HomeNDC LookupIngredientsHydralazine Hydrochloride › 51662-1388-01
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HYDRALAZINE HYDROCHLORIDE 20 mg/mL Injection, 1 mL

by HF Acquisition Co LLC, DBA HealthFirst · 1 mL in 1 VIAL, SINGLE-DOSE (51662-1388-1)
NDC 51662-1388-01
🏷️ FDA NDC (as labeled) 51662-1388-1 billing pads the package segment with a zero
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 →

🆔 Identity & classification

FDA NDC (as labeled) 51662-1388-1
Product NDC 51662-1388
11-digit billing NDC 51662138801
RxCUI 966571
UNII FD171B778Y
Application # ANDA040730
SPL Set ID 94530e4d-b1c0-6171-e053-2a95a90a05fa
Established class (EPC) Arteriolar Vasodilator
Physiologic effect Arteriolar Vasodilation
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2019-10-07
Route INTRAMUSCULAR, INTRAVENOUS
Dosage form INJECTION
Substance HYDRALAZINE HYDROCHLORIDE
TE code (Orange Book) AP · RLD · RS
Why two NDCs? The FDA registers this code as 51662-1388-1 — a 5-4-1 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 package segment → 51662-1388-01. 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 Arteriolar Vasodilator class.

Pharmacologic class Arteriolar Vasodilator
Drug family (ATC) Hydrazinophthalazine derivatives
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

LabelerHF Acquisition Co LLC, DBA HealthFirst
Application holderRISING PHARMA HOLDINGS INC
FDA applicationANDA040730 (ANDA)
Labeler code51662
First marketedOct 2019
Product typeHuman Prescription Drug
Portfolio333 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

📗 Our plain-language guide HelloPharmacist
  • Hydralazine is used to treat high blood pressure (hypertension). The tablet form is taken at home on a daily schedule, while the injectable form is reserved for hospital use when b...
  • It works by relaxing the walls of your arteries, which allows them to widen. When arteries are wider, blood flows through them more easily and your blood pressure drops. It's not a...
  • How does hydralazine lower my blood pressure?
  • Common side effects include headache, nausea, a fast heartbeat, flushing, and dizziness — these often settle as your body adjusts or if your dose is tweaked. You should call your d...
📖 Read our full Hydralazine guide →
2
Nutrient depletion considerations

Hydralazine may be associated with lower levels of 2 nutrients — worth a chat with your pharmacist, not a cause for alarm.

An association is not a deficiency. Educational only — don't start or stop anything without professional guidance.
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.
  • 0.65 mg / 1 mL UNII A2I8C7HI9T
    Methylparaben is a preservative derived from benzoic acid that prevents growth of bacteria, fungi, and mold in medicines. It extends the product's shelf life and maintains safety during storage.
  • 103.6 mg / 1 mL UNII 6DC9Q167V3
    Propylene glycol is a clear liquid derived from petroleum or vegetable sources. It acts as a solvent, humectant, and preservative in medicines, helping dissolve active ingredients and maintain product stability.
  • 0.35 mg / 1 mL UNII Z8IX2SC1OH
    Propylparaben is a chemical preservative used to prevent bacterial and fungal growth in medicines and personal care products. It helps extend shelf life and maintain product safety during storage.
  • 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.

