Methyldopa 500 mg / hydroCHLOROthiazide 50 mg Oral Tablet
RxNorm 197961

Concept Hierarchy & Relationship Mapping

RxNorm Concept Unique Identifier (RxCUI) 197961 represents a standardized clinical drug concept used for cross-system interoperability. This concept aggregates multiple Atom IDs (AUIs), which are specific naming variations and synonyms used across pharmaceutical databases to ensure accurate medication mapping for: methyldopa 500 mg / hydroCHLOROthiazide 50 mg Oral Tablet.

The following semantic concepts and normalized strings are associated with this clinical entity:

SCD
Hydrochlorothiazide 50 mg / methyldopa 500 mg Oral Tablet
Primary clinical definition
AUI:12324542
View
SY
HCTZ 50 mg / methyldopa 500 mg Oral Tablet
AUI:3022836
View
TMSY
HydroCHLOROthiazide 50 mg / methyldopa 500 mg Oral Tablet
AUI:12428572
View
PT
Hydrochlorothiazide 50 mg and methyldopa 500 mg oral tablet
AUI:9251033
View
PSN
Methyldopa 500 mg / hydroCHLOROthiazide 50 mg Oral Tablet
AUI:12438108
View
FN
Product containing precisely hydrochlorothiazide 50 mg and methyldopa 500 mg/1 each conventional release oral tablet (clinical drug)
AUI:10313451
View

This clinical crossover tool is designed for healthcare professionals, pharmacists, and data analysts to safely compare substitute products and manage medication interoperability.

SCD

Semantic Clinical Drug (SCD):
Hydrochlorothiazide 50 mg / methyldopa 500 mg Oral Tablet
(Atom ID: 12324542)

Clinical Status & Identity

Prescribable Status
NO (Reference)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
hydrochlorothiazide 50 MG / methyldopa 500 MG Oral Tablet
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
N
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
197961
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
12324542
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SCD
Semantic Clinical Drug (Ingredient + Strength + Dose Form)
Source Code
197961
The "Most useful" identifier asserted by the original source vocabulary.

Source & Registry Data

Source Name
RxNorm Vocabulary (RXNORM)
The official name and abbreviation for the vocabulary source.
Source Version
20AA_260601F
The specific version of the vocabulary provided by the source.
Update Date
June 01, 2026
The date when this RxNorm data was last updated by the NLM.
License Contact
RxNorm Customer Service, , U.S. National Library of Medicine, 8600 Rockville Pike, , Bethesda, MD, United States, 20894, (888) FIND-NLM, , https://support.nlm.nih.gov/support/create-case/, https://www.nlm.nih.gov/research/umls/rxnorm/
Source licensing contact information.

Technical Attributes & Logic

RXN AI
{316051} 5487
RXCUI of BOSS Active Ingredient preceded by RXCUI of SCDC responsible for value
RXN AI
{317424} 6876
RXCUI of BOSS Active Ingredient preceded by RXCUI of SCDC responsible for value
RXN AM
{316051} 5487
RXCUI of BOSS Active Moiety preceded by RXCUI of SCDC responsible for value
RXN AM
{317424} 6876
RXCUI of BOSS Active Moiety preceded by RXCUI of SCDC responsible for value
RXN BOSS FROM
{316051} AI
Source of BOSS as either from the active ingredient (AI) or the active moiety (AM) preceded by RXCUI of SCDC responsible for value
RXN BOSS FROM
{317424} AI
Source of BOSS as either from the active ingredient (AI) or the active moiety (AM) preceded by RXCUI of SCDC responsible for value
RXTERM FORM
Tab
The RxTerm dose form name for this drug
SY

Synonym (SY):
HCTZ 50 mg / methyldopa 500 mg Oral Tablet
(Atom ID: 3022836)

Clinical Status & Identity

Prescribable Status
NO (Reference)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
HCTZ 50 MG / methyldopa 500 MG Oral Tablet
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
N
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
197961
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
3022836
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SY
Synonym (Synonym of another TTY, given for clarity.)
Source Code
197961
The "Most useful" identifier asserted by the original source vocabulary.

Source & Registry Data

Source Name
RxNorm Vocabulary (RXNORM)
The official name and abbreviation for the vocabulary source.
Source Version
20AA_260601F
The specific version of the vocabulary provided by the source.
Update Date
June 01, 2026
The date when this RxNorm data was last updated by the NLM.
License Contact
RxNorm Customer Service, , U.S. National Library of Medicine, 8600 Rockville Pike, , Bethesda, MD, United States, 20894, (888) FIND-NLM, , https://support.nlm.nih.gov/support/create-case/, https://www.nlm.nih.gov/research/umls/rxnorm/
Source licensing contact information.
TMSY

Tall Man Lettering Synonym (TMSY):
HydroCHLOROthiazide 50 mg / methyldopa 500 mg Oral Tablet
(Atom ID: 12428572)

Clinical Status & Identity

Prescribable Status
NO (Reference)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
hydroCHLOROthiazide 50 MG / methyldopa 500 MG Oral Tablet
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
N
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
197961
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
12428572
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
TMSY
Tall Man Lettering Synonym (Tall Man Lettering synonym of another TTY, given to distinguish between commonly confused drugs.)
Source Code
197961
The "Most useful" identifier asserted by the original source vocabulary.

