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Allopurinol 300 mg Tablet, 90-count — NDC 71205-0377-90 package photo

Allopurinol 300 mg Tablet, 90-count

by Proficient Rx LP · 90 TABLET in 1 BOTTLE, PLASTIC (71205-377-90)
NDC 71205-0377-90
🏷️ FDA NDC (as labeled) 71205-377-90 billing pads the product segment with a zero
This package
Contains90-count Pack sizes3 compare ↓
Also priced by: Part D plans $0.1123/unit — full pricing hub ↓
Also comes in: 30 tablets 71205-0377-30 60 tablets 71205-0377-60
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) 71205-377-90
Product NDC 71205-377
11-digit billing NDC 71205037790
NCPDP billing unit EA — each (per item)
RxCUI 197320
UNII 63CZ7GJN5I
UPC 0371205377908
Application # ANDA071450
SPL Set ID b20c6ed4-6b94-4a1b-b448-e910856fa825
Established class (EPC) Xanthine Oxidase Inhibitor
Mechanism of action Xanthine Oxidase Inhibitors
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 1987-01-09
Route ORAL
Dosage form TABLET
Substance ALLOPURINOL
GPI-14 68000010000310
GPI class Allopurinol
GCN Seq No 002536
GCN 07071
HICL code 001100
Ingredient (HICL) Allopurinol
HIC1 code C
Therapeutic class — broad (HIC1) Electrolyte Balance/Metabolism/Nutrition
HIC2 code C7
Therapeutic class — intermediate (HIC2) Metabolic Inhibitors And Stimulants
HIC3 code C7A
Therapeutic class — specific (HIC3) Hyperuricemia Tx - Xanthine Oxidase Inhibitors
AHFS code 92:16.00.00
AHFS class Antigout Agents
FDB label name ALLOPURINOL 300 MG TABLET
FDB brand name Allopurinol
Legend status F — Federal legend — prescription drug or device
TE code (Orange Book) AB · RLD · RS
Why two NDCs? The FDA registers this code as 71205-377-90 — 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 → 71205-0377-90. 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 Xanthine Oxidase Inhibitor class.

Pharmacologic class Xanthine Oxidase Inhibitor
Drug family (ATC) Preparations inhibiting uric acid production
How it works Xanthine Oxidase Inhibitors
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

LabelerProficient Rx LP
Application holderSUN PHARMACEUTICAL INDUSTRIES INC
FDA applicationANDA071450 (ANDA)
Labeler code71205
First marketedJan 1987
Product typeHuman Prescription Drug
Portfolio1,723 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

Label name ALLOPURINOL 300 MG TABLET Ingredient Allopurinol
📖 What it is MedlinePlus · NLM

Allopurinol is used to treat gout (a type of arthritis in which uric acid, a naturally occurring substance in the body, builds up in the joints and causes sudden attacks of redness, swelling, pain, and heat in one or more joints). Allopurinol is also used to treat high levels of uric acid that builds up in the blood as tumors break down in people with certain types of cancer who are being treated with chemotherapy medications. It is also used to treat kidney stones that have come back in people who have high levels of uric acid in their urine. Allopurinol is in a class of medications called xa...

Read the full MedlinePlus article ↗
📗 Our plain-language guide HelloPharmacist
  • Gout is caused by too much uric acid building up in your blood, which then forms sharp crystals in your joints — causing those painful flares. Allopurinol works by blocking the enz...
  • Why did my doctor prescribe allopurinol, and how does it actually help my gout?
  • This is really common and it doesn't mean the medicine isn't working. When uric acid levels start to drop, it can shake loose uric acid crystals from your tissues, temporarily trig...
  • I started allopurinol and I'm actually getting more gout attacks — should I stop taking it?
📖 Read our full Allopurinol guide →
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.

💊 What it looks like

Color Orange
ShapeRound
ImprintMP;80
Size12 mm
ScoringScored — splits in 2
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

🧪 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.

A current SPL was checked, but it does not contain a structured or narrative inactive-ingredient list for this product. This does not mean the product has no inactive ingredients.
Where does this data come from?
Source: official FDA Structured Product Labeling (SPL) via DailyMed and the openFDA label index. Structured IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.

