A review of biological indicators of illicit drug use, practical considerations and clinical usefulness

Aims. To examine a range of biological indicators of illicit drug use, incl uding blood, urine, hair and saliva, addressing both technological and prac tical issues relating to their application and interpretation. Methods. The review process involved an examination of Key reference texts and literatu re from the scientific fields of analytical and clinical toxicology. Findin gs. Urine remains the biological tool of choice for qualitative detection o f illicit drug use in a clinical setting, while quantitative accuracy remai ns strictly the domain of blood. The growing sophistication of laboratory a nalysis may additionally make possible the routine use of hair sampling whi ch can provide a much longer time frame for assessment. Breath, saliva, swe at or breast milk remain possibilities in the future. Conclusions. Accurate interpretation of the screening tests within a clinical setting alongside other relevant information remains the key to the usefulness of any test.