6 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 DailyMedingredient 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 eachPer 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.
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
Hydralazine Hydrochloride 20 mg/mL 00404-9787-01 Henry 1 vial AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 00517-0901-25 American 25 vials AP FDA listed
HydrALAZINE hydrochloride 20 mg/mL 00641-6231-25 Hikma 25 vials AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 43066-0041-25 Baxter 25 vials AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 51662-1376-01 HF 1 ml AP FDA listed
Hydralazine Hydrochloride 20 mg/mLthis 51662-1388-01 HF 1 ml AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 51662-1648-03 HF 25 pouches AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 55150-0400-25 Eugia 25 vials AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 55154-9554-05 Cardinal 5 vials AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 55154-9587-05 Cardinal 5 vials AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 63323-0614-55 Fresenius 25 vials AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 68475-0514-02 Navinta 25 vials AP FDA listed
hydrALAZINE Hydrochloride 20 mg/mL 70518-3659-01 REMEDYREPACK 25 vials AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 70710-1988-07 Zydus 25 vials AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 71288-0205-02 Meitheal 25 vials AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 71872-7145-01 Medical 1 vial AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 71872-7268-01 Medical 1 vial AP FDA listed
HydrALAZINE hydrochloride 20 mg/mL 71872-7274-01 Medical 1 vial AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 71872-7339-01 Medical 1 vial AP FDA listed
Hydralazine Hydrochloride 20 mg/mL 72572-0265-25 Civica, 25 vials AP FDA listed
hydrALAZINE Hydrochloride 20 mg/mL 84549-0614-55 ProPharma 1 ml 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
Oct 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 Hydralazine Hydrochloride — the ingredient across all brands.

Top reported reactions

Chronic Kidney Disease2,858
Acute Kidney Injury2,684
Renal Failure2,137
Fatigue1,631
Dyspnoea1,624
End Stage Renal Disease1,609
Diarrhoea1,500

Age at onset

Neonate144
Infant22
Child15
Adolescent25
Adult1,969
Elderly3,004

Reporter sex

29,962 reports
Male · 46%
Female · 54%
Unknown · 0%

Serious outcomes

Hospitalization12,795
Death3,674
Life-threatening1,403
Disabling680
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 3,454 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 Marketing startStatus
51662-1388-01 You're viewing this 1 mL in 1 VIAL, SINGLE-DOSE (51662-1388-1) 2019-10-07 Active

🧭 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 — Not published for this NDC No photo available yet for this listing.
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 51662-1388-1, 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: 51662-1388-01, written without dashes as 51662138801. 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 51662-1388-01, the first segment (51662) is the labeler code FDA assigned to HF Acquisition Co LLC, DBA HealthFirst; the middle segment (1388) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (01) 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 HF Acquisition Co LLC, DBA HealthFirst. Listing status can change — the directory data on this page refreshes weekly.
Who lists this product with the FDA?
HF Acquisition Co LLC, DBA HealthFirst 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 24 words

Indications & Usage Severe essential hypertension when the drug cannot be given orally or when there is an urgent need to lower blood pressure.

⏱️ Dosage and Administration 178 words

Dosage & Administration When there is urgent need, therapy in the hospitalized patient may be initiated intramuscularly or as a rapid intravenous bolus injection directly into the vein. Hydralazine hydrochloride injection should be used only when the drug cannot be given orally. The usual dose is 20 to 40 mg, repeated as necessary.

Certain patients (especially those with marked renal damage) may require a lower dose. Blood pressure should be checked frequently. It may begin to fall within a few minutes after injection, with the average maximal decrease occurring in 10 to 80 minutes.

In cases where there has been increased intracranial pressure, lowering the blood pressure may increase cerebral ischemia. Most patients can be transferred to oral hydralazine hydrochloride within 24 to 48 hours. The product should be used immediately after the vial is opened.

It should not be added to infusion solutions. Hydralazine hydrochloride injection may discolor upon contact with metal; discolored solutions should be discarded. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

Contraindications 12 words

Contraindications Hypersensitivity to hydralazine; coronary artery disease; mitral valvular rheumatic heart disease.

⚠️ Warnings 64 words

Warnings In a few patients hydralazine may produce a clinical picture simulating systemic lupus erythematosus including glomerulonephritis. In such patients hydralazine should be discontinued unless the benefit-to-risk determination requires continued antihypertensive therapy with this drug. Symptoms and signs usually regress when the drug is discontinued but residua have been detected many years later.

Long-term treatment with steroids may be necessary (see PRECAUTIONS, Laboratory Tests).

🤒 Adverse Reactions 52 words

Adverse Reactions Adverse reactions with hydralazine hydrochloride are usually reversible when dosage is reduced. However, in some cases it may be necessary to discontinue the drug. The following adverse reactions have been observed, but there has not been enough systematic collection of data to support an estimate of their frequency. Adverse Reactions

🆘 Overdosage 107 words

Overdosage Signs and Symptoms: Signs and symptoms of overdosage include hypotension, tachycardia, headache, and generalized skin flushing. Complications can include myocardial ischemia and subsequent myocardial infarction, cardiac arrhythmia, and profound shock. Treatment: There is no specific antidote.

Support of the cardiovascular system is of primary importance. Shock should be treated with plasma expanders. If possible, vasopressors should not be given, but if a vasopressor is required, care should be taken not to precipitate or aggravate cardiac arrhythmia.

Tachycardia responds to beta blockers. Digitalization may be necessary, and renal function should be monitored and supported as required. No experience has been reported with extracorporeal or peritoneal dialysis.

Overdosage

🧬 Clinical Pharmacology 204 words

Clinical Pharmacology Although the precise mechanism of action of hydralazine is not fully understood, the major effects are on the cardiovascular system. Hydralazine apparently lowers blood pressure by exerting a peripheral vasodilating effect through a direct relaxation of vascular smooth muscle. Hydralazine, by altering cellular calcium metabolism, interferes with the calcium movements within the vascular smooth muscle that are responsible for initiating or maintaining the contractile state.

The peripheral vasodilating effect of hydralazine results in decreased arterial blood pressure (diastolic more than systolic), decreased peripheral vascular resistance, and an increased heart rate, stroke volume, and cardiac output. The preferential dilatation of arterioles, as compared to veins, minimizes postural hypotension and promotes the increase in cardiac output. Hydralazine usually increases renin activity in plasma, presumably as a result of increased secretion of renin by the renal juxtaglomerular cells in response to reflex sympathetic discharge.

This increase in renin activity leads to the production of angiotensin II, which then causes stimulation of aldosterone and consequent sodium reabsorption. Hydralazine also maintains or increases renal and cerebral blood flow. The average maximal decrease in blood pressure usually occurs 10 to 80 minutes after administration of hydralazine hydrochloride injection.

No other pharmacokinetic data on hydralazine hydrochloride injection are available.

📦 How Supplied / Storage and Handling 74 words

How Supplied HYDRALAZINE HYDROCHLORIDE INJECTION, USP is supplied in the following dosage forms. NDC 51662-1388-1 HYDRALAZINE HYDROCHLORIDE INJECTION, USP 20mg/mL 1mL VIAL HF Acquisition Co LLC, DBA HealthFirst Mukilteo, WA 98275 Also supplied in the following manufacture supplied dosage forms Hydralazine Hydrochloride Injection USP, 20 mg/mL Storage: Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Akorn Manufactured by: Akorn, Inc.

Lake Forest, IL 60045 HY00N Rev. 06/16 How Supplied

📋 Description 124 words

Description Hydralazine Hydrochloride Injection, USP is an antihypertensive available in a 1 mL vial for intravenous and intramuscular administration. Hydralazine Hydrochloride Injection, USP is a sterile, nonpyrogenic colorless solution. Each mL contains: Active: Hydralazine Hydrochloride USP, 20 mg Preservatives: Methylparaben NF, 0.65 mg; Propylparaben NF, 0.35 mg Inactives: Propylene Glycol USP, 103.6 mg; Sodium Hydroxide and/or Hydrochloric Acid USP to adjust pH (3.4 to 4.4) and Water for Injection.

Hydralazine Hydrochloride USP is 1-hydrazinophthalazine monohydrochloride, and its structural formula is: Molecular Formula C8H8N4•HCl Hydralazine Hydrochloride USP is a white to off-white, odorless crystalline powder. It is soluble in water, slightly soluble in alcohol, and very slightly soluble in ether. It melts at about 275°C, with decomposition, and has a molecular weight of 196.64.

Structure

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
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.