LOINCActiveObservation

LOINC Code 19668-3: PHENobarbital cutoff Screen (U) [Mass/Vol]

19668-3 is a LOINC code used to identify PHENobarbital cutoff Screen (U) [Mass/Vol] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component PHENobarbital cutoff. It is commonly used with the system or sample type Urine.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component PHENobarbital cutoff. It is commonly used with the system or sample type Urine.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: ACTIVE
  • Order vs observation: Observation
  • Method: Screen

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

  • PHENobarbital cutoff [Mass/volume] in Urine for Screen method
  • PHENobarbital cutoff
  • Barbiturate; c417; CtO; DRUG/TOXICOLOGY; Drugs; Level; Luminal; Mass concentration; Nirvonal; PHBR; Phenobarb; Point in time; QNT; Quan; Quant; Quantitative; Random; Scn; Scr; Scrn; UA; UR; Urn

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

PHENobarbital cutoff Screen (U) [Mass/Vol]PHENobarbital cutoff [Mass/volume] in Urine for Screen methodPhenobarb CtO Ur Scn-mCncPHENobarbital cutoffDRUG/TOXPHENobarbital cutoff, UrineMCnc

Frequently asked questions

Code details

Code19668-3
SystemLOINC
Display namePHENobarbital cutoff Screen (U) [Mass/Vol]
DescriptionPHENobarbital cutoff
Short namePhenobarb CtO Ur Scn-mCnc
ComponentPHENobarbital cutoff
PropertyMCnc
TimingPt
System (specimen)Urine
ScaleQn
MethodScreen
ClassDRUG/TOX
Example unitsng/mL
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0l
Last changed2.44

Consumer names

PHENobarbital cutoff, Urine

Part names

PHENobarbital cutoffMCncPtUrineQnScreenMass ConcentrationPoint in time (spot)Toxicology screen

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

LOINC Code 19668-3 | HealthAssure