Clinical laboratories in Donostia, Gasteiz and Bilbao
RPS 131/24Privacy
Combined pathway

Urine drug testing

Screens urine for groups of substances or metabolites. A presumptive positive may require confirmation with a specific analytical technique.

SampleFresh urine in a suitable container; identity checks and chain of custody for occupational, legal or administrative use.
FastingNo fasting required.
Indicative turnaroundScreening can be rapid; chromatographic/mass-spectrometric confirmation is referred and takes several days.
PathwayCombined pathway
Available atDonostia · Gasteiz · Bilbo

Why it is performed

  • Perform clinical, occupational, sports, administrative or legal testing with the correct panel and safeguards.
  • Detect recent exposure to substance classes included in the screen.
  • Confirm and identify a specific substance when the result has important consequences.

How it is performed

The person collects the specimen under instructions without adding water or products. Formal testing documents identity, temperature, seals, signatures, transport and each transfer. Local screening uses cut-offs; confirmation is performed at a partner laboratory.

Preparation

  • Declare all prescribed and over-the-counter medicines and supplements; some substances can interfere with immunoassays.
  • Do not try to 'clean' or dilute the sample; it may be reported as invalid or adulterated.
  • State before collection if a legal chain-of-custody report is required.

How Askabide processes it

Combined pathway

Immunochromatographic or immunological screening by drug class using device-defined cut-offs. Specific confirmations use GC-MS or LC-MS/MS according to the partner laboratory and purpose.

Part is performed at Askabide and another phase or confirmation is processed externally.

Results and indicative intervals

Intervals vary by method, analyser, reagent, units, age, sex, pregnancy, menstrual-cycle phase and reference population. The valid interval is the one printed on the laboratory report.
Parameter or resultIndicative referenceHow it is interpreted
NegativePor debajo del punto de corteDoes not mean absolute absence; the substance may be below the cut-off or outside the detection window.
Presumptive positiveIgual o superior al punto de corteThis is a screening result and must be confirmed when clinical, occupational or legal consequences are involved.
ConfirmedSustancia/metabolito identificadoThe confirmation method identifies and, where applicable, quantifies the specific analyte.
Invalid/adulteratedNueva muestraTemperature, creatinine, specific gravity, pH or control abnormalities may prevent interpretation.

Important limitations

  • Each substance has a different detection window affected by dose, frequency, metabolism and specimen.
  • Class screens can cross-react with medicines or miss new/unlisted substances.
  • A result alone does not prove intoxication, impairment, dose or exact time of use.
  • Tests with legal consequences require consent, identification and chain of custody.
This website provides general information about clinical laboratory tests and diagnostic procedures. It does not replace an individual clinical assessment or the interpretation of the report issued by the laboratory.
Published reference values are indicative and may vary according to the method, equipment, units and individual characteristics.