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DESCRIPTION
The organochlorine pesticides are chlorinated hydrocarbons usually in a petroleum distillate solvent base.
FORMS AND USES
- The organochlorines are composed of several subgroups.
- Dichlorodiphenylethanes. DDT (dichlorodiphenyltrichloroethane), DDD, DDE, dicofol, dienochlor, and methoxychlor.
- Hexachlorocyclohexanes. Hexachlorocyclohexane and lindane.
- Cyclodienes. Aldrin, dieldrin, chlordane, endrin, endosulfan, ethylan, heptachlor, and toxaphene.
- Others. Chlordecone, mirex, orthodichlorobenzene, hexachlorobenzene, strobane, kelthane, perthane, chloropyrolate, and chlorobenzilate.
- Once the most common insecticides, they are largely banned in the United States.
- Lindane is still used for treatment of scabies.
TOXIC DOSE
- Any ingestion of 100% lindane is likely to produce toxicity.
- A lindane ingestion of less than 1 teaspoon in a child or less than 1 tablespoon in an adult is considered nontoxic.
- Toxicity may follow ingestion, skin application, or inhalation.
PATHOPHYSIOLOGY
- Organochlorines interfere with the transmission of nerve impulses by altering neuronal ion flux.
- Exposure may result in either impairment of function (respiratory depression) or enhanced activity (seizures).
- Some evidence suggests that lindane may antagonize gamma-aminobutyric acid (GABA)-mediated inhibition in the CNS.
- Carcinogenesis. None of the organochlorines are known human carcinogens.
EPIDEMIOLOGY
- Poisoning is uncommon.
- Toxic effects are typically mild to moderate, but may be severe with large exposure.
- Death occurs with massive exposure.
CAUSES
- Exposure is usually accidental or inadvertent misuse of product; intentional ingestion usually involves larger quantities.
- Child abuse/neglect must be considered if the patient is less than 1 year of age; suicide attempt if the patient is over 6 years of age.
DRUG AND DISEASE INTERACTIONS
Stimulants or other drugs that induce seizure may increase the risk of seizure from organochlorine compounds.
PREGNANCY AND LACTATION
- Lindane. US FDA Pregnancy Category B. Animal studies indicate no fetal risk and there are no controlled human studies, or animal studies show an adverse fetal effect but well-controlled studies in pregnant women do not.
- Organochlorines cross into breast milk; acute toxic effects have not been reported.
WORKPLACE STANDARDS
Aldrin and Dieldrin
- ACGIH. TLV TWA is 0.25 mg/m3.
- OSHA. PEL TWA is 0.25 mg/m3.
- Carcinogen status. IARC 3; EPA B2.
Chlordane and Heptachlor
- ACGIH. TLV TWA is 0.5 mg/m3.
- OSHA. PEL TWA is 0.5 mg/m3.
- Carcinogen status. IARC 2B; EPA B2.
DDT
- ACGIH. TLV TWA is 1 mg/m3.
- OSHA. PEL TWA is 1 mg/m3.
- Carcinogen status. IARC 2B; EPA B2.
Endosulfan
- ACGIH. TLV TWA is 0.1 mg/m3,
- Carcinogen status. TLV is A4.
Endrin
- ACGIH. TLV TWA is 0.1 mg/m3.
- OSHA. PEL TWA is 0.1 mg/m3.
- Carcinogen status. IARC 3; EPA D.
Lindane
- ACGIH. TLV TWA is 0.5 mg/m3.
- OSHA. PEL TWA is 0.5 mg/m3.
- Carcinogen status. IARC 2B; TLV A3.
Methoxychlor
- ACGIH. TLV TWA is 10 mg/m3.
- OSHA. PEL TWA is 15 mg/m3.
- Carcinogen status. IARC 3; EPA D.
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DIFFERENTIAL DIAGNOSIS
- Toxic causes of agitation and seizures include sympathomimetic drugs, theophylline, lithium, monoamine oxidase inhibitors, isoniazid, and alcohol or sedative withdrawal, among others.
- Nontoxic causes include noncompliance with seizure medications, and CNS infection or injury.
SIGNS AND SYMPTOMS
CNS excitation and seizures are the principal concerns.
Vital Signs
Hypertension, tachycardia, and bradypnea may occur.
Dermatologic
Dermatitis may be present at areas of prolonged contact.
Cardiovascular
Hydrocarbons may predispose to dysrhythmia.
Pulmonary
Aspiration pneumonitis may develop from a petroleum distillate component following ingestion.
Gastrointestinal
- Nausea and vomiting are common.
- The petroleum distillates may cause diarrhea.
Hepatic
No human hepatotoxicity has been demonstrated.
Renal
Renal failure from rhabdomyolysis may follow prolonged seizure activity.
Hematologic
Porphyria cutanea tarda (hexachlorobenzene) and megaloblastic anemia (chlordane) are rare effects.
Neurologic
- Seizures are common with large ingestions or prolonged skin contact of some compounds (aldrin, chlordane, dieldrin, endrin, heptachlor, lindane, strobane, toxaphene, and DDT).
