Acetaminophen 500 mg / phenyltoloxamine citrate 55 mg Oral Tablet [Zflex]
RxNorm 999398

Concept Hierarchy & Relationship Mapping

RxNorm Concept Unique Identifier (RxCUI) 999398 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: acetaminophen 500 mg / phenyltoloxamine citrate 55 mg Oral Tablet [Zflex].

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

SBD
Acetaminophen 500 mg / phenyltoloxamine citrate 55 mg Oral Tablet [Zflex]
AUI:12364222
View
SY
APAP 500 mg / Phenyltoloxamine citrate 55 mg Oral Tablet [Zflex]
AUI:3856961
View
SY
ZFLEX (acetaminophen 500 mg / phenyltoloxamine citrate 55 mg) Oral Tablet
AUI:3280422
View
SY
ZFLEX (APAP 500 mg / phenyltoloxamine citrate 55 mg) Oral Tablet
AUI:3608848
View

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

SBD

Semantic Branded Drug (SBD):
Acetaminophen 500 mg / phenyltoloxamine citrate 55 mg Oral Tablet [Zflex]
(Atom ID: 12364222)

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
acetaminophen 500 MG / phenyltoloxamine citrate 55 MG Oral Tablet [Zflex]
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
O
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
999398
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
12364222
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SBD
Semantic Branded Drug (Ingredient + Strength + Dose Form + Brand Name)
Source Code
999398
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
{315266} 161
RXCUI of BOSS Active Ingredient preceded by RXCUI of SCDC responsible for value
RXN AI
{476289} 221141
RXCUI of BOSS Active Ingredient preceded by RXCUI of SCDC responsible for value
RXN AM
{315266} 161
RXCUI of BOSS Active Moiety preceded by RXCUI of SCDC responsible for value
RXN AM
{476289} 33408
RXCUI of BOSS Active Moiety preceded by RXCUI of SCDC responsible for value
RXN BOSS FROM
{315266} 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
{476289} 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 OBSOLETED
07/01/2020
Date the RxNorm atom became obsolete
RXTERM FORM
Tab
The RxTerm dose form name for this drug
SY

Synonym (SY):
APAP 500 mg / Phenyltoloxamine citrate 55 mg Oral Tablet [Zflex]
(Atom ID: 3856961)

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
APAP 500 MG / Phenyltoloxamine citrate 55 MG Oral Tablet [Zflex]
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
O
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
999398
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
3856961
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SY
Synonym (Synonym of another TTY, given for clarity.)
Source Code
999398
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.
SY

Synonym (SY):
ZFLEX (acetaminophen 500 mg / phenyltoloxamine citrate 55 mg) Oral Tablet
(Atom ID: 3280422)

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
ZFLEX (acetaminophen 500 MG / phenyltoloxamine citrate 55 MG) Oral Tablet
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
O
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
999398
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
3280422
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SY
Synonym (Synonym of another TTY, given for clarity.)
Source Code
999398
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.
SY

Synonym (SY):
ZFLEX (APAP 500 mg / phenyltoloxamine citrate 55 mg) Oral Tablet
(Atom ID: 3608848)

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
ZFLEX (APAP 500 MG / phenyltoloxamine citrate 55 MG) Oral Tablet
Official description of the drug concept as defined in the source vocabulary.
Suppress Flag
O
N: Not suppressible | O: Obsolete | Y: Suppressed by editor | E: Unquantified non-prescribable drug.

Interoperability & Coding

Concept ID (RxCUI)
999398
RxNorm Unique Identifier for the standardized concept.
Atom ID (RXAUI)
3608848
Unique identifier for this specific name variation (Atom).
Term Type (TTY)
SY
Synonym (Synonym of another TTY, given for clarity.)
Source Code
999398
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.