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 18335-0: Histamine H1 receptor antagonist Confirm Ql (U)

Name: LOINC Code 18335-0: Histamine H1 receptor antagonist Confirm Ql (U)
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:27.587Z

18335-0 is a LOINC code used to identify Histamine H1 receptor antagonist Confirm Ql (U) 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 Histamine H1 receptor antagonist. 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 Histamine H1 receptor antagonist. 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: Both
Method: Confirm

What it does not mean

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

Key facts

Histamine H1 receptor antagonist [Presence] in Urine by Confirmatory method
Histamine H1 receptor antagonist
Cfm; CNFR; CNFRM; Conf; Confirmation; Confirmatory; DRUG/TOXICOLOGY; Drugs; GCMS; H1 recep antag; LC/MS/MS; Ordinal; Point in time; PR; QL; Qual; Qualitative; Random; Rec; Recept; Receptors; Recp; Recptr; Screen; 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

Histamine H1 receptor antagonist Confirm Ql (U)Histamine H1 receptor antagonist [Presence] in Urine by Confirmatory methodH1 recep antag Ur Ql CfmHistamine H1 receptor antagonistDRUG/TOXHistamine H1 receptor antagonist, UrinePrThr

Frequently asked questions

Code details

Code18335-0

SystemLOINC

Display nameHistamine H1 receptor antagonist Confirm Ql (U)

DescriptionHistamine H1 receptor antagonist

Short nameH1 recep antag Ur Ql Cfm

ComponentHistamine H1 receptor antagonist

PropertyPrThr

TimingPt

System (specimen)Urine

ScaleOrd

MethodConfirm

ClassDRUG/TOX

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0l

Last changed2.82

Consumer names

Histamine H1 receptor antagonist, Urine

Part names

Histamine H1 receptor antagonistPrThrPtUrineOrdConfirmPresence or ThresholdPoint in time (spot)

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.