- CNS depression predominates in others (kelthane, perthane, methoxychlor, hexachlorobenzene).
- CNS irritation, agitation, amnesia, and opsoclonus (chlordecone) have been reported.
PROCEDURES AND LABORATORY TESTS
Essential Tests
No tests may be needed in asymptomatic patients or following minor inhalational exposure.
Recommended Tests
- Serum electrolytes, BUN, creatinine, glucose, calcium, and magnesium are measured if repeated vomiting or seizure develops.
- Complete blood count (CBC) in severe or chronic exposure is used to detect blood dyscrasia.
- CT, lumbar puncture, cultures, pulse oximetry, and other tests are used as needed to assess altered mental status.
- ECG, serum acetaminophen and aspirin levels are used in an overdose setting to assess occult ingestion.
- Specific levels are available as send-out test only and may be used for confirmation of exposure (e.g., lindane level).
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- Treatment should focus on airway support and control of seizures.
- Dose and time of exposure should be determined for all substances that could be involved.
DIRECTING PATIENT COURSE
The health-care provider should call the poison control center when:
- Seizure, altered mental status, or other serious effects are present.
- Toxic effects are not consistent with organochlorine poisoning.
- Coingestant, drug interaction, or underlying disease presents an unusual challenge.
The patient should be referred to a health-care facility when:
- Attempted suicide or homicide is possible.
- Patient or caregiver seems unreliable.
- Any toxic effects develop.
- Coingestant, drug interaction, or underlying disease presents unusual problems.
Admission Considerations
Inpatient management is warranted if patient experiences seizures or other major toxicity.
DECONTAMINATION
Out of Hospital
Skin
The affected area should be washed with soap and water thoroughly, and patient's clothing should be discarded in a hazardous materials bag.
Ingestion
Emesis should not be induced due to the risk of seizures.
Inhalation
Patient should be moved to fresh air.
In Hospital
Skin
- The affected area should be washed with soap and water repeatedly, and the patient's clothing should be discarded in a hazardous materials bag.
Ingestion
- Gastric lavage should be performed in pediatric (tube size 24-32 French) or adult (tube size 36-42 French) patients presenting within 1 hour of a large ingestion or if serious effects are present.
- One dose of activated charcoal (1-2 g/kg) should be administered without a cathartic if a substantial ingestion has occurred within the previous few hours.
ANTIDOTES
There is no specific antidote for organochlorine poisoning.
ADJUNCTIVE TREATMENT
Seizure management includes the following measures:
- Adequate airway and oxygenation are crucial.
- Benzodiazepine should be administered for initial control.
- Diazepam. Adult dosage is 5 to 10 mg intravenous push over 2 to 5 minutes initially, repeated every 10 minutes as needed; pediatric dosage is 0.2 to 0.5 mg/kg every 10 minutes as needed; airway must be monitored closely.
- Lorazepam. Adult dosage is 2 to 4 mg intravenous push over 2 to 5 minutes, repeated every 10 minutes as needed; pediatric dosage is 0.1 mg/kg intravenous push over 2 to 5 minutes, not to exceed 4 mg/dose, repeated every 10 minutes as needed; airway must be monitored closely.
- If seizures persist or recur, another anticonvulsant such as phenobarbital or phenytoin may be added.
- Other options for repeated seizures include general anesthesia and neuromuscular blockade with EEG monitoring.
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PATIENT MONITORING
- Respiratory and hemodynamic status should be monitored continuously until acute effects resolve.
- CBC should be monitored in patients with chronic exposure.
EXPECTED COURSE AND PROGNOSIS
- Following ingestion, most patients become acutely ill and improve with supportive care over the next 24 to 48 hours.
- Severe cases may require several days to recover.
- Sequelae of repeated seizure activity (rhabdomyolysis, acidosis, long-term CNS injury) may develop rarely.
DISCHARGE CRITERIA/INSTRUCTIONS
- From the emergency department. Asymptomatic patients can be discharged following decontamination, observation for 6 hours, and psychiatric evaluation, if needed.
- From the hospital. Patients can be discharged following resolution of toxic effects and psychiatric evaluation, if needed.
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DIAGNOSIS
Failure to consider organochlorine pesticides in the differential diagnosis of seizures can lead to misdiagnosis.
TREATMENT
- Failure to adequately control airway and seizures is a common pitfall.
- Multiple drug therapy may be required for adequate seizure control.
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ICD-9-CM 989Toxic effect of other substances, chiefly nonmedicinal as to source.
See Also: SECTION II, Seizures chapter.
RECOMMENDED READING
Peters HH, Gocmen A, Cripps DJ, et al. Epidemiology of hexachlorobenzene-induced porphyria in Turkey: clinical and laboratory follow-up after 25 years. Arch Neurol 1982;39:744-749.
Rowley DL, Rab MA, Hardjotanojo W, et al. Convulsions caused by endrin poisoning in Pakistan. Pediatrics 1987;79:928-934.
Samuels AJ, Milby TH. Human exposure to lindane: clinical hematological and biochemical effects. J Occup Med 1971;13:147-151.
Author: Scott D. Phillips
Reviewer: Luke Yip