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 · Q2 2026 $0.1123 $10.11 / 90 tablets
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
Allopurinol 300 mg 00378-0181-01 Mylan 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 00591-5544-01 Actavis 100 tablets $0.055 — Availability likely —
Allopurinol 300 mg 00603-2116-21 Par 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 00904-6572-61 Major 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 16571-0885-09 Rising 90 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 16714-0577-01 NorthStar 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 23155-0694-01 Heritage 100 tablets $0.055 AB Discontinued —
Allopurinol 300 mg 29300-0350-01 Unichem 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 31722-0253-01 Camber 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 51079-0206-20 Mylan 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 53489-0157-01 Sun 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 55111-0730-01 Dr. 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 59651-0286-01 Aurobindo 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 60687-0688-01 American 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 62135-0517-31 Chartwell 300 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 69315-0292-01 Leading 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 71921-0242-01 Florida 100 tablets $0.055 AB Availability likely —
Allopurinol 300 mg 16729-0135-01 Accord 100 tablets $0.075 AB FDA listed —
Allopurinol 300 mg 00615-8517-05 NCS 15 tablets — AB FDA listed —
Allopurinol 300 mg 14445-0171-00 Indoco 1000 tablets — AB FDA listed —
Allopurinol 300 mg 43063-0934-01 PD-Rx 100 tablets — AB FDA listed —
Allopurinol 300 mg 43063-0976-30 PD-Rx 30 tablets — AB FDA listed —
Allopurinol 300 mg 43353-0186-60 Aphena 90 tablets — AB FDA listed —
Allopurinol 300 mg 48433-0003-20 Safecor 100 tablets — AB FDA listed —
Allopurinol 300 mg 50090-4663-00 A-S 100 tablets — AB FDA listed —
Allopurinol 300 mg 50090-6882-00 A-S 100 tablets — AB FDA listed —
Allopurinol 300 mg 50090-6968-00 A-S 90 tablets — AB FDA listed —
Allopurinol 300 mg 50090-7351-00 A-S 100 tablets — AB FDA listed —
Allopurinol 300 mg 50090-7353-00 A-S 90 tablets — AB FDA listed —
Allopurinol 300 mg 50090-7792-00 A-S 100 tablets — AB FDA listed —
Allopurinol 300 mg 51655-0782-26 Northwind 90 tablets — AB FDA listed —
Allopurinol 300 mg 51655-0968-26 Northwind 90 tablets — AB FDA listed —
Allopurinol 300 mg 55154-5454-00 Cardinal 10 tablets — AB FDA listed —
Allopurinol 300 mg 55154-7981-00 Cardinal 10 tablets — AB FDA listed —
Allopurinol 300 mg 60760-0722-90 ST. 90 tablets — AB FDA listed —
Allopurinol 300 mg 60760-0989-90 St. 90 tablets — AB FDA listed —
Allopurinol 300 mg 63187-0240-30 Proficient 30 tablets — AB FDA listed —
Allopurinol 300 mg 63629-1781-01 Bryant 30 tablets — AB FDA listed —
Allopurinol 300 mg 63629-2112-01 Bryant 500 tablets — AB FDA listed —
Allopurinol 300 mg 63629-2113-01 Bryant 1000 tablets — AB FDA listed —
Allopurinol 300 mg 67046-0681-03 Coupler 30 tablets — AB FDA listed —
Allopurinol 300 mg 67046-1514-03 Coupler 30 tablets — AB FDA listed —
Allopurinol 300 mg 67046-1639-03 Coupler 30 tablets — AB FDA listed —
Allopurinol 300 mg 67046-1658-03 Coupler 30 tablets — AB FDA listed —
Allopurinol 300 mg 67544-0313-45 Aphena 45 tablets — AB FDA listed —
Allopurinol 300 mg 68071-3605-09 NuCare 90 tablets — AB FDA listed —
Allopurinol 300 mg 68071-3672-09 NuCare 90 tablets — AB FDA listed —
Allopurinol 300 mg 68788-6323-01 Preferred 100 tablets — AB FDA listed —
Allopurinol 300 mg 68788-8364-01 Preferred 100 tablets — AB FDA listed —
Allopurinol 300 mg 68788-8424-01 Preferred 100 tablets — AB FDA listed —
Allopurinol 300 mg 68788-8713-01 Preferred 100 tablets — AB FDA listed —
Allopurinol 300 mg 68788-8865-01 Preferred 100 tablets — AB FDA listed —
Allopurinol 300 mg 70518-3704-00 REMEDYREPACK 30 tablets — AB FDA listed —
Allopurinol 300 mg 70518-4286-00 REMEDYREPACK 30 tablets — AB FDA listed —
Allopurinol 300 mg 70518-4404-00 REMEDYREPACK 30 tablets — AB FDA listed —
Allopurinol 300 mg 70518-4556-00 REMEDYREPACK 100 tablets — AB FDA listed —
Allopurinol 300 mg 70710-1210-00 Zydus 1000 tablets — AB FDA listed —
Allopurinol 300 mg 70771-1127-00 Zydus 1000 tablets — AB FDA listed —
Allopurinol 300 mg 71205-0049-30 Proficient 30 tablets — AB FDA listed —
Allopurinol 300 mgthis 71205-0377-90 Proficient 90 tablets — AB FDA listed —
Allopurinol 300 mg 71335-0112-01 Bryant 30 tablets — AB FDA listed —
Allopurinol 300 mg 71335-2332-01 Bryant 30 tablets — AB FDA listed —
Allopurinol 300 mg 71335-3082-01 Bryant 30 tablets — AB FDA listed —
Allopurinol 300 mg 71335-9634-01 Bryant 30 tablets — AB FDA listed —
Allopurinol 300 mg 71335-9676-01 Bryant 30 tablets — AB FDA listed —
Allopurinol 300 mg 71610-0064-45 Aphena 45 tablets — AB FDA listed —
Allopurinol 300 mg 71610-0253-60 Aphena 90 tablets — AB FDA listed —
Allopurinol 300 mg 71610-0681-45 Aphena 45 tablets — AB FDA listed —
Allopurinol 300 mg 72162-1150-00 Bryant 1000 tablets — AB FDA listed —
Allopurinol 300 mg 72189-0417-90 Direct_Rx 90 tablets — AB FDA listed —
Allopurinol 300 mg 72189-0647-90 Direct_Rx 90 tablets — AB FDA listed —
Allopurinol 300 mg 72865-0304-01 XLCare 100 tablets — AB FDA listed —
Allopurinol 300 mg 80425-0206-01 Advanced 30 tablets — AB FDA listed —
Allopurinol 300 mg 80425-0383-01 Advanced 30 tablets — AB FDA listed —
Allopurinol 300 mg 80425-0518-01 Advanced 30 tablets — AB FDA listed —
Allopurinol 300 mg 82638-0113-02 Harman 100 tablets — AB FDA listed —
Allopurinol 300 mg 82868-0099-30 Northwind 30 tablets — AB FDA listed —
Allopurinol 300 mg 70518-4693-00 REMEDYREPACK 100 tablets — AB FDA listed —
Allopurinol 300 mg 71335-3154-01 Bryant 30 tablets — AB FDA listed —
Allopurinol 300 mg 55154-0282-00 Cardinal 10 tablets — AB FDA listed —
Allopurinol 300 mg 53401-0025-60 Aphena 90 tablets — AB FDA listed —
Allopurinol 300 mg 72789-0593-90 PD-Rx 90 tablets — AB 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

🏛️
1987
On the market since
Jan 1987
📍
2026
Currently FDA-listed
39 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.

📊 Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Allopurinol — the program that covers self-administered drugs. 19 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Allopurinol. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$25.19M
Claims incl. refills
2.4M
Beneficiaries
1.9M
Spend / beneficiary
$13.47
Spend / claim
$10.36
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

🔬 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 Allopurinol — the ingredient across all brands.

Top reported reactions

Diarrhoea8,726
Fatigue8,284
Dyspnoea7,956
Nausea7,333
Death6,902
Acute Kidney Injury6,761
Pyrexia6,124

Reporter sex

0 reports

Serious outcomes

Death21,968
Disabling4,384
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 13,180 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
71205-0377-30 30 TABLET in 1 BOTTLE, PLASTIC (71205-377-30) 2019-12-26 Active
71205-0377-60 60 TABLET in 1 BOTTLE, PLASTIC (71205-377-60) 2019-12-26 Active
71205-0377-90 You're viewing this 90 TABLET in 1 BOTTLE, PLASTIC (71205-377-90) 2019-12-26 Active

You're viewing the largest of 3 pack sizes for this product.

Pack size FAQ

What quantity is in NDC 71205-0377-90?
NDC 71205-0377-90 is a 90-count package — 90 tablet in 1 bottle, plastic.
What is the difference between NDC 71205-0377-90 and NDC 71205-0377-30?
Both are Allopurinol 300 mg Tablet — the drug itself is identical. NDC 71205-0377-90 is the 90-count package, while NDC 71205-0377-30 is the 30 tablets package.
What NDC number is used to bill for this package of Allopurinol 300 mg Tablet?
Bill NDC 71205-0377-90 — the 11-digit billing format is 71205037790. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

🧭 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) — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is 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 71205-377-90, 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: 71205-0377-90, written without dashes as 71205037790. 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 71205-0377-90, the first segment (71205) is the labeler code FDA assigned to Proficient Rx LP; the middle segment (0377) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (90) 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 Proficient Rx LP. 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 30 tablets (71205-0377-30), 60 tablets (71205-0377-60). 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?
Proficient Rx LP 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 🔄 Drug / Laboratory Test Interactions 🤰 Pregnancy 🧒 Pediatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 📦 How Supplied / Storage and Handling 📦 Storage and Handling 📋 Description 💬 Information for Patients
🎯 Indications and Usage 183 words ▾

INDICATIONS AND USAGE THIS IS NOT AN INNOCUOUS DRUG. IT IS NOT RECOMMENDED FOR THE TREATMENT OF ASYMPTOMATIC HYPERURICEMIA. Allopurinol reduces serum and urinary uric acid concentrations.

Its use should be individualized for each patient and requires an understanding of its mode of action and pharmacokinetics (see CLINICAL PHARMACOLOGY , CONTRAINDICATIONS , WARNINGS , and PRECAUTIONS ). Allopurinol is indicated in: 1. the management of patients with signs and symptoms of primary or secondary gout (acute attacks, tophi, joint destruction, uric acid lithiasis and/or nephropathy). 2. the management of patients with leukemia, lymphoma and malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels.

Treatment with allopurinol should be discontinued when the potential for overproduction of uric acid is no longer present. 3. the management of patients with recurrent calcium oxalate calculi whose daily uric acid excretion exceeds 800 mg/day in male patients and 750 mg/day in female patients. Therapy in such patients should be carefully assessed initially and reassessed periodically to determine in each case that treatment is beneficial and that the benefits outweigh the risks.

⏱️ Dosage and Administration ~3 min read ▾

DOSAGE AND ADMINISTRATION The dosage of allopurinol to accomplish full control of gout and to lower serum uric acid to normal or near-normal levels varies with the severity of the disease. The average is 200 to 300 mg/day for patients with mild gout and 400 to 600 mg/day for those with moderately severe tophaceous gout. The appropriate dosage may be administered in divided doses or as a single equivalent dose with the 300-mg tablet.

Dosage requirements in excess of 300 mg should be administered in divided doses. The minimal effective dosage is 100 to 200 mg daily and the maximal recommended dosage is 800 mg daily. To reduce the possibility of flare-up of acute gouty attacks, it is recommended that the patient start with a low dose of allopurinol (100 mg daily) and increase at weekly intervals by 100 mg until a serum uric acid level of 6 mg/dL or less is attained but without exceeding the maximal recommended dosage.

Normal serum urate levels are usually achieved in 1 to 3 weeks. The upper limit of normal is about 7 mg/dL for men and postmenopausal women and 6 mg/dL for premenopausal women. Too much reliance should not be placed on a single serum uric acid determination since, for technical reasons, estimation of uric acid may be difficult.

By selecting the appropriate dosage and, in certain patients, using uricosuric agents concurrently, it is possible to reduce serum uric acid to normal or, if desired, to as low as 2 to 3 mg/dL and keep it there indefinitely. While adjusting the dosage of allopurinol in patients who are being treated with colchicine and/or anti-inflammatory agents, it is wise to continue the latter therapy until serum uric acid has been normalized and there has been freedom from acute gouty attacks for several months. In transferring a patient from a uricosuric agent to allopurinol, the dose of the uricosuric agent should be gradually reduced over a period of several weeks and the dose of allopurinol gradually increased to the required dose needed to maintain a normal serum uric acid level.

It should also be noted that allopurinol is generally better tolerated if taken following meals. A fluid intake sufficient to yield a daily urinary output of at least 2 liters and the maintenance of a neutral or, preferably, slightly alkaline urine are desirable. Since allopurinol and its metabolites are primarily eliminated only by the kidney, accumulation of the drug can occur in renal failure, and the dose of allopurinol should consequently be reduced.

With a creatinine clearance of 10 to 20 mL/min, a daily dosage of 200 mg of allopurinol is suitable. When the creatinine clearance is less than 10 mL/min, the daily dosage should not exceed 100 mg. With extreme renal impairment (creatinine clearance less than 3 mL/min) the interval between doses may also need to be lengthened.

The correct size and frequency of dosage for maintaining the serum uric acid just within the normal range is best determined by using the serum uric acid level as an index. For the prevention of uric acid nephropathy during the vigorous therapy of neoplastic disease, treatment with 600 to 800 mg daily for 2 or 3 days is advisable together with a high fluid intake. Otherwise similar considerations to the above recommendations for treating patients with gout govern the regulation of dosage for maintenance purposes in secondary hyperuricemia.

