this increasingly rare event. Some members of other
pesticide classes also have specific antidotes, making identification of the
chemical necessary for optimal therapy. This emphasizes the need for teamwork
with the patient, family, employer/supervisor, or Cooperative Extension Service
Accidental pesticide exposures invite consideration of
educational interventions to prevent recurrences, whether they be on an
individual, family, community, or industry-wide scale. Because up to one half of
pesticide poisonings are intentional in some age groups, particularly teenagers,
the family physician must use the event as a trigger for screening for
depression or other psychiatric illnesses.
The authors indicate that they do not have any conflicts of
interest. Sources of funding: none reported.
Members of various family practice departments develop articles
for "Practical Therapeutics." This article is one in a series coordinated by the
Department of Family Medicine at the Medical University of South Carolina,
Charleston. Guest editor of the series is William J. Hueston, M.D.
WILLIAM M. SIMPSON, JR., M.D., is a professor in the department of
family medicine at the Medical University of South Carolina, Charleston. Dr.
Simpson received his medical degree from the Medical University of South
Carolina and completed a family practice residency there.
STANLEY H. SCHUMAN, M.D., DrPH, is a professor in the departments
of family medicine and pediatrics at the Medical University of South Carolina.
Dr. Schuman received his medical degree from Washington University, St. Louis,
and his doctorate in public health from the University of Michigan, Ann Arbor.
Address correspondence to William M. Simpson, Jr., M.D.,
Department of Family Medicine, Medical University of South Carolina, P.O. Box
250805, Charleston, S.C. 29425-0805 (e-mail: email@example.com). Reprints are available
from the authors.
- American Academy of Clinical Toxicology, European Association of Poisons
Centres and Clinical Toxicologists. Position statements. J Toxicol Clin
Toxicol 1997;35:699-709,711-19,721-41,743-52, 753-62.
- Reigart JR, Roberts JR. Recognition and management of pesticide
poisonings. 5th ed. U.S. Environmental Protection Agency, Washington, D.C.,
- Gallo MA, Lawryk NJ. Organic phosphorus pesticides. In: Hayes WJ, Laws ER
(eds). Handbook of pesticide toxicology. San Diego: Academic Press,
- Carlton FB, Simpson WM, Haddad LM. The organophosphates and other
insecticides. In: Haddad LM, Shannon MW, Winchester JF (eds). Clinical
management of poisoning and drug overdose. 3d ed. Philadelphia: Saunders,
- Tucker SB, Flannigan SA, Ross CE. Inhibition of cutaneous paresthesia
resulting from synthetic pyrethroid exposure. Int J Dermatol 1984;10:686-9.
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