LOINCActive

LOINC Code 45240-9: Isoniazid therapy start date

45240-9 is a LOINC code used to identify Isoniazid therapy start date 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 Isoniazid therapy start date. It is commonly used with the system or sample type ^Patient.

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 Isoniazid therapy start date. It is commonly used with the system or sample type ^Patient.

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
  • Method: Reported

What it does not mean

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

Key facts

  • Isoniazid therapy start date
  • Hyzyd; ID; Infectious Disease; InfectiousDisease; INH; INH Rx start date; Isoniaz; Isoniazide; Nudrazod; Point in time; QNT; Quan; Quant; Quantitative; Random; Started

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

Isoniazid therapy start dateINH Rx start dateARTDatePt^PatientQn

Frequently asked questions

Code details

Code45240-9
SystemLOINC
Display nameIsoniazid therapy start date
Short nameINH Rx start date
ComponentIsoniazid therapy start date
PropertyDate
TimingPt
System (specimen)^Patient
ScaleQn
MethodReported
ClassART
Example unitsMMDDYY
StatusACTIVE

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.17
Last changed2.67

Part names

Isoniazid therapy start dateDatePt^PatientQnReportedPoint 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 45240-9 | HealthAssure