The dose of allopurinol recommended for management of recurrent calcium oxalate stones in hyperuricosuric patients is 200 to 300 mg/day in divided doses or as the single equivalent. This dose may be adjusted up or down depending upon the resultant control of the hyperuricosuria based upon subsequent 24 hour urinary urate determinations. Clinical experience suggests that patients with recurrent calcium oxalate stones may also benefit from dietary changes such as the reduction of animal protein, sodium, refined sugars, oxalate-rich foods, and excessive calcium intake, as well as an increase in oral fluids and dietary…

⛔ Contraindications 17 words ▾

CONTRAINDICATIONS Patients who have developed a severe reaction to allopurinol should not be restarted on the drug.

⚠️ Warnings ~1 min read ▾

WARNINGS ALLOPURINOL SHOULD BE DISCONTINUED AT THE FIRST APPEARANCE OF SKIN RASH OR OTHER SIGNS WHICH MAY INDICATE AN ALLERGIC REACTION. In some instances a skin rash may be followed by more severe hypersensitivity reactions such as exfoliative, urticarial and purpuric lesions, as well as Stevens-Johnson syndrome (erythema multiforme exudativum), Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) and/or generalized vasculitis, irreversible hepatotoxicity, and, on rare occasions, death (see ADVERSE REACTIONS ).

In patients receiving mercaptopurine or azathioprine, the concomitant administration of 300 to 600 mg of allopurinol per day will require a reduction in dose to approximately one-third to one-fourth of the usual dose of mercaptopurine or azathioprine. Subsequent adjustment of doses of mercaptopurine or azathioprine should be made on the basis of therapeutic response and the appearance of toxic effects (see CLINICAL PHARMACOLOGY ). A few cases of reversible clinical hepatotoxicity have been noted in patients taking allopurinol, and in some patients, asymptomatic rises in serum alkaline phosphatase or serum transaminase have been observed.

If anorexia, weight loss, or pruritus develop in patients on allopurinol, evaluation of liver function should be part of their diagnostic workup. In patients with pre-existing liver disease, periodic liver function tests are recommended during the early stages of therapy. Due to the occasional occurrence of drowsiness, patients should be alerted to the need for due precaution when engaging in activities where alertness is mandatory.

The occurrence of hypersensitivity reactions to allopurinol may be increased in patients with decreased renal function receiving thiazides and allopurinol concurrently. For this reason, in this clinical setting, such combinations should be administered with caution and patients should be observed closely.

🤒 Adverse Reactions ~3 min read ▾

ADVERSE REACTIONS Data upon which the following estimates of incidence of adverse reactions are made are derived from experiences reported in the literature, unpublished clinical trials and voluntary reports since marketing of allopurinol began. Past experience suggested that the most frequent event following the initiation of allopurinol treatment was an increase in acute attacks of gout (average 6% in early studies). An analysis of current usage suggests that the incidence of acute gouty attacks has diminished to less than 1%.

The explanation for this decrease has not been determined but may be due in part to initiating therapy more gradually (see PRECAUTIONS and DOSAGE AND ADMINISTRATION ). The most frequent adverse reaction to allopurinol is skin rash. Skin reactions can be severe and sometimes fatal.

Therefore, treatment with allopurinol should be discontinued immediately if a rash develops (see Error! Hyperlink reference not valid. ). Some patients with the most severe reaction also had fever, chills, arthralgias, cholestatic jaundice, eosinophilia and mild leukocytosis or leukopenia.

Among 55 patients with gout treated with allopurinol for 3 to 34 months (average greater than 1 year) and followed prospectively, Rundles observed that 3% of patients developed a type of drug reaction which was predominantly a pruritic maculopapular skin eruption, sometimes scaly or exfoliative. However, with current usage, skin reactions have been observed less frequently than 1%. The explanation for this decrease is not obvious.

The incidence of skin rash may be increased in the presence of renal insufficiency. The frequency of skin rash among patients receiving ampicillin or amoxicillin concurrently with allopurinol has been reported to be increased (see PRECAUTIONS ). Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome or drug hypersensitivity syndrome (DHS) has been reported in association with allopurinol use.

The syndrome includes many of the severe reactions described above, and is potentially life-threatening and fatal. The syndrome is often characterized by fever, severe and profuse skin rash, elevated leukocyte counts and in particular, elevated eosinophil counts, lymphadenopathy, and multi-organ pathologies. Systemic symptoms often included, but were not limited to, the hepatic and renal systems.

