LOINCActiveBoth

LOINC Code 50543-8: Tricyclic antidepressants (U) [Mass/Vol]

50543-8 is a LOINC code used to identify Tricyclic antidepressants (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 Tricyclic antidepressants. It is commonly used with the system or sample type Urine.

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 Tricyclic antidepressants. 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

What it does not mean

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

Key facts

  • Tricyclic antidepressants [Mass/volume] in Urine
  • Tricyclic antidepressants
  • Antidepres; Antidepressant; DRUG/TOXICOLOGY; Drugs; Level; Mass concentration; Point in time; QNT; Quan; Quant; Quantitative; Random; TCA; Tricyclics; 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

Tricyclic antidepressants (U) [Mass/Vol]Tricyclic antidepressants [Mass/volume] in UrineTricyclics Ur-mCncTricyclic antidepressantsDRUG/TOXTricyclic antidepressants, UrineMCnc

Frequently asked questions

Code details

Code50543-8
SystemLOINC
Display nameTricyclic antidepressants (U) [Mass/Vol]
DescriptionTricyclic antidepressants
Short nameTricyclics Ur-mCnc
ComponentTricyclic antidepressants
PropertyMCnc
TimingPt
System (specimen)Urine
ScaleQn
ClassDRUG/TOX
Example unitsng/mL
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.22
Last changed2.73

Consumer names

Tricyclic antidepressants, Urine

Part names

Tricyclic antidepressantsMCncPtUrineQnMass ConcentrationPoint 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.

LOINC Code 50543-8 | HealthAssure