Cocaine detection model

Pharmacokinetic detection windows

MatrixMetaboliteWindow
UrineBenzoylecgonine (BZE)2–4 days (up to 7 heavy)
UrineCocaine parent6–12 h (occasional) to 5 days (heavy)
Oral fluidSmoked~6 h
Oral fluidOral~13 h
HairParent + metabolitesWeeks to months

Key metabolites: BZE (CES1 hydrolysis), EME (CES2 hydrolysis), norcocaine (CYP3A4 — active, hepatotoxic, minor).

Wearable detection strategy

Primary features

  1. HR delta from personal baseline — acute cocaine: ↑11–20+ bpm (cocaine alone); ↑20–40 bpm (with ethanol). Largest, most consistent signal.
  2. HRV suppression — acute sympathetic shift. Context: HRV is not interpretable as a recovery metric during intoxication.
  3. Same-night REM reduction — acute REM suppression is well-documented and consistent.
  4. Sleep efficiency drop — residual insomnia in 6–24 h window post-use.

Corroborating features

  • Motion context (cocaine intoxication typically occurs in sedentary/social context — distinguish from exercise HR spike)
  • Time-of-day pattern (evening/night use most common for recreational users)
  • HRV next-day trajectory (if still suppressed after 12–24 h, supports cocaine vs other acute stressor)

Route-specific notes

  • Smoked (crack): fastest onset (3–5 min), largest HR spike, shortest PK duration (~54 min half-life)
  • Intranasal: slower onset, more gradual HR rise, longer effective signal window
  • Oral: slowest onset, most delayed HR effect

Chronic vs occasional user detection

  • Occasional users: acute HR spike is large and clear; REM suppression same night is consistent
  • Chronic users: acute HR spike may be blunted by tolerance; but REM and sleep efficiency effects persist; next-day cognitive impairment may be more discriminating

Limitations

  • No wearable-specific HRV dataset for cocaine exists — all wearable inference is extrapolated from lab autonomic studies
  • Cocaethylene (cocaine + alcohol) complicates the model — HR elevation is amplified but detection window may overlap with alcohol
  • HR spike is not specific: exercise, stress, caffeine all produce similar patterns
  • Need motion + context + time-of-day to distinguish

Cocaine, Cardiovascular signatures, Cocaine sleep architecture, Cocaethylene, Cocaine crash