Symptoms involving the cardiac, gastrointestinal, lymphatic, pulmonary, and ophthalmic systems were also reported as occurring as part of the syndrome. It has been reported that symptoms may develop in approximately 1 week from initiating allopurinol therapy, but longer latency periods have also been reported. To report SUSPECTED ADVERSE REACTIONS, contact Sun Pharmaceutical Industries, Inc. at 1-800-406-7984 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Most Common Reactions Early clinical studies and incidence rates from early clinical experience with allopurinol suggested that these adverse reactions were found to occur at a rate of greater than 1%. The most frequent event observed was acute attacks of gout following the initiation of therapy. Analyses of current usage suggest that the incidence of these adverse reactions is now less than 1%.

The explanation for this decrease has not been determined, but it may be due to following recommended usage (see ADVERSE REACTIONS introduction, INDICATIONS AND USAGE , PRECAUTIONS , and DOSAGE AND ADMINISTRATION ). Probably Causally Related: Gastrointestinal: Diarrhea, nausea, alkaline phosphatase increase, SGOT/SGPT increase. Metabolic and Nutritional: Acute attacks of gout.

Skin and Appendages: Rash, maculopapular rash. Incidence Less Than 1% Probably Causally Related: Body As a Whole: Ecchymosis, fever, headache. Cardiovascular: Necrotizing angiitis, vasculitis.

Gastrointestinal: Hepatic necrosis, granulomatous hepatitis, hepatomegaly, hyperbilirubinemia, cholestatic jaundice, vomiting, intermittent abdominal pain, gastritis, dyspepsia. Hemic and Lymphatic: Thrombocytopeni…

🔄 Drug Interactions ~3 min read ▾

Drug Interactions In patients receiving mercaptopurine or azathioprine, the concomitant administration of 300 to 600 mg of allopurinol per day will require a reduction in dose to approximately one third to one fourth of the usual dose of mercaptopurine or azathioprine. Subsequent adjustment of doses of mercaptopurine or azathioprine should be made on the basis of therapeutic response and the appearance of toxic effects (see CLINICAL PHARMACOLOGY ). It has been reported that allopurinol prolongs the half-life of the anticoagulant, dicumarol.

The clinical basis of this drug interaction has not been established but should be noted when allopurinol is given to patients already on dicumarol therapy. Since the excretion of oxipurinol is similar to that of urate, uricosuric agents, which increase the excretion of urate, are also likely to increase the excretion of oxipurinol and thus lower the degree of inhibition of xanthine oxidase. The concomitant administration of uricosuric agents and allopurinol has been associated with a decrease in the excretion of oxypurines (hypoxanthine and xanthine) and an increase in urinary uric acid excretion compared with that observed with allopurinol alone.

Although clinical evidence to date has not demonstrated renal precipitation of oxypurines in patients either on allopurinol alone or in combination with uricosuric agents, the possibility should be kept in mind. The reports that the concomitant use of allopurinol and thiazide diuretics may contribute to the enhancement of allopurinol toxicity in some patients have been reviewed in an attempt to establish a cause-and-effect relationship and a mechanism of causation. Review of these case reports indicates that the patients were mainly receiving thiazide diuretics for hypertension and that tests to rule out decreased renal function secondary to hypertensive nephropathy were not often performed.

In those patients in whom renal insufficiency was documented, however, the recommendation to lower the dose of allopurinol was not followed. Although a causal mechanism and a cause-and-effect relationship have not been established, current evidence suggests that renal function should be monitored in patients on thiazide diuretics and allopurinol even in the absence of renal failure, and dosage levels should be even more conservatively adjusted in those patients on such combined therapy if diminished renal function is detected.

An increase in the frequency of skin rash has been reported among patients receiving ampicillin or amoxicillin concurrently with allopurinol compared to patients who are not receiving both drugs. The cause of the reported association has not been established. Enhanced bone marrow suppression by cyclophosphamide and other cytotoxic agents has been reported among patients with neoplastic disease, except leukemia, in the presence of allopurinol.

However, in a well-controlled study of patients with lymphoma on combination therapy, allopurinol did not increase the marrow toxicity of patients treated with cyclophosphamide, doxorubicin, bleomycin, procarbazine and/or mechlorethamine. Tolbutamide's conversion to inactive metabolites has been shown to be catalyzed by xanthine oxidase from rat liver. The clinical significance, if any, of these observations is unknown.

Chlorpropamide's plasma half-life may be prolonged by allopurinol, since allopurinol and chlorpropamide may compete for excretion in the renal tubule. The risk of hypoglycemia secondary to this mechanism may be increased if allopurinol and chlorpropamide are given concomitantly in the presence of renal insufficiency. Rare reports indicate that cyclosporine levels may be increased during concomitant treatment with allopurinol.

Monitoring of cyclosporine levels and possible adjustment of cyclosporine dosage should be considered when these drugs are co-administered.

