What are the detection windows for ketamine and cocaine in blood, saliva, urine, and hair?

Detection Windows for Ketamine and Cocaine

Ketamine is detectable in urine for 24-72 hours after single use, while cocaine metabolites remain detectable for 24-48 hours in typical users, though chronic heavy users may test positive for up to 22 days.

Ketamine Detection Times

Urine Detection

• Standard detection window: 24-72 hours after ingestion for single use 1
• Extended detection with sensitive methods: Up to 5-6 days for ketamine itself and up to 10 days for its metabolite dehydronorketamine when using ultra-high pressure liquid chromatography with detection limits of 0.03-0.05 ng/mL 2
• Chronic users: Dramatically prolonged excretion profiles of 22-96 days have been documented in chronic daily ketamine users, with peak detection periods of 61 days for ketamine, 40 days for norketamine, and 96 days for dehydronorketamine 3

Blood Detection

• Ketamine can be detected in bloodstream for approximately 24 hours after ingestion 1
• Blood testing is most useful for detecting use within 2-12 hours and correlates best with impairment level 1

Hair Testing

• Hair testing allows detection of past use over extended periods (typically 90 days using first 3 cm of hair) 1
• Cannot detect use in the previous 7-10 days due to time required for drug incorporation into hair matrix 1
• Limit of detection for ketamine in hair is 0.03-0.05 ng/mg 4

Saliva Detection

• Saliva testing detects recent use within 24-48 hours 1
• Less invasive than blood and allows detection of drug excreted from blood that may not yet be detectable in urine 1

Cocaine Detection Times

Urine Detection

• Standard detection window: 24-48 hours after typical use 1
• The cocaine metabolite benzoylecgonine has a urinary half-life of 6-8 hours 1
• Mean time to first negative specimen: 43.6 ± 17.1 hours (range 16-66 hours) after intranasal cocaine use 1
• Chronic heavy users: Benzoylecgonine detectable up to 22 days after last ingestion in individuals using up to 10 g/day 1, 5
• Standard immunoassay cut-off is 300 ng/mL for benzoylecgonine 1

Blood and Hair Detection

• Cocaine can be detected in blood and hair, though blood testing is primarily useful for acute presentations 1
• Blood concentrations are most useful for detecting use within 2-12 hours 1

Saliva and Sweat Detection

• Saliva: Detects use within 24-48 hours 1
• Sweat patches: Detect cocaine and metabolites (benzoylecgonine and ecgonine methyl ester) from use occurring 48 hours before patch application and throughout the 3-7 day wear period 6
• Sweat patches provide continuous monitoring but are subject to environmental contamination and less standardization than urine or blood tests 1, 6

Critical Clinical Considerations

Timing of Testing

• Both drugs have short detection windows, requiring toxicology screening as soon as possible when drug-facilitated scenarios are suspected 1
• Testing should potentially be performed before completing history and physical examination in time-sensitive situations 1

Testing Limitations

• Standard drug-screening panels may not include ketamine or specific cocaine metabolites 1
• Healthcare professionals should inquire about proper specimen collection and which specific drugs can be detected by their laboratory 1
• Individual variability in metabolism and excretion affects quantitative results 1

Chronic Use Monitoring

• Chronic ketamine users require frequent measurements (at least weekly) due to prolonged excretion profiles and large interindividual variation in metabolism 3
• Cocaine users with persistent use after initial presentation have higher rates of recurrent cardiac events and mortality 1