Nicotine Drug Testing
Yes, cotinine measurement is the gold standard laboratory test for detecting nicotine use, with urine cotinine (cutoff 30 ng/mL) being the recommended first-line test due to its optimal balance of sensitivity, 7-day detection window, and ease of collection. 1
Primary Testing Method: Cotinine
Cotinine is the major metabolite of nicotine and provides superior sensitivity compared to other nicotine biomarkers. 1 The test can be performed on multiple specimen types with specific cutoff values 2, 1:
- Urine cotinine: 30 ng/mL (recommended first-line test)
- Serum/plasma cotinine: 3-5 ng/mL
- Saliva cotinine: 3-5 ng/mL
The half-life of cotinine is 16-18 hours, providing a biochemically verifiable detection window of up to 7 days after nicotine use. 2, 1 This extended window makes cotinine far more practical than other markers for clinical screening purposes.
Rapid point-of-care saliva cotinine dipstick tests are available and demonstrate 99% sensitivity and 96% specificity when compared to laboratory-based methods, making them suitable for immediate verification of smoking status in clinical settings. 3
Alternative Testing Methods
Carbon Monoxide (CO)
Exhaled CO can be measured with a cutoff of 5-6 ppm, but has significant limitations 2:
- Half-life of only 2-8 hours with a 1-day detection window
- Only detects combustible tobacco use (cigarettes)
- Does not detect smokeless tobacco or nicotine replacement therapy (NRT)
- Cannot distinguish tobacco smoking from marijuana smoking or other combustible exposures 2
A positive CO level alone is insufficient to confirm tobacco use in the era of vaping and cannabis use; combining CO with urine cotinine provides more robust assessment. 2
NNAL (Tobacco-Specific Nitrosamine Metabolite)
NNAL measured in urine (cutoff 47.3 pg/mL) offers unique advantages 2, 1:
- Half-life of 10-18 days, detectable in urine for 6-12 weeks
- Highly tobacco-specific
- Can distinguish NRT use from actual tobacco exposure (critical for patients in cessation programs)
- Detects smokeless tobacco use
For patients using NRT, add NNAL testing to distinguish therapeutic nicotine use from tobacco exposure. 1
Clinical Screening Tools
Beyond laboratory testing, validated screening questionnaires are available for adolescents and adults 2:
- CRAFFT 2.1+N: Ten-item questionnaire assessing past-year nicotine use with specific examples (JUUL, Puff Bars, vape pens)
- BSTAD (Brief Screener for Tobacco, Alcohol, and other Drugs): High sensitivity/specificity for identifying substance use
- S2BI (Screening to Brief Intervention): Queries past-year frequency with built-in intervention recommendations
Important Clinical Caveats
Cotinine cannot distinguish between NRT and tobacco use, as it detects nicotine from any source. 2 This limitation is clinically significant when monitoring patients in smoking cessation programs who are using nicotine patches, gum, or lozenges.
Self-reported smoking status is frequently inaccurate. Objective cotinine testing identified smokers who falsely reported being nonsmokers in validation studies. 3
For comprehensive nicotine dose estimation after low-level exposure, measuring the sum of multiple metabolites (cotinine + cotinine-glucuronide + trans-3'-hydroxycotinine + 3HC-glucuronide) in 24-hour urine collection provides the strongest correlation (r=0.96) with actual nicotine dose. 4