What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveBoth

LOINC Code 35631-1: PHENobarbital Screen [Mass/Vol]

Name: LOINC Code 35631-1: PHENobarbital Screen [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-25T17:13:11.347Z

35631-1 is a LOINC code used to identify PHENobarbital Screen [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. It is commonly used with the system or sample type Ser/Plas.

Reviewed by HealthAssure Clinical TeamUpdated 25 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. It is commonly used with the system or sample type Ser/Plas.

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: Both
Method: Screen

What it does not mean

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

Key facts

PHENobarbital [Mass/volume] in Serum or Plasma by Screen method
PHENobarbital
Barbiturate; c417; DRUG/TOXICOLOGY; Drugs; Level; Luminal; Mass concentration; Nirvonal; PHBR; Phenobarb; Pl; Plasma; Plsm; Point in time; QNT; Quan; Quant; Quantitative; Random; Scn; Scr; Scrn; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR

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.

Related SNOMED CT concepts

705114005SNOMED CT mapping for PHENobarbital Screen [Mass/Vol] (35631-1)

Related observations and tests

SNOMED_CT 705114005high

LOINC Code System

Source: LOINC-SNOMED cooperation package

Common synonyms

PHENobarbital Screen [Mass/Vol]PHENobarbital [Mass/volume] in Serum or Plasma by Screen methodPhenobarb SerPl Scn-mCncPHENobarbitalDRUG/TOXPHENobarbital, BloodMCnc

Frequently asked questions

Code details

Code35631-1

SystemLOINC

Display namePHENobarbital Screen [Mass/Vol]

DescriptionPHENobarbital

Short namePhenobarb SerPl Scn-mCnc

ComponentPHENobarbital

PropertyMCnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

MethodScreen

ClassDRUG/TOX

Example unitsug/mL

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.13

Last changed2.40

Consumer names

PHENobarbital, Blood

Part names

PHENobarbitalMCncPtSer/PlasQnScreenMass ConcentrationPoint in time (spot)Serum or PlasmaToxicology 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.