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United States· US:55289-479_30c8d0aa-5859-b584-e063-6394a90ac88e

Diphenhydramine HCl

A diphenhydramine product containing diphenhydramine hydrochloride, registered in United States by PD-Rx Pharmaceuticals, Inc.. The same ATC class is registered in 12 of our 19 countries.

ATC R06AA02US label

Checked against FDA National Drug Code directory (United States) on

Informational only — not a medical device.

SOURCE REGISTER · USFDA National Drug Code directory (Unite…normalisedDiphenhydramine HClATCR06AA02REGISTER NO.US:55289-479_30c8d0aa…PACKS LISTED12CHECKEDSeptember 27, 2026
Compare price across countriesPer daily dose · free accountAsk the assistant about diphenhydramine hydrochlorideAnswers with sources · free accountCheck interactionsSeverity free · mechanism on Growth

Where it is registered

Diphenhydramine is registered in 12 of 19 countries.

Countries holding a registration under ATC R06AA02 (diphenhydramine), each read from that country’s own register.

  • This record: United States, from FDA National Drug Code directory (United States)
  • 6 of them publish a price we can compare per daily dose
Search diphenhydramine products by name

Diphenhydramine · ATC R06AA02

12 / 19 countries

  • Belgiumprice
  • Canada
  • Denmark
  • Germany
  • Icelandprice
  • Ireland
  • Japan
  • Norwayprice
  • Polandprice
  • Switzerlandprice
  • United Kingdom
  • United Statesprice
Blue: a registration under this ATC code. The ringed marker is this record’s country. Markets marked price publish a price we can compare per daily dose.

The record

At a glance

FDA National Drug Code directory (United States)
Active substance
DIPHENHYDRAMINE HYDROCHLORIDE
Manufacturer
PD-Rx Pharmaceuticals, Inc.
Country
United States (US)
ATC code
R06AA02
ATC class
Diphenhydramine
Defined daily dose
0.2 g, O
Reimbursed
Not published by this register
Source register
FDA National Drug Code directory (United States)
Last checked
September 27, 2026

Packs & prices · 12

  • ndc11
    55289-479-10
  • ndc11
    5528947910
    10 CAPSULE in 1 BOTTLE, PLASTIC (55289-479-10)
  • ndc11
    5528947912
    12 CAPSULE in 1 BOTTLE, PLASTIC (55289-479-12)
  • ndc11
    5528947915
    15 CAPSULE in 1 BOTTLE, PLASTIC (55289-479-15)
  • ndc11
    5528947920
    20 CAPSULE in 1 BOTTLE, PLASTIC (55289-479-20)
  • ndc11
    5528947924
    24 CAPSULE in 1 BOTTLE, PLASTIC (55289-479-24)
  • ndc11
    5528947930
    30 CAPSULE in 1 BOTTLE, PLASTIC (55289-479-30)
  • ndc11
    55289-479-20
  • ndc11
    55289-479-24
  • ndc11
    55289-479-30
  • ndc11
    55289-479-12
  • ndc11
    55289-479-15

Regulatory notes

No shortage, Orange Book or US label notes for this record.

Interactions

469 interactions on record for diphenhydramine.

Graded by severity as the source publishes them — 14 severe. Severity grades are free for everyone; mechanism and management come with Growth.

  • Severity for every pair — free, no plan needed
  • The source, licence and sync date on every record
  • Mechanism and what to do for each pair — Growth plan
Check diphenhydramine against other medicinesHow interaction checks work

Diphenhydramine · interactions on record

469 records

  • 14 severe
  • 417 moderate
  • 2 minor

Most severe, free to view

  • Potassium chlorideA12BA01severe
  • Potassium citrateA12BA02severe
  • EliglustatA16AX10severe
  • Potassium chlorideB05XA01severe

36 more interactions with mechanism and management, from a commercially licensed source.

Sign in to check
  • Interaction severity from DDInter 2.0 (Xiong G. et al., Nucleic Acids Res.), licensed CC BY-NC 4.0 — free for non-commercial use only; not covered by the Drug Database commercial licence.
Mechanism and what to do, in the interaction check
Source: DDInter 2.0 · synced 29 Sept 2026. Grades as the source publishes them.

Same class

Other records under R06AA02

Diphenhydramine, as other registers publish it.

All diphenhydramine products

Sourced from a public register and reproduced with attribution. Drug Database is not affiliated with, endorsed by, or a partner of FDA National Drug Code directory (United States). This is an informational data service and not a medical device — verify against the official source of record before any clinical decision.

For developers

The same record over the API, and the raw payload
GET /v1/drugs/044b07c7-4d12-47d9-a3ac-cb45f78d38fa
GET /v1/drugs/044b07c7-4d12-47d9-a3ac-cb45f78d38fa?format=fhir

Every response carries last_synced_at, so freshness is a field rather than a promise. Below is exactly what the ingestion wrote, before any presentation — the same JSON the API returns under payload.

{
  "route": "ORAL",
  "source": "ndc",
  "strength": "25",
  "substance": "DIPHENHYDRAMINE HYDROCHLORIDE",
  "productndc": "55289-479",
  "dosage_form": "CAPSULE",
  "dea_schedule": null,
  "strength_unit": "mg/1",
  "application_number": "M010",
  "marketing_category": "OTC MONOGRAPH DRUG"
}
API referenceMCP serverPlans

See everything about diphenhydramine.

This page is the registration. A free account adds the label text as the regulator wrote it, what it costs per daily dose across the markets that publish a price, a feed of what changes in the registers, and an assistant that answers with its sources. Interaction severity is free; mechanism and management are on the Growth plan. No card, nothing to install.

Try it freeOpen in the console