Nitrofurantoin Macrocrystals 50 mg Capsule, 100-count — NDC 00115-1643-01 package photo

Nitrofurantoin Macrocrystals 50 mg Capsule, 100-count

by Amneal Pharmaceuticals of New York LLC · 100 CAPSULE in 1 BOTTLE (0115-1643-01)
NDC 00115-1643-01
🏷️ FDA NDC (as labeled) 0115-1643-01 billing pads the labeler segment with a zero
This package
Contains100-count Cost per ea$0.1587 NADAC Per package$15.87 / 100 capsules Pack sizes2 compare ↓
Also priced by: Medicaid pays $0.4668/unit · Part D plans $0.3581/unit — full pricing hub ↓
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) 0115-1643-01
Product NDC 0115-1643
11-digit billing NDC 00115164301
NCPDP billing unit EA — each (per item)
RxCUI 311995, 1648759
UNII 927AH8112L
Application # ANDA073671
SPL Set ID 341c75ac-fba5-480d-a221-868c4195cb6f
Established class (EPC) Nitrofuran Antibacterial
Chemical class Nitrofurans
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2007-03-08
Route ORAL
Dosage form CAPSULE
Substance NITROFURANTOIN
GPI-14 16800050100115
GPI class Nitrofurantoin Macrocrystal
GCN Seq No 009430
GCN 41822
HICL code 004087
Ingredient (HICL) Nitrofurantoin Macrocrystal
HIC1 code W
Therapeutic class — broad (HIC1) Anti-Infecting Agents
HIC2 code W2
Therapeutic class — intermediate (HIC2) Antibacterials
HIC3 code W2F
Therapeutic class — specific (HIC3) Nitrofuran Derivatives Antibacterial Agents
AHFS code 08:36.00.00
AHFS class Urinary Anti-Infectives
FDB label name NITROFURANTOIN MCR 50 MG CAP
FDB brand name Nitrofurantoin
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 0115-1643-01 — a 4-4-2 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 labeler segment → 00115-1643-01. 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 Nitrofuran Antibacterial class.

Pharmacologic class Nitrofuran Antibacterial
Drug family (ATC) Nitrofuran 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

LabelerAmneal Pharmaceuticals of New York LLC
Application holderIMPAX LABORATORIES INC
FDA applicationANDA073671 (ANDA)
Labeler code00115
First marketedMar 2007
Product typeHuman Prescription Drug
Portfolio228 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 NITROFURANTOIN MCR 50 MG CAP Ingredient Nitrofurantoin Macrocrystal
📗 Our plain-language guide HelloPharmacist
  • Yes, nitrofurantoin is used specifically for urinary tract infections — typically bladder infections caused by certain bacteria. It's not used for kidney infections or for infectio...
  • What exactly is nitrofurantoin used for — is it just for bladder infections?
  • Taking it with food genuinely makes a difference — it helps your body absorb the medication better and also reduces the chances of an upset stomach or nausea, which are the most co...
  • Do I really have to take it with food? What if I forget?
📖 Read our full Nitrofurantoin 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 pink / white
ShapeCapsule
ImprintZ;Zenith;100mg;2131
Size18 mm
ScoringNot scored
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.

