LOINCActiveObservation

LOINC Code 1646-9: Xylose post dose PO (5 hour U) [Mass/Time]

1646-9 is a LOINC code used to identify Xylose post dose PO (5 hour U) [Mass/Time] 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 Xylose^post dose PO. 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 Xylose^post dose PO. 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

What it does not mean

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

Key facts

  • Xylose [Mass/time] in 5 hour Urine --post dose PO
  • Xylose^post dose PO
  • 5 hours; 5.0Hr; 5HR; After; CHEMISTRY.CHALLENGE TESTING; D-xylose; Mass rate; mRate; p dose; p PO; PST; QNT; Quan; Quant; Quantitative; UA; UR; Urn; Xylose absorption test

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

Xylose post dose PO (5 hour U) [Mass/Time]Xylose [Mass/time] in 5 hour Urine --post dose POXylose p PO 5h Ur-mRateXylose^post dose POCHALXylose after dose by mouth, UrineMRat

Frequently asked questions

Code details

Code1646-9
SystemLOINC
Display nameXylose post dose PO (5 hour U) [Mass/Time]
DescriptionXylose^post dose PO
Short nameXylose p PO 5h Ur-mRate
ComponentXylose^post dose PO
PropertyMRat
Timing5H
System (specimen)Urine
ScaleQn
ClassCHAL
Example unitsg/5 H
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.73

Consumer names

Xylose after dose by mouth, Urine

Part names

Xylose^post dose POMRat5HUrineQnMass Rate5 hours

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 1646-9 | HealthAssure