DESCRIPTION

Nicotine is derived from alkaloid plants of Nicotiana species such as wild tobacco, tree tobacco, and desert tobacco.

FORMS AND USES

• Nicotine is found in cigarettes, cigars, snuff, and chewing tobacco.
• Nicotine is used in insecticides, in veterinary applications as an ectoparasiticide, and in the leather tanning process.
• Nicotine gum (Nicorette) is used for smoking cessation and comes in 2- and 4-mg doses.
• Nicotine transdermal systems (Nicoderm, Nicotrol, Habitrol, Prostep) come in doses of 5 to 22 mg, used at intervals of 16 to 24 hours.
• Nicotine nasal spray (Nicotrol) comes as a 0.5- to 1.0-mg per metered dose spray at intervals of 30 minutes to 1 hour.
• Nicotine inhaler (Nicotrol) contains 10 mg per cartridge.

PATHOPHYSIOLOGY

• Initial stimulation of nicotinic receptors in the sympathetic and parasympathetic ganglia and neuromuscular junctions produces mild to moderate toxicity and is manifested by the classic symptoms of cholinergic excess.
• In severe toxicity, the initial stimulatory effect is followed by depolarization blockade of autonomic ganglion and neuromuscular transmission, which leads to muscle fasciculations and skeletal muscle paralysis.

TOXIC DOSE

• In a child, ingestion of one cigarette, three to five cigarette butts, a pinch of snuff, or any amount of gum, spray, or transdermal system may be toxic.
• In an adult, a lethal oral dose is estimated as more than 40 mg.

EPIDEMIOLOGY

• Poisoning is common.
• Toxic effects are typically mild to moderate.
• Severe toxicity is rare, with death occurring only after large ingestion, usually in a child who deteriorates before medical care is provided.
• Patients at the extremes of age are more susceptible to the effects of nicotine.

CAUSES

• Poisoning is usually accidental in children under 6 years of age.
• Child neglect or abuse should be considered if the patient is under 1 year of age; attempted suicide should be considered in patients over 6 years of age.

PREGNANCY

• US FDA Pregnancy Category D. Evidence of human fetal risk exists, but benefits in certain situations (e.g., life-threatening situations or serious diseases) may make use of the drug acceptable despite its risks.
• Nicotine may be a human teratogen.

WORKPLACE STANDARDS

• ACGIH. TLV TWA is 0.5 mg/m³
• OSHA. PEL TWA is 0.5 mg/m³.
• NIOSH. IDLH value is 5 mg/m³.

Section Outline:

• DESCRIPTION
• FORMS AND USES
• PATHOPHYSIOLOGY
• TOXIC DOSE
• EPIDEMIOLOGY
• CAUSES
• PREGNANCY
• WORKPLACE STANDARDS

DIFFERENTIAL DIAGNOSIS

• Toxic causes of cholinergic excess include organophosphate or carbamate insecticides, carbachol, methacholine, bethanechol, pilocarpine, and certain mushrooms.
• Nontoxic causes include myasthenia gravis and Eaton-Lambert syndrome.

SIGNS AND SYMPTOMS

Severe exposure may cause vomiting, confusion, agitation, and restlessness, followed by lethargy, seizures, and coma.

Vital Signs

• Tachycardia is common even with mild toxicity.
• Hypertension may be present early but pro-gresses to hypotension in serious cases.
• Hyperthermia may develop in severe toxicity.

HEENT

• Increased salivation and lacrimation are common.
• Initial miosis followed by mydriasis may occur.
• A burning sensation in mouth and throat may occur.

Dermatologic

Diaphoresis is common.

Pulmonary

Initial tachypnea is followed by respiratory depression.

Cardiovascular

• Sinus tachycardia is common.
• Initial tachycardia and hypertension followed by hypotension and bradycardia may occur.
• Cardiac dysrhythmia may occur in severe cases.

Gastrointestinal

• Nausea and vomiting are common.
• Abdominal pain and diarrhea also may occur.

Renal

Urinary incontinence occurs, especially in severe cases.

Neurologic

Headache, dizziness, and restlessness is followed by lethargy, seizure, and coma.

PROCEDURES AND LABORATORY TESTS

Essential Tests

• Serum electrolytes, glucose, BUN, creatinine, calcium, magnesium, and phosphate to detect other causes of dysrhythmia, weakness or kidney injury
• ECG and continuous monitoring to assess potential causes of hypotension and bradycardia.

Recommended Tests

• Cotinine levels in urine, plasma, and saliva correlate with passive exposure.
• Urine cotinine levels can be used to follow occupational exposure in tobacco pickers.

Not Recommended Tests

Nicotine levels are not clinically useful.