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

  • UNII LMI26O6933
    Alumina is a white powder form of aluminum oxide. It's used as a filler to add bulk to tablets and capsules, and sometimes as a thickening or anti-caking agent in powdered formulations.
  • UNII 9DBA0SBB0L
    A synthetic red dye derived from coal tar used as a colorant in medicines and cosmetics. It gives tablets, capsules, and liquids their red or pink appearance for identification and visual appeal.
  • UNII 35SW5USQ3G
    A synthetic yellow dye used to color medicines. It helps make tablets, capsules, and liquids visually distinct so patients can easily identify their medication.
  • UNII H3R47K3TBD
    FD&C Blue No. 1 is a synthetic blue dye approved for use in foods and medicines. It serves as a colorant to give the medication its distinctive appearance and help with product identification.
  • UNII L06K8R7DQK
    A synthetic blue dye approved by the FDA for use in medications and foods. It serves as a colorant to make pills and liquids visually distinct and easier to identify.
  • UNII WZB9127XOA
    A synthetic red dye used to color medications and make them easier to identify. It serves as a colorant in tablets, capsules, and liquid formulations.
  • UNII XM0M87F357
    A dark iron oxide compound that gives medicines their black or dark color. It's used as a colorant in tablets and capsules to help identify the product and make it visually distinctive.
  • UNII 2G86QN327L
    Gelatin is a protein derived from animal collagen, commonly used in medicines as a gelling agent and capsule material. It helps create soft or hard capsule shells that hold and release medication, and can also thicken liquid formulations.
  • UNII D3741U8K7L
    A blue colorant derived from indigo dye. It's added to tablets and capsules to provide color identification and improve the appearance of the medication.
  • UNII EWQ57Q8I5X
    Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
  • 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.
  • UNII 46N107B71O
    Shellac is a natural resin secreted by the lac beetle. It's used as a coating on tablets and capsules to control how quickly the medicine dissolves and to improve appearance and stability.
  • UNII O8232NY3SJ
    A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
  • UNII 7SEV7J4R1U
    A powder made from a naturally occurring mineral. In medicines, talc works as a glidant and anti-caking agent, helping tablets and capsules flow smoothly during manufacturing and preventing clumping.
  • UNII 15FIX9V2JP
    Titanium dioxide is a bright white mineral powder commonly used as a colorant and opacifying agent. It makes pills and tablets white or lighter in color and helps make coatings non-transparent.

15 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 eaPer package
Retail pharmacies payNADAC · weekly $0.159 $15.87 / 100 capsules
Medicaid paysCMS SDUD · 12 mo $0.4668 $46.68 / 100 capsules
Medicare drug plans payPart D · Q2 2026 $0.3581 $35.81 / 100 capsules
NADAC price history (per ea) — tap or hover for the price & month
Dec 2021 Jul 2022 Dec 2025 Aug 2026 $0.425 $0.140
▼ Down 60% over the last 24 months.
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
Nitrofurantoin macrocrystals 50 mg 43386-0641-01 Lupin 100 capsules $0.153 AB Availability likely save 4%
Nitrofurantoin Macrocrystals 50 mgthis 00115-1643-01 Amneal 100 capsules $0.159 AB Availability likely
nitrofurantoin macrocrystals 50 mg 00904-7026-61 Major 100 capsules $0.159 AB Availability likely
Nitrofurantoin Macrocrystals 50 mg 50268-0623-15 AvPAK 50 capsules $0.159 AB Availability likely
nitrofurantoin (macrocrystals) 50 mg 59651-0753-01 Aurobindo 100 capsules $0.159 AB Availability likely
Nitrofurantoin Macrocrystals 50 mg 60687-0839-01 American 100 capsules $0.159 AB Availability likely
Nitrofurantoin 50 mg 62332-0390-31 Alembic 100 capsules $0.159 AB Availability likely
nitrofurantoin macrocrystals 50 mg 68001-0604-00 BluePoint 100 capsules $0.159 AB Availability likely
nitrofurantoin macrocrystals 50 mg 68382-0559-01 Zydus 100 capsules $0.159 AB Availability likely
nitrofurantoin macrocrystals 50 mg 70756-0411-11 Lifestar 100 capsules $0.159 AB Availability likely
nitrofurantoin macrocrystals 50 mg 72603-0183-01 NorthStar 100 capsules $0.159 AB Availability likely
nitrofurantoin macrocrystals 50 mg 47781-0307-01 Alvogen 100 capsules $0.310 AB Discontinued +95%
Nitrofurantion 50 mg 68001-0385-00 BluePoint 100 capsules $0.310 FDA listed +95%
Nitrofurantoin 50 mg 46708-0390-31 Alembic 100 capsules AB FDA listed
Macrodantin 50 mg 52427-0287-01 Almatica 100 capsules AB Discontinued
Nitrofurantion 50 mg 57664-0232-18 Sun 1000 capsules FDA listed
nitrofurantoin macrocrystals 50 mg 70771-1170-00 Zydus 1000 capsules AB FDA listed
Nitrofurantion Macrocrystals 50 mg 71205-0023-10 Proficient 10 capsules AB FDA listed
nitrofurantoin macrocrystals 50 mg 71335-2254-01 Bryant 28 capsules 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

🏛️
2007
On the market since
Mar 2007
📍
2026
Currently FDA-listed
19 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.

🗺️ Medicaid utilization & spend

📍 This exact package only: Medicaid data is reported per full 11-digit NDC — labeler, product and pack size — so every number here is for 00115-1643-01, not the drug overall. Other pack sizes report separately.
💊 Pharmacy benefit only: These are Medicaid outpatient pharmacy claims, billed by NDC. They exclude the medical benefit — clinic- or hospital-administered drugs billed under HCPCS J-codes — so drugs used mostly that way (e.g. Avastin, Lucentis, Keytruda) can look low or missing here. That’s expected, not an error.
📅 Q1 2025 – Q4 2025 · 4 quarters of data
ⓘ The newest quarter is usually incomplete when first published; states restate recent quarters in later CMS releases, so the latest figures typically revise upward. State coverage-policy changes can also shift quarter-to-quarter totals.
Prescriptions last 4 qtrs
9.9K
Units reimbursed last 4 qtrs
322.7K
Gross reimbursed last 4 qtrs
$150.6K
Avg / prescription
$15.22
Avg / unit
$0.4668
Latest quarter Q4 2025
2KRx
Medicaid pays / ea
$0.4668
gross reimbursed
vs
NADAC / ea
$0.1587
acquisition cost
=
Spread
+$0.3081
+194% vs cost
What Medicaid paid per ea (before rebates; includes the pharmacy’s dispensing fee) compared with NADAC — the average price pharmacies pay to buy the drug. A positive spread means Medicaid reimbursed more than the purchase price, before manufacturer rebates.
Fee-for-service vs managed care
47% FFS 53% MCO
Fee-for-service · 4,666 Rx Managed care · 5,232 Rx
State Medicaid map
Alaska: 800 units · 109 per 100k residents AK Maine: 2,103 units · 151 per 100k residents ME Washington: 7,400 units · 94.7 per 100k residents WA Idaho: 2,855 units · 145 per 100k residents ID Montana: no data reported MT North Dakota: no data reported ND Minnesota: 6,959 units · 121 per 100k residents MN Wisconsin: 16,022 units · 271 per 100k residents WI Michigan: 11,145 units · 111 per 100k residents MI New York: 12,277 units · 62.7 per 100k residents NY Vermont: 780 units · 121 per 100k residents VT New Hampshire: no data reported NH Oregon: 12,927 units · 305 per 100k residents OR Nevada: 5,171 units · 162 per 100k residents NV Wyoming: no data reported WY South Dakota: no data reported SD Iowa: 3,223 units · 100 per 100k residents IA Illinois: 15,538 units · 124 per 100k residents IL Indiana: 5,963 units · 86.9 per 100k residents IN Ohio: 13,797 units · 117 per 100k residents OH Pennsylvania: 3,251 units · 25.1 per 100k residents PA New Jersey: 4,625 units · 49.8 per 100k residents NJ Massachusetts: 4,445 units · 63.5 per 100k residents MA California: 58,597 units · 150 per 100k residents CA Utah: 1,197 units · 35.0 per 100k residents UT Colorado: 8,742 units · 149 per 100k residents CO Nebraska: 3,364 units · 170 per 100k residents NE Missouri: 5,928 units · 95.7 per 100k residents MO Kentucky: 10,376 units · 229 per 100k residents KY West Virginia: 4,269 units · 241 per 100k residents WV Virginia: 6,573 units · 75.4 per 100k residents VA Maryland: 4,760 units · 77.0 per 100k residents MD Connecticut: 4,588 units · 127 per 100k residents CT Rhode Island: no data reported RI Arizona: 10,779 units · 145 per 100k residents AZ New Mexico: 5,498 units · 260 per 100k residents NM Kansas: 3,421 units · 116 per 100k residents KS Arkansas: no data reported AR Tennessee: 17,536 units · 246 per 100k residents TN North Carolina: 10,150 units · 93.7 per 100k residents NC South Carolina: 324 units · 6.0 per 100k residents SC Delaware: no data reported DE Oklahoma: 5,550 units · 137 per 100k residents OK Louisiana: 6,944 units · 152 per 100k residents LA Mississippi: 2,504 units · 85.2 per 100k residents MS Alabama: 6,755 units · 132 per 100k residents AL Georgia: 2,831 units · 25.7 per 100k residents GA D.C.: no data reported DC Hawaii: no data reported HI Texas: 9,498 units · 31.1 per 100k residents TX Florida: 3,225 units · 14.3 per 100k residents FL
Units reimbursed · per 100k residents
6.0305
gray = no data reported
Colors are per 100,000 residents, so big states don’t automatically dominate. Tap or hover a state for its actual totals.
Tap or hover a state
…for its Medicaid breakdown
🏆 Top states by units · per 100k residents
1 Oregon 305 /100k
2 Wisconsin 271 /100k
3 New Mexico 260 /100k
4 Tennessee 246 /100k
5 West Virginia 241 /100k
6 Kentucky 229 /100k
7 Nebraska 170 /100k
8 Nevada 162 /100k
National units — by quarter
💵 About the dollar figures: “reimbursed” is what Medicaid paid pharmacies before confidential manufacturer rebates, so the program’s real net cost is lower than these numbers. Fee-for-service and managed-care claims are combined unless split above. Source: CMS State Drug Utilization Data; per-100k rates use 2023 Census population estimates.

💊 Medicaid utilization by pack size

Medicaid (SDUD) totals over the four most recent reported quarters for every package size of this drug — handy when a specific package (e.g. a starter/titration pack) carries little or no Medicaid volume on its own.
1000 capsules00115-1643-03 No Medicaid data
Drug total (last 4 qtrs): 9,898 Rx · 322,690 units · $150,631 gross reimbursed
Tap a pack size to open its page. Source: CMS State Drug Utilization Data, last 4 quarters.

📦 Packaging — all sizes for this product

Package NDCDescription Per unit Per pack Marketing startStatus
00115-1643-01 You're viewing this 100 CAPSULE in 1 BOTTLE (0115-1643-01) $0.1587 / ea $15.87 2007-03-08 Active
00115-1643-03 1000 CAPSULE in 1 BOTTLE (0115-1643-03) 2007-03-08 Active

You're viewing the smallest of 2 pack sizes for this product.

In Medicaid, this is the most-dispensed pack of this product — about 100% of fills over the last four reported quarters. See all packs ↓

Pack size FAQ

What quantity is in NDC 00115-1643-01?
NDC 00115-1643-01 is a 100-count package — 100 capsule in 1 bottle.
What is the difference between NDC 00115-1643-01 and NDC 00115-1643-03?
Both are Nitrofurantoin Macrocrystals 50 mg Capsule — the drug itself is identical. NDC 00115-1643-01 is the 100-count package, while NDC 00115-1643-03 is the 1000 capsules package.
What NDC number is used to bill for this package of Nitrofurantoin Macrocrystals 50 mg Capsule?
Bill NDC 00115-1643-01 — the 11-digit billing format is 00115164301. 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.

📄 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 ~1 min read

INDICATIONS AND USAGE Nitrofurantoin Capsules USP (Macrocrystals) are specifically indicated for the treatment of urinary tract infections when due to susceptible strains of Escherichia coli , enterococci, Staphylococcus aureus , and certain susceptible strains of Klebsiella and Enterobacter species. Nitrofurantoin is not indicated for the treatment of pyelonephritis or perinephric abscesses. To reduce the development of drug-resistant bacteria and maintain the effectiveness of Nitrofurantoin Capsules USP (Macrocrystals) and other antibacterial drugs, Nitrofurantoin Capsules USP (Macrocrystals) should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.

When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. Nitrofurantoins lack the broader tissue distribution of other therapeutic agents approved for urinary tract infections.

Consequently, many patients who are treated with Nitrofurantoin Capsules USP (Macrocrystals) are predisposed to persistence or reappearance of bacteriuria. Urine specimens for culture and susceptibility testing should be obtained before and after completion of therapy. If persistence or reappearance of bacteriuria occurs after treatment with Nitrofurantoin Capsules USP (Macrocrystals), other therapeutic agents with broader tissue distribution should be selected.

In considering the use of Nitrofurantoin Capsules USP (Macrocrystals), lower eradication rates should be balanced against the increased potential for systemic toxicity and for the development of antimicrobial resistance when agents with broader tissue distribution are utilized.

⏱️ Dosage and Administration 149 words

DOSAGE AND ADMINISTRATION Nitrofurantoin capsules (macrocrystals) should be given with food to improve drug absorption and, in some patients, tolerance. Adults 50 to 100 mg four times a day - the lower dosage level is recommended for uncomplicated urinary tract infections. Pediatric Patients 5 to 7 mg/kg of body weight per 24 hours, given in four divided doses (contraindicated under one month of age).

Therapy should be continued for one week or for at least 3 days after sterility of the urine is obtained. Continued infection indicates the need for reevaluation. For long-term suppressive therapy in adults, a reduction of dosage to 50 to 100 mg at bedtime may be adequate.

For long-term suppressive therapy in pediatric patients, doses as low as 1 mg/kg per 24 hours, given in a single dose or in two divided doses, may be adequate. SEE WARNINGS SECTION REGARDING RISKS ASSOCIATED WITH LONG-TERM THERAPY.

Contraindications 131 words

CONTRAINDICATIONS Anuria, oliguria, or significant impairment of renal function (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine) are contraindications. Treatment of this type of patient carries an increased risk of toxicity because of impaired excretion of the drug. Because of the possibility of hemolytic anemia due to immature erythrocyte enzyme systems (glutathione instability), the drug is contraindicated in pregnant patients at term (38 to 42 weeks’ gestation), during labor and delivery, or when the onset of labor is imminent.

For the same reason, the drug is contraindicated in neonates under one month of age. Nitrofurantoin capsules (macrocrystals) are contraindicated in patients with a previous history of cholestatic jaundice/hepatic dysfunction associated with nitrofurantoin. Nitrofurantoin capsules (macrocrystals) are also contraindicated in those patients with known hypersensitivity to nitrofurantoin.

⚠️ Warnings ~2 min read

WARNINGS Pulmonary Reactions ACUTE, SUBACUTE, OR CHRONIC PULMONARY REACTIONS HAVE BEEN OBSERVED IN PATIENTS TREATED WITH NITROFURANTOIN. IF THESE REACTIONS OCCUR, NITROFURANTOIN MACROCRYSTALS SHOULD BE DISCONTINUED AND APPROPRIATE MEASURES TAKEN. REPORTS HAVE CITED PULMONARY REACTIONS AS A CONTRIBUTING CAUSE OF DEATH.

CHRONIC PULMONARY REACTIONS (DIFFUSE INTERSTITIAL PNEUMONITIS OR PULMONARY FIBROSIS, OR BOTH) CAN DEVELOP INSIDIOUSLY. THESE REACTIONS OCCUR RARELY AND GENERALLY IN PATIENTS RECEIVING THERAPY FOR SIX MONTHS OR LONGER. CLOSE MONITORING OF THE PULMONARY CONDITION OