Nicotine & Metabolites

Diagnosis

Indications for Testing

  • Document tobacco use – assess active exposure to nicotine and compliance with smoking cessation programs

Laboratory Testing

  • Nicotine has a short half-life – not always a good indicator of smoking status
    • Metabolized into several compounds that are measurable in urine and serum
      • Urine testing – recommended over serum/plasma to detect chronic use
        • Analytes detectable over a longer period of time to differentiate patient as the following
          • Active user
          • Abstinent >2 weeks
          • Passively exposed
          • Unexposed nonuser
      • Serum/plasma testing
        • Required when a valid urine specimen cannot be obtained (anuretic or dialysis patient)
        • Detects recent use – within past 2 weeks

Monitoring

  • Tobacco cessation
    • Measure urine concentrations of nicotine, cotinine, trans-'3-hydroxycotinine, nornicotine and anabasine
      • Plasma levels cannot differentiate between nicotine patch and tobacco use
  • Helpful in the following situations
    • Compliance with smoking cessation programs 
    • Candidates for orthopedic surgery and some other surgeries (eg, spinal fusion, wound revision, plastic surgery), pulmonary therapy, and organ transplantation
    • Identification of patients with unacknowledged tobacco use
  • Experimental nicotine therapy in cognitive degeneration disorders, (eg, Alzheimer disease, Parkinson disease, and attention deficit/hyperactivity disorder)

Pharmacogenetics and Therapeutic Drug Monitoring

  • Nicotine is extensively metabolized in the liver into the following
    • Cotinine – represents 70-80% of metabolized nicotine
      • Mediated by cytochrome P450 system (mainly CYP2A6 and CYP2B6)
      • Half-life – 20-24 hours
      • May be detected up to 7 days after nicotine exposure
    • Trans-3'-hydroxycotinine – a metabolite of cotinine
    • Nornicotine – a metabolite of nicotine
    • Anabasine – minor tobacco alkaloid
      • Check compliance with nicotine replacement therapy
        • Presence of anabasine suggests recent tobacco use or exposure
        • Absence of anabasine is not definitive evidence that tobacco was not used because anabasine concentrations are expected to vary with tobacco preparations
  • Plasma half-life for nicotine is 0.4-1.5 hours
  • Estimated detection window in urine is 3 days

Clinical Background

Use of tobacco products, particularly smoking, is a leading but preventable cause of disease, disability and death.

Epidemiology

  • Prevalence – 15-20% of adults are nicotine dependent
  • Sex – M>F

Pathophysiology

  • Nicotine is found in a variety of plants
  • Principle source of exposure – tobacco products or nicotine replacement therapy
  • Extensively metabolized by the liver
  • Absorbed through oral cavity, skin, urinary tract and gastrointestinal tract
  • Increases heart rate, blood pressure, mobilization of blood sugars and catecholamines

Clinical Presentation

  • Cancers – lung, larynx, oral and nasal cavity, paranasal sinuses, esophagus, pancreas, liver, stomach, cervix, leukemia (AML, CML, CLL)
  • Cardiac and neurologic disease – leading cause of coronary disease, stroke
  • Pulmonary disease – chronic obstructive pulmonary disease (includes chronic bronchitis and emphysema), asthma, respiratory infections, overall decrease in pulmonary function
  • Pregnancy – difficulty in conceiving, intrauterine growth retardation, low birth weight
  • Second-hand smoke – a confirmed human carcinogen implicated in pulmonary disease, lung cancer and coronary artery disease in non-smokers

Indications for Laboratory Testing

  • Tests generally appear in the order most useful for common clinical situations
  • Click on number for test-specific information in the ARUP Laboratory Test Directory
Test Name and Number Recommended Use Limitations Follow Up
Nicotine and Metabolites - Confirmation/Quantitation, Urine 0092356
Method: Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry

Detect nicotine, cotinine, trans-3'-hydroxycotinine, nornicotine and anabasine in urine

Presence of anabasine identifies tobacco use

Distinguish between categories of tobacco exposure and/or use – unexposed non-user passive exposure, abstinence (>2 weeks) and active users

Failure to detect anabasine is not definitive evidence of tobacco abstinence; interpretive questions should be directed to laboratory  
Nicotine and Metabolites - Confirmation/Quantitation, Serum or Plasma 0092361
Method: Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry

Detect and monitor nicotine, cotinine, and trans-3'-hydroxycotinine in serum or plasma

Order when valid urine specimen cannot be obtained (eg, anuretic or dialysis patient)

Does not detect anabasine

Interpretive questions should be directed to laboratory

 
Cotinine Screen, Urine 2007081
Method: Enzyme Multiplied Immunoassay Technique

Qualitative screen assesses active exposure to nicotine and compliance with smoking cessation programs

Analytical sensitivity – positive result reported at 100 ng/mL

May not differentiate between passive and active nicotine exposure

Will not differentiate nicotine exposure from nicotine replacement therapy and tobacco use