Section Outline:

• DIFFERENTIAL DIAGNOSIS
• SIGNS AND SYMPTOMS
  • Vital Signs
  • HEENT
  • Dermatologic
  • Pulmonary
  • Cardiovascular
  • Gastrointestinal
  • Renal
  • Neurologic
• PROCEDURES AND LABORATORY TESTS
  • Essential Tests
  • Recommended Tests
  • Not Recommended Tests

• Treatment should focus on decontamination, control of vomiting, support of hemodynamic function, and control of agitation.
• Dose and time of exposure should be determined for all substances involved.

DIRECTING PATIENT COURSE

The health-care professional should call a poison control center when:

• Seizure, hypotension, or serious dysrhythmia develops.
• Toxic effects are not consistent with nicotine poisoning.
• Coingestant, drug interaction, or underlying disease presents an unusual problem.

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 an unusual problem.

Admission Considerations

Inpatient treatment is warranted when the patient develops serious effects such as cardiac dysrhythmia, seizure, hypotension, persistent vomiting, or agitation.

DECONTAMINATION

Out of Hospital

Emesis is not recommended; seizures may develop quickly.

In Hospital

• Gastric lavage should be administered in pediatric (tube size 24-32 French) or adult (tube size 36-42 French) patients presenting within 1 hour of ingestion or if serious effects are present.
• Gastric lavage is not indicated following spontaneous vomiting.
• One dose of activated charcoal (1-2 g/kg) should be administered if a substantial ingestion has occurred within the previous few hours.
• Following a large ingestion or in patients who have serious signs or symptoms, one to two extra doses of activated charcoal (0.5-1.0 gm/kg) are indicated at 2- to 4-hour intervals.

ANTIDOTES

There is no specific antidote for nicotine poisoning.

ADJUNCTIVE TREATMENT

Seizures

• Airway should be monitored.
• A benzodiazepine familiar to the provider should be administered.
  • If diazepam is administered, the adult dose is 5 to 10 mg intravenously, pediatric dose 0.2 to 0.5 mg/kg intravenously, with the dose repeated at 10-minute intervals, titrating to effect.
  • If lorazepam is administered, the adult dose is 1 to 2 mg intravenously, pediatric dose 0.05 mg/kg intravenously, with the dose repeated at 10-minute intervals, titrating to effect.
  • If benzodiazepines do not control seizures or they recur, phenytoin or phenobarbital should be administered.

Cholinergic Excess

Atropine may be used for control of signs of cholinergic excess.

• The adult dose is 0.5 to 1.0 mg intravenously or intratracheally, repeated every 5 minutes up to a maximum of 0.04 mg/kg.
• Pediatric dose is 0.02 mg/kg intravenously, intratracheally, or intraosseously, repeated every 5 minutes up to a maximum dose of 1 mg in children and 2 mg in adolescents.

Section Outline:

• DIRECTING PATIENT COURSE
  • Admission Considerations
• DECONTAMINATION
  • Out of Hospital
  • In Hospital
• ANTIDOTES
• ADJUNCTIVE TREATMENT
  • Seizures
  • Cholinergic Excess

PATIENT MONITORING

Symptomatic patients require continuous cardiac and respiratory monitoring until signs and symptoms of toxicity resolve.

EXPECTED COURSE AND PROGNOSIS

• Signs and symptoms typically occur within 30 to 90 minutes.
• Mild exposures peak within a few hours, but severe poisoning may produce toxicity for 18 to 24 hours.
• Most patients recover without sequelae with supportive care alone.
• Deaths are usually due to respiratory failure and may occur as early as 1 hour postingestion.

DISCHARGE CRITERIA/INSTRUCTIONS

• From the emergency department
  • Patients who are asymptomatic after gastrointestinal decontamination and 4 to 6 hours of observation or after effects have resolved may be discharged.
  • A psychiatric evaluation should be provided if needed.
• From the hospital. Patients should be discharged after the effects have resolved and after psychiatric evaluation, if needed.

Section Outline:

• PATIENT MONITORING
• EXPECTED COURSE AND PROGNOSIS
• DISCHARGE CRITERIA/INSTRUCTIONS

Nicotine withdrawal symptoms may occur following chronic exposure, but would not be expected following an acute overdose.

Toxic effect of other substances, chiefly nonmedicinal as to source.

See Also: SECTION II, Seizures chapter; and SECTION III, Activated Charcoal chapter.

RECOMMENDED READING

Lavoie FW, Harris TM. Fatal nicotine ingestion. J Emerg Med 1991;9:133-136.

Woolf A, Burkhart K, Caraccio T, et al. Self-poisoning among adults using multiple transdermal nicotine patches. Clin Toxicol 1996;34:691-698.

Author: Benjamin Camp

Reviewer: Richard C. Dart