Methyldopa 250 mg / chlorothiazide 250 mg Oral Tablet
RxNorm 197959

Concept Hierarchy & Relationship Mapping

RxNorm Concept Unique Identifier (RxCUI) 197959 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 250 mg / chlorothiazide 250 mg Oral Tablet.

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

SCD
Chlorothiazide 250 mg / methyldopa 250 mg Oral Tablet
Primary clinical definition
AUI:12325051
PT
Chlorothiazide 250 mg and methyldopa 250 mg oral tablet
AUI:9249481
PSN
Methyldopa 250 mg / chlorothiazide 250 mg Oral Tablet
AUI:6365768
FN
Product containing precisely chlorothiazide 250 mg and methyldopa 250 mg/1 each conventional release oral tablet (clinical drug)
AUI:10310549

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):
Chlorothiazide 250 mg / methyldopa 250 mg Oral Tablet
(Atom ID: 12325051)

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
chlorothiazide 250 MG / methyldopa 250 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)
197959
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
12325051
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SCD
Semantic Clinical Drug (Ingredient + Strength + Dose Form)
Source Code
197959
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
{315638} 2396
RXCUI of BOSS Active Ingredient preceded by RXCUI of SCDC responsible for value
RXN AI
{316283} 6876
RXCUI of BOSS Active Ingredient preceded by RXCUI of SCDC responsible for value
RXN AM
{315638} 2396
RXCUI of BOSS Active Moiety preceded by RXCUI of SCDC responsible for value
RXN AM
{316283} 6876
RXCUI of BOSS Active Moiety preceded by RXCUI of SCDC responsible for value
RXN BOSS FROM
{315638} 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
{316283} 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

PT

Designated preferred name (PT):
Chlorothiazide 250 mg and methyldopa 250 mg oral tablet
(Atom ID: 9249481)

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
Chlorothiazide 250 mg and methyldopa 250 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)
197959
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
9249481
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
PT
Designated preferred name ()
Source Code
377278005
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 250 mg / chlorothiazide 250 mg Oral Tablet
(Atom ID: 6365768)

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 250 MG / chlorothiazide 250 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)
197959
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
6365768
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
197959
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 chlorothiazide 250 mg and methyldopa 250 mg/1 each conventional release oral tablet (clinical drug)
(Atom ID: 10310549)

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 chlorothiazide 250 milligram and methyldopa 250 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)
197959
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
10310549
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
FN
Full form of descriptor ()
Source Code
377278005
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

Chlorothiazide


Chlorothiazide is used alone or in combination with other medications to treat high blood pressure. Chlorothiazide is used to treat edema (fluid retention; excess fluid held in body tissues) caused by various medical problems, including heart, kidney, and liver disease and to treat edema caused by using certain medications including estrogen and corticosteroids. Chlorothiazide is in a class of medications called diuretics ('water pills'). It works by causing the kidneys to get rid of unneeded water and salt from the body into the urine. High blood pressure is a common condition, and when not treated it 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]


Methyldopa


Methyldopa is used to treat high blood pressure. Methyldopa is in a class of medications called antihypertensives. It works by relaxing the blood vessels so that blood can flow more easily through 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]


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