Concept Hierarchy & Relationship Mapping
RxNorm Concept Unique Identifier (RxCUI) 5509 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: p-dihydroxybenzene.
The following semantic concepts and normalized strings are associated with this clinical entity:
Type (TTY)
Clinical Name / Synonym
Atom ID
Details
This clinical crossover tool is designed for healthcare professionals, pharmacists, and data analysts to safely compare substitute products and manage medication interoperability.
SYPrescribable
Synonym (SY):
Hydroquinol
(Atom ID: 172830)
Clinical Status & Identity
Prescribable Status
YES (Active)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
Hydroquinol
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)
5509
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
172830
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SY
Synonym (Synonym of another TTY, given for clarity.)
Source Code
387422001
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.
UNII Crosswalk
XV74C1N1AE - HYDROQUINONE (INGREDIENT SUBSTANCE)
RxNorm to Unique Ingredient Identifier crosswalk.
INPrescribable
Ingredient (IN):
Hydroquinone
(Atom ID: 172807)
Clinical Status & Identity
Prescribable Status
YES (Active)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
hydroquinone
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)
5509
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
172807
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
IN
Ingredient (A compound or moiety that gives the drug its distinctive clinical properties. Ingredients generally use the United States Adopted Name (USAN).)
Source Code
5509
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.
UNII Crosswalk
XV74C1N1AE - HYDROQUINONE (INGREDIENT SUBSTANCE)
RxNorm to Unique Ingredient Identifier crosswalk.
PTPrescribable
Designated preferred name (PT):
Hydroquinone
(Atom ID: 172815)
Clinical Status & Identity
Prescribable Status
YES (Active)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
Hydroquinone
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)
5509
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
172815
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
PT
Designated preferred name ()
Source Code
387422001
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.
UNII Crosswalk
XV74C1N1AE - HYDROQUINONE (INGREDIENT SUBSTANCE)
RxNorm to Unique Ingredient Identifier crosswalk.
FNPrescribable
Full form of descriptor (FN):
Hydroquinone (substance)
(Atom ID: 172836)
Clinical Status & Identity
Prescribable Status
YES (Active)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
Hydroquinone (substance)
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)
5509
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
172836
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
FN
Full form of descriptor ()
Source Code
387422001
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.
UNII Crosswalk
XV74C1N1AE - HYDROQUINONE (INGREDIENT SUBSTANCE)
RxNorm to Unique Ingredient Identifier crosswalk.
PTPrescribable
Designated preferred name (PT):
Hydroquinone-containing product
(Atom ID: 10804698)
Clinical Status & Identity
Prescribable Status
YES (Active)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
Hydroquinone-containing product
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)
5509
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
10804698
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
PT
Designated preferred name ()
Source Code
74583006
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.
UNII Crosswalk
XV74C1N1AE - HYDROQUINONE (INGREDIENT SUBSTANCE)
RxNorm to Unique Ingredient Identifier crosswalk.
SYPrescribable
Synonym (SY):
P-dihydroxybenzene
(Atom ID: 11441674)
Clinical Status & Identity
Prescribable Status
YES (Active)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
p-dihydroxybenzene
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)
5509
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
11441674
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SY
Synonym (Synonym of another TTY, given for clarity.)
Source Code
387422001
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.
UNII Crosswalk
XV74C1N1AE - HYDROQUINONE (INGREDIENT SUBSTANCE)
RxNorm to Unique Ingredient Identifier crosswalk.
SYPrescribable
Synonym (SY):
Para-dihydroxybenzene
(Atom ID: 172822)
Clinical Status & Identity
Prescribable Status
YES (Active)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
Para-dihydroxybenzene
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)
5509
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
172822
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SY
Synonym (Synonym of another TTY, given for clarity.)
Source Code
387422001
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.
UNII Crosswalk
XV74C1N1AE - HYDROQUINONE (INGREDIENT SUBSTANCE)
RxNorm to Unique Ingredient Identifier crosswalk.
FNPrescribable
Full form of descriptor (FN):
Product containing hydroquinone (medicinal product)
(Atom ID: 9724562)
Clinical Status & Identity
Prescribable Status
YES (Active)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
Product containing hydroquinone (medicinal product)
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)
5509
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
9724562
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
FN
Full form of descriptor ()
Source Code
74583006
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.
UNII Crosswalk
XV74C1N1AE - HYDROQUINONE (INGREDIENT SUBSTANCE)
RxNorm to Unique Ingredient Identifier crosswalk.
SYPrescribable
Synonym (SY):
Quinol
(Atom ID: 172824)
Clinical Status & Identity
Prescribable Status
YES (Active)
Part of the RxNorm Current Prescribable Content subset including all drugs available for prescription in the USA.
Concept Description
Quinol
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)
5509
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
172824
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SY
Synonym (Synonym of another TTY, given for clarity.)
Source Code
387422001
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.
UNII Crosswalk
XV74C1N1AE - HYDROQUINONE (INGREDIENT SUBSTANCE)
RxNorm to Unique Ingredient Identifier crosswalk.