🔄 Drug / Laboratory Test Interactions 14 words ▾

Drug/Laboratory Test Interactions Allopurinol is not known to alter the accuracy of laboratory tests.

🤰 Pregnancy ~1 min read ▾

Pregnancy Teratogenic Effects Reproductive studies have been performed in rats and rabbits at doses up to twenty times the usual human dose (5 mg/kg per day), and it was concluded that there was no impaired fertility or harm to the fetus due to allopurinol. There is a published report of a study in pregnant mice given 50 or 100 mg/kg allopurinol intraperitoneally on gestation days 10 or 13. There were increased numbers of dead fetuses in dams given 100 mg/kg allopurinol but not in those given 50 mg/kg.

There were increased numbers of external malformations in fetuses at both doses of allopurinol on gestation day 10 and increased numbers of skeletal malformations in fetuses at both doses on gestation day 13. It cannot be determined whether this represented a fetal effect or an effect secondary to maternal toxicity. There are, however, no adequate or 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. Experience with allopurinol during human pregnancy has been limited partly because women of reproductive age rarely require treatment with allopurinol. However, in 2011, a literature publication case report describes the outcome of a full term pregnancy in a 35 year-old woman who had recurrent kidney stones since age 18 who took allopurinol throughout the pregnancy.

The child had multiple complex birth defects and died at 8 days of life. A second report in 2013 (Hoeltzenbein M et al (2013); PLoS ONE 8(6): e66637), provided data on 31 prospectively ascertained pregnancies involving mothers exposed to allopurinol for varying durations during the first trimester. The overall rate of major fetal malformations and spontaneous abortions was reported to be within the normal expected range; however, one child had severe malformations similar to those described in the cited earlier case report.

🧒 Pediatric Use 38 words ▾

Pediatric Use Allopurinol is rarely indicated for use in children with the exception of those with hyperuricemia secondary to malignancy or to certain rare inborn errors of purine metabolism (see INDICATIONS AND USAGE and DOSAGE AND ADMINISTRATION ).

🆘 Overdosage 128 words ▾

OVERDOSAGE Massive overdosing or acute poisoning by allopurinol has not been reported. In mice, the 50% lethal dose (LD 50 ) is 160 mg/kg given intraperitoneally (IP) with deaths delayed up to 5 days and 700 mg/kg orally (PO) (approximately 140 times the usual human dose) with deaths delayed up to 3 days. In rats, the acute LD 50 is 750 mg/kg IP and 6000 mg/kg PO (approximately 1200 times the human dose).

In the management of overdosage there is no specific antidote for allopurinol. There has been no clinical experience in the management of a patient who has taken massive amounts of allopurinol. Both allopurinol and oxipurinol are dialyzable; however, the usefulness of hemodialysis or peritoneal dialysis in the management of an overdose of allopurinol is unknown.

🧬 Clinical Pharmacology ~3 min read ▾

CLINICAL PHARMACOLOGY Allopurinol acts on purine catabolism, without disrupting the biosynthesis of purines. It reduces the production of uric acid by inhibiting the biochemical reactions immediately preceding its formation. Allopurinol is a structural analogue of the natural purine base, hypoxanthine.

It is an inhibitor of xanthine oxidase, the enzyme responsible for the conversion of hypoxanthine to xanthine and of xanthine to uric acid, the end product of purine metabolism in man. Allopurinol is metabolized to the corresponding xanthine analogue, oxipurinol (alloxanthine), which also is an inhibitor of xanthine oxidase. It has been shown that reutilization of both hypoxanthine and xanthine for nucleotide and nucleic acid synthesis is markedly enhanced when their oxidations are inhibited by allopurinol and oxipurinol.

This reutilization does not disrupt normal nucleic acid anabolism, however, because feedback inhibition is an integral part of purine biosynthesis. As a result of xanthine oxidase inhibition, the serum concentration of hypoxanthine plus xanthine in patients receiving allopurinol for treatment of hyperuricemia is usually in the range of 0.3 to 0.4 mg/dL compared to a normal level of approximately 0.15 mg/dL. A maximum of 0.9 mg/dL of these oxypurines has been reported when the serum urate was lowered to less than 2 mg/dL by high doses of allopurinol.

These values are far below the saturation levels at which point their precipitation would be expected to occur (above 7 mg/dL). The renal clearance of hypoxanthine and xanthine is at least 10 times greater than that of uric acid. The increased xanthine and hypoxanthine in the urine have not been accompanied by problems of nephrolithiasis.

Xanthine crystalluria has been reported in only three patients. Two of the patients had Lesch-Nyhan syndrome, which is characterized by excessive uric acid production combined with a deficiency of the enzyme, hypoxanthineguanine phosphoribosyltransferase (HGPRTase). This enzyme is required for the conversion of hypoxanthine, xanthine, and guanine to their respective nucleotides.

The third patient had lymphosarcoma and produced an extremely large amount of uric acid because of rapid cell lysis during chemotherapy. Allopurinol is approximately 90% absorbed from the gastrointestinal tract. Peak plasma levels generally occur at 1.5 hours and 4.5 hours for allopurinol and oxipurinol respectively, and after a single oral dose of 300 mg allopurinol, maximum plasma levels of about 3 mcg/mL of allopurinol and 6.5 mcg/mL of oxipurinol are produced.

Approximately 20% of the ingested allopurinol is excreted in the feces. Because of its rapid oxidation to oxipurinol and a renal clearance rate approximately that of glomerular filtration rate, allopurinol has a plasma half-life of about 1 to 2 hours. Oxipurinol, however, has a longer plasma half-life (approximately 15 hours) and therefore effective xanthine oxidase inhibition is maintained over a 24-hour period with single daily doses of allopurinol.

Whereas allopurinol is cleared essentially by glomerular filtration, oxipurinol is reabsorbed in the kidney tubules in a manner similar to the reabsorption of uric acid. The clearance of oxipurinol is increased by uricosuric drugs, and as a consequence, the addition of a uricosuric agent reduces to some degree the inhibition of xanthine oxidase by oxipurinol and increases to some degree the urinary excretion of uric acid. In practice, the net effect of such combined therapy may be useful in some patients in achieving minimum serum uric acid levels provided the total urinary uric acid load does not exceed the competence or the patient's renal function.

Hyperuricemia may be primary, as in gout, or secondary to diseases such as acute and chronic leukemia, polycythemia vera, multiple myeloma, and psoriasis. It may occur with the use of diuretic agents, during renal dialysis, in the presence of renal damage, during starvation or reducing diets, and in the…

📦 How Supplied / Storage and Handling 74 words ▾

HOW SUPPLIED Allopurinol tablets, USP are supplied as follows: Allopurinol tablets, 300 mg round, orange, scored, debossed MP 80 Bottles of 30 NDC 71205-377-30 Bottles of 60 NDC 71205-377-60 Bottles of 90 NDC 71205-377-90 Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature] DISPENSE IN TIGHT, LIGHT-RESISTANT CONTAINER. Distributed by: Sun Pharmaceutical Industries, Inc. Cranbury, NJ 08512 Repackaged by: Proficient Rx LP Thousand Oaks, CA 91320 Rev 04, December 2018

📦 Storage and Handling 40 words ▾

Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature] DISPENSE IN TIGHT, LIGHT-RESISTANT CONTAINER. Distributed by: Sun Pharmaceutical Industries, Inc. Cranbury, NJ 08512 Repackaged by: Proficient Rx LP Thousand Oaks, CA 91320 Rev 04, December 2018

📋 Description 64 words ▾

DESCRIPTION Allopurinol has the following structural formula: Allopurinol is known chemically as 1,5-dihydro-4 H -pyrazolo [3,4- d ]pyrimidin-4-one. It is a xanthine oxidase inhibitor which is administered orally. Inactive Ingredients: corn starch, croscarmellose sodium, lactose, magnesium stearate, povidone. Allopurinol 300 mg also contains FD&C yellow #6 lake. Its solubility in water at 37°C is 80.0 mg/dL and is greater in an alkaline solution. structure

💬 Information for Patients 178 words ▾

Information for Patients Patients should be informed of the following: (1) They should be cautioned to discontinue allopurinol and to consult their physician immediately at the first sign of a skin rash, painful urination, blood in the urine, irritation of the eyes, or swelling of the lips or mouth. (2) They should be reminded to continue drug therapy prescribed for gouty attacks since optimal benefit of allopurinol may be delayed for 2 to 6 weeks. (3) They should be encouraged to increase fluid intake during therapy to prevent renal stones.

(4) If a single dose of allopurinol is occasionally forgotten, there is no need to double the dose at the next scheduled time. (5) There may be certain risks associated with the concomitant use of allopurinol and dicumarol, sulfinpyrazone, mercaptopurine, azathioprine, ampicillin, amoxicillin, and thiazide diuretics, and they should follow the instructions of their physician. (6) Due to the occasional occurrence of drowsiness, patients should take precautions when engaging in activities where alertness is mandatory.

(7) Patients may wish to take allopurinol after meals to minimize gastric irritation.

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