Source & Registry Data

Source Name
RxNorm Vocabulary (RXNORM)
The official name and abbreviation for the vocabulary source.
Source Version
20AA_260601F
The specific version of the vocabulary provided by the source.
Update Date
June 01, 2026
The date when this RxNorm data was last updated by the NLM.
License Contact
RxNorm Customer Service, , U.S. National Library of Medicine, 8600 Rockville Pike, , Bethesda, MD, United States, 20894, (888) FIND-NLM, , https://support.nlm.nih.gov/support/create-case/, https://www.nlm.nih.gov/research/umls/rxnorm/
Source licensing contact information.
PT

Designated preferred name (PT):
Hydrochlorothiazide 50 mg and methyldopa 500 mg oral tablet
(Atom ID: 9251033)

Clinical Status & Identity

Prescribable Status
NO (Reference)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
Hydrochlorothiazide 50 mg and methyldopa 500 mg oral tablet
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
N
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
197961
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
9251033
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
PT
Designated preferred name ()
Source Code
377475005
The "Most useful" identifier asserted by the original source vocabulary.

Source & Registry Data

Source Name
US Edition of SNOMED CT (SNOMEDCT_US)
The official name and abbreviation for the vocabulary source.
Source Version
2026_01_31
The specific version of the vocabulary provided by the source.
Update Date
June 01, 2026
The date when this RxNorm data was last updated by the NLM.
License Contact
National Library Of Medicine, NLM is a Charter Member of SNOMED International on behalf of the U.S., National Library of Medicine, 8600 Rockville Pike, , Bethesda, MD, United States, 20894, 1-888-FIND-NLM (1-888-346-3656), , https://support.nlm.nih.gov/support/create-case/,
Source licensing contact information.
PSN

Prescribable Name (PSN):
Methyldopa 500 mg / hydroCHLOROthiazide 50 mg Oral Tablet
(Atom ID: 12438108)

Clinical Status & Identity

Prescribable Status
NO (Reference)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
methyldopa 500 MG / hydroCHLOROthiazide 50 MG Oral Tablet
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
N
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
197961
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
12438108
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
PSN
Prescribable Name (Synonym of another TTY, given for clarity and for display purposes in electronic prescribing applications. Only one PSN per concept.)
Source Code
197961
The "Most useful" identifier asserted by the original source vocabulary.

Source & Registry Data

Source Name
RxNorm Vocabulary (RXNORM)
The official name and abbreviation for the vocabulary source.
Source Version
20AA_260601F
The specific version of the vocabulary provided by the source.
Update Date
June 01, 2026
The date when this RxNorm data was last updated by the NLM.
License Contact
RxNorm Customer Service, , U.S. National Library of Medicine, 8600 Rockville Pike, , Bethesda, MD, United States, 20894, (888) FIND-NLM, , https://support.nlm.nih.gov/support/create-case/, https://www.nlm.nih.gov/research/umls/rxnorm/
Source licensing contact information.
FN

Full form of descriptor (FN):
Product containing precisely hydrochlorothiazide 50 mg and methyldopa 500 mg/1 each conventional release oral tablet (clinical drug)
(Atom ID: 10313451)

Clinical Status & Identity

Prescribable Status
NO (Reference)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
Product containing precisely hydrochlorothiazide 50 milligram and methyldopa 500 milligram/1 each conventional release oral tablet (clinical drug)
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
N
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
197961
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
10313451
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
FN
Full form of descriptor ()
Source Code
377475005
The "Most useful" identifier asserted by the original source vocabulary.

Source & Registry Data

Source Name
US Edition of SNOMED CT (SNOMEDCT_US)
The official name and abbreviation for the vocabulary source.
Source Version
2026_01_31
The specific version of the vocabulary provided by the source.
Update Date
June 01, 2026
The date when this RxNorm data was last updated by the NLM.
License Contact
National Library Of Medicine, NLM is a Charter Member of SNOMED International on behalf of the U.S., National Library of Medicine, 8600 Rockville Pike, , Bethesda, MD, United States, 20894, 1-888-FIND-NLM (1-888-346-3656), , https://support.nlm.nih.gov/support/create-case/,
Source licensing contact information.

Patient Education

Methyldopa and Hydrochlorothiazide


The combination of methyldopa and hydrochlorothiazide is used to treat high blood pressure. Methyldopa works by relaxing the blood vessels so that blood can flow more easily through the body. Hydrochlorothiazide helps to lower blood pressure by eliminating unneeded water and salt from the body. High blood pressure is a common condition and when not treated, can cause damage to the brain, heart, blood vessels, kidneys and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressure. These changes include eating a diet that is low in fat and salt, maintaining a healthy weight, exercising at least 30 minutes most days, not smoking, and using alcohol in moderation.
[Learn More]


Blood Pressure Medicines


High blood pressure, also called hypertension, usually has no symptoms. But it can cause serious problems such as stroke, heart failure, heart attack and kidney failure. If you cannot control your high blood pressure through lifestyle changes such as losing weight and reducing sodium in your diet, you may need medicines.

Blood pressure medicines work in different ways to lower blood pressure. Some remove extra fluid and salt from the body. Others slow down the heartbeat or relax and widen blood vessels. Often, two or more medicines work better than one.

NIH: National Heart, Lung, and Blood Institute


[Learn More]


* Please review the disclaimer below.