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DIPHENHYDRAMINE 50 mg/mL Injection, Solution, 5 vials — NDC 42571-0337-78 package photo

DIPHENHYDRAMINE 50 mg/mL Injection, Solution, 5 vials

by Micro Labs Limited · 5 VIAL in 1 CARTON (42571-337-78) / 1 mL in 1 VIAL
NDC 42571-0337-78
🏷️ FDA NDC (as labeled) 42571-337-78 billing pads the product segment with a zero
This package
Contains5 vials Pack sizes3 compare ↓
Also comes in: 1 mL 42571-0337-56 25 vials 42571-0337-87
Rx only Generic On market Non-controlled
🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

This page is curated, coded, and maintained by

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

🆔 Identity & classification

FDA NDC (as labeled) 42571-337-78
Product NDC 42571-337
11-digit billing NDC 42571033778
RxCUI 1723740
UNII TC2D6JAD40
UPC 0342571337957, 0342571169541
Application # ANDA205723
SPL Set ID a1110433-498a-48cb-ac79-5732fd4f8fba
Established class (EPC) Histamine-1 Receptor Antagonist
Mechanism of action Histamine H1 Receptor Antagonists
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2019-12-10
Route INTRAMUSCULAR, INTRAVENOUS
Dosage form INJECTION, SOLUTION
Substance DIPHENHYDRAMINE HYDROCHLORIDE
TE code (Orange Book) AP · RLD · RS
Why two NDCs? The FDA registers this code as 42571-337-78 — a 5-3-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the product segment → 42571-0337-78. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏷️ RxNorm drug class

This medicine belongs to the Histamine-1 Receptor Antagonist class.

Pharmacologic class Histamine-1 Receptor Antagonist
Drug family (ATC) Propionic acid derivatives, Antihistamines for topical use, Aminoalkyl ethers
How it works Histamine H1 Receptor Antagonists
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerMicro Labs Limited
Application holderMICRO LABS LTD
FDA applicationANDA205723 (ANDA)
Labeler code42571
First marketedDec 2019
Product typeHuman Prescription Drug
Portfolio190 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

📖 What it is MedlinePlus · NLM

Diphenhydramine injection is used to treat allergic reactions, motion sickness and to control abnormal movements in people who have Parkinsonian syndrome (a disorder of the nervous system that causes difficulties with movement, muscle control, and balance). Diphenhydramine injection is in a class of medications called antihistamines. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms.

Read the full MedlinePlus article ↗
📗 Our plain-language guide HelloPharmacist
  • Diphenhydramine is mainly used to temporarily ease the stuffy, sneezy, itchy symptoms of allergies — like hay fever — and the common cold. Think runny nose, sneezing, watery or itc...
  • What exactly does diphenhydramine treat?
  • Yes, and that's one of the most important things to know about this medicine. Drowsiness is one of its most common effects — it crosses into the brain and that's what causes the se...
  • It depends on your child's age and the product. Most oral diphenhydramine products are not recommended for children under 6, and liquid products labeled for children are generally...
📖 Read our full Diphenhydramine guide →

Supplement & herbal interactions

🌿 Drug–supplement interaction checker →
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

🧪 Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

  • UNII QTT17582CB
    A strong acid used to adjust and maintain the proper pH level in liquid medicines, ensuring stability and preventing breakdown of active ingredients.
  • UNII 55X04QC32I
    A strong alkaline chemical used to adjust and maintain the pH balance of liquid medicines. It helps keep the medicine stable and ensures it stays effective during storage.
  • UNII 059QF0KO0R
    Water is a liquid solvent that dissolves and mixes ingredients together in liquid medicines, syrups, and injections. It helps distribute the active drug evenly throughout the product.

3 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMed — ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer mLPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · quarterly No Part D plan price is available for this NDC in our data.
ℹ️
No price is published for this exact package yet. CMS surveys NADAC per package size, so a different pack of the same drug often has one.
Try another pack size: 1 mL 25 vials
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Diphenhydramine Hydrochloride 50 mg/mL 23155-0263-31 Heritage 1 vial $0.790 AP FDA listed —
Diphenhydramine hydrochloride 50 mg/mL 00641-6282-25 Hikma 25 vials $0.934 AP Availability likely —
Diphenhydramine Hydrochloride 50 mg/mL 23155-0264-41 Heritage 25 vials $0.934 AP Availability likely —
Diphenhydramine Hydrochloride 50 mg/mL 25021-0481-01 Sagent 25 vials $0.934 AP Availability likely —
Diphenhydramine 50 mg/mL 63323-0664-01 Fresenius 25 vials $0.934 AP Availability likely —
Diphenhydramine Hydrochloride 50 mg/mL 72485-0101-25 Armas 25 vials $0.934 AP Availability likely —
Diphenhydramine 50 mg/mL 83634-0781-01 Avenacy, 25 vials $0.934 AP Availability likely —
Diphenhydramine Hydrochloride 50 mg/mL 00641-0376-25 Hikma 25 vials $0.934 AP Availability likely —
Diphenhydramine Hydrochloride 50 mg/mL 00404-9851-01 Henry 1 vial — AP FDA listed —
Diphenhydramine 50 mg/mL 42571-0169-55 Micro 10 ampules — AP FDA listed —
Diphenhydramine 50 mg/mLthis 42571-0337-78 Micro 5 vials — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 51662-1219-01 HF 1 ml — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 51662-1348-01 HF 1 ml — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 51662-1374-01 HF 1 ml — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 55154-9363-05 Cardinal 5 vials — AP FDA listed —
Diphenhydramine 50 mg/mL 65219-0820-01 Fresenius 25 vials — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 68083-0611-25 Gland 25 vials — AP FDA listed —
Diphenhydramine hydrochloride 50 mg/mL 70518-4455-00 REMEDYREPACK 25 vials — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 70518-4536-00 REMEDYREPACK 25 vials — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 71872-7005-01 Medical 1 vial — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 71872-7180-01 Medical 1 vial — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 71872-7373-01 Medical 1 vial — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 84549-0101-25 ProPharma 1 ml — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 55154-5102-05 Cardinal 5 vials — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 70518-1082-01 REMEDYREPACK 25 vials — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 76045-0235-10 Fresenius 1 syringe — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 42571-0511-56 Micro 1 vial — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 76045-0102-10 Fresenius 1 syringe — AP FDA listed —
Diphenhydramine Hydrochloride 50 mg/mL 85766-0253-25 Sportpharm 25 vials — AP FDA listed —
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

⏳ Availability & generic status

🏛️
2019
On the market since
Dec 2019
📍
2026
Currently FDA-listed
7 years listed
🔓
·
Generic on the market
this product is a generic
✅This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

🔬 Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for DIPHENHYDRAMINE (this brand).

Top reported reactions

Fatigue7,934
Headache7,601
Nausea6,748
Pain6,599
Infusion Related Reaction5,711
Arthralgia5,403
Toxicity To Various Agents5,094

Age at onset

Neonate84
Infant116
Child1,275
Adolescent905
Adult11,190
Elderly4,461

Reporter sex

80,878 reports
Male · 35%
Female · 65%
Unknown · 0%

Serious outcomes

Hospitalization26,478
Death15,219
Life-threatening4,233
Disabling1,672
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 11,889 0
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

📦 Packaging — all sizes for this product

Package NDCDescription Per unit Per pack Marketing startStatus
42571-0337-87 25 VIAL in 1 CARTON (42571-337-87) / 1 mL in 1 VIAL (42571-337-95) $0.9336 / mL $23.34 2019-12-10 Active
42571-0337-56 1 VIAL in 1 CARTON (42571-337-56) / 1 mL in 1 VIAL — — 2026-03-05 Active
42571-0337-78 You're viewing this 5 VIAL in 1 CARTON (42571-337-78) / 1 mL in 1 VIAL — — 2026-03-03 Active

Pack size FAQ

What quantity is in NDC 42571-0337-78?
NDC 42571-0337-78 contains 5 vials — 5 vial in 1 carton / 1 ml in 1 vial.
What is the difference between NDC 42571-0337-78 and NDC 42571-0337-56?
Both are DIPHENHYDRAMINE 50 mg/mL Injection, Solution — the drug itself is identical. NDC 42571-0337-78 is the 5 vials package, while NDC 42571-0337-56 is the 1 vial package.
What NDC number is used to bill for this package of DIPHENHYDRAMINE 50 mg/mL Injection, Solution?
Bill NDC 42571-0337-78 — the 11-digit billing format is 42571033778. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.

🧭 About this NDC listing & data coverage

Finished prescription product
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos ✓ Available
Inactive ingredients (structured) ✓ Available
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data ✓ Available
HCPCS J-code billing crosswalk — Not published for this NDC Most self-administered / retail products have no J-code — that is normal.
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The FDA registers it as 42571-337-78, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 42571-0337-78, written without dashes as 42571033778. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 42571-0337-78, the first segment (42571) is the labeler code FDA assigned to Micro Labs Limited; the middle segment (0337) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (78) identifies this exact package size and type. Together they name one specific package of one specific product.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Micro Labs Limited. Listing status can change — the directory data on this page refreshes weekly.
Does this product come in other package sizes?
Yes — the FDA directory lists 2 other package presentations of this same product, including 1 vial (42571-0337-56), 25 vials (42571-0337-87). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
Micro Labs Limited is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage ⏱️ Dosage and Administration ⛔ Contraindications ⚠️ Warnings 🤒 Adverse Reactions 🔄 Drug Interactions 🤰 Pregnancy 🧒 Pediatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 📦 How Supplied / Storage and Handling 📋 Description 💬 Information for Patients
🎯 Indications and Usage 135 words ▾

INDICATIONS AND USAGE Diphenhydramine hydrochloride in the injectable form is effective in adults and pediatric patients, other than premature infants and neonates, for the following conditions when diphenhydramine hydrochloride in the oral form is impractical. Antihistaminic For amelioration of allergic reactions to blood or plasma, in anaphylaxis as an adjunct to epinephrine and other standard measures after the acute symptoms have been controlled, and for other uncomplicated allergic conditions of the immediate type when oral therapy is impossible or contraindicated.

Motion sickness For active treatment of motion sickness. Antiparkinsonism For use in parkinsonism, when oral therapy is impossible or contraindicated, as follows: parkinsonism in the elderly who are unable to tolerate more potent agents; mild cases of parkinsonism in other age groups, and in other cases of parkinsonism in combination with centrally acting anticholinergic agents.

⏱️ Dosage and Administration 127 words ▾

DOSAGE AND ADMINISTRATION THIS PRODUCT IS FOR INTRAVENOUS OR INTRAMUSCULAR ADMINISTRATION ONLY. Diphenhydramine hydrochloride in the injectable form is indicated when the oral form is impractical. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

DOSAGE SHOULD BE INDIVIDUALIZED ACCORDING TO THE NEEDS AND THE RESPONSE OF THE PATIENT. Pediatric Patients, other than premature infants and neonates 5 mg/kg/24 hr or 150 mg/m 2 /24 hr. Maximum daily dosage is 300 mg.

Divide into four doses, administered intravenously at a rate generally not exceeding 25 mg/min, or deep intramuscularly. Adults 10 to 50 mg intravenously at a rate generally not exceeding 25 mg/min, or deep intramuscularly, 100 mg if required; maximum daily dosage is 400 mg.

⛔ Contraindications 87 words ▾

CONTRAINDICATIONS Use in Neonates or Premature Infants This drug should not be used in neonates or premature infants. Use in Nursing Mothers Because of the higher risk of antihistamines for infants generally, and for neonates and prematures in particular, antihistamine therapy is contraindicated in nursing mothers. Use as a Local Anesthetic Because of the risk of local necrosis, this drug should not be used as a local anesthetic.

Antihistamines are also contraindicated in the following conditions Hypersensitivity to diphenhydramine hydrochloride and other antihistamines of similar chemical structure.

⚠️ Warnings 102 words ▾

WARNINGS Antihistamines should be used with considerable caution in patients with narrow-angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, symptomatic prostatic hypertrophy, or bladder-neck obstruction. Local necrosis has been associated with the use of subcutaneous or intradermal use of intravenous diphenhydramine hydrochloride injection. Use in Pediatric Patients In pediatric patients, especially, antihistamines in overdosage may cause hallucinations, convulsions, or death.

As in adults, antihistamines may diminish mental alertness in pediatric patients. In the young pediatric patient, particularly, they may produce excitation. Use in the Elderly (approximately 60 years or older) Antihistamines are more likely to cause dizziness, sedation, and hypotension in elderly patients.

🤒 Adverse Reactions 108 words ▾

ADVERSE REACTIONS The most frequent adverse reactions are underscored. 1. General: Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of mouth, nose, and throat.

2. Cardiovascular System: Hypotension, headache, palpitations, tachycardia, extrasystoles. 3.

Hematologic System: Hemolytic anemia, thrombocytopenia, agranulocytosis. 4. Nervous System: Sedation, sleepiness, dizziness, disturbed coordination , fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, neuritis, convulsions.

5. GI System: Epigastric distress , anorexia, nausea, vomiting, diarrhea, constipation. 6.

GU System: Urinary frequency, difficult urination, urinary retention, early menses. 7. Respiratory System: Thickening of bronchial secretions , tightness of chest or throat and wheezing, nasal stuffiness.

🔄 Drug Interactions 28 words ▾

Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). MAO inhibitors prolong and intensify the anticholinergic (drying) effects of antihistamines.

🤰 Pregnancy 72 words ▾

Pregnancy Pregnancy Category B. Reproduction studies have been performed in rats and rabbits at doses up to 5 times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to diphenhydramine hydrochloride. There are, however, no adequate and well-controlled studies in pregnant women.

Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

🧒 Pediatric Use 49 words ▾

Pediatric Use Diphenhydramine hydrochloride should not be used in neonates and premature infants (see CONTRAINDICATIONS ). Diphenhydramine hydrochloride injection may diminish mental alertness, or, in the young pediatric patient, cause excitation. Overdosage may cause hallucinations, convulsions, or death (see WARNINGS and OVERDOSAGE ). See also DOSAGE AND ADMINISTRATION section.

🆘 Overdosage 48 words ▾

OVERDOSAGE Antihistamine overdosage reactions may vary from central nervous system depression to stimulation. Stimulation is particularly likely in pediatric patients. Atropine-like signs and symptoms; dry mouth; fixed, dilated pupils; flushing; and gastrointestinal symptoms may also occur. Stimulants should not be used. Vasopressors may be used to treat hypotension.

🧬 Clinical Pharmacology 81 words ▾

CLINICAL PHARMACOLOGY Diphenhydramine hydrochloride is an antihistamine with anticholinergic (drying) and sedative side effects. Antihistamines appear to compete with histamine for cell receptor sites on effector cells. Diphenhydramine hydrochloride in the injectable form has a rapid onset of action.

Diphenhydramine hydrochloride is widely distributed throughout the body, including the CNS. A portion of the drug is excreted unchanged in the urine, while the rest is metabolized via the liver. Detailed information on the pharmacokinetics of Diphenhydramine Hydrochloride Injection is not available.

📦 How Supplied / Storage and Handling 175 words ▾

HOW SUPPLIED Diphenhydramine Hydrochloride Injection, USP in parenteral form is supplied as: Sterile, pyrogen-free solution containing 50 mg diphenhydramine hydrochloride USP in a 1 mL amber color glass ampule with yellow bands and white OPC mark, and available in packages of ten packed in a PVC rondo tray in a single carton. 1 mL fill in 1 mL Ampule NDC 42571-169-54 Carton of 10 x 1 mL Ampule NDC 42571-169-55 Clear, colorless solution, free from any visible particles, no visible leaks or damage to the container closure system filled in tubular USP Type I glass vials.

1 mL fill in 2 mLVial NDC 42571-337-95 Carton of 1 mL Vial NDC 42571-337-56 Carton of 25 x 1 mL Vial NDC 42571-337-87 Carton of 5 x 1 mL Vial NDC 42571-337-78 Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Protect from freezing and light. Retain in carton until time of use.

Rx only Manufactured by: Micro Labs Limited Bangalore-560 099, India. Manufactured for: Micro Labs USA, Inc. Somerset, NJ 08873 Rev.

03/2026

📋 Description 100 words ▾

DESCRIPTION Diphenhydramine hydrochloride USP is an antihistamine drug having the chemical name 2-(Diphenylmethoxy)-N,N-dimethylethylamine hydrochloride. It occurs as a white, crystalline powder, is freely soluble in water and alcohol and has a molecular weight of 291.82. The molecular formula is C 17 H 21 NO • HCI.

The structural formula is as follows: Diphenhydramine hydrochloride USP in the parenteral form is a sterile, pyrogen-free solution available in a concentration of 50 mg of diphenhydramine hydrochloride USP per mL. The solutions for parenteral use have been adjusted to a pH between 4 and 6.5 with either sodium hydroxide or hydrochloric acid. structure

💬 Information for Patients 44 words ▾

Information for Patients Patients taking diphenhydramine hydrochloride should be advised that this drug may cause drowsiness and has an additive effect with alcohol. Patients should be warned about engaging in activities requiring mental alertness such as driving a car or operating appliances, machinery, etc.

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
← 42571-0336-90 · Micro 42571-0341-01 · Micro →
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.