Aims: To examine a range of biological indicators of illicit drug use, including blood, urine, hair and saliva, addressing both technological and practical issues relating to their application and interpretation.
Methods: The review process involved an examination of key reference texts and literature from the scientific fields of analytical and clinical toxicology.
Findings: Urine remains the biological tool of choice for qualitative detection of illicit drug use in a clinical setting, while quantitative accuracy remains strictly the domain of blood. The growing sophistication of laboratory analysis may additionally make possible the routine use of hair sampling which can provide a much longer time frame for assessment. Breath, saliva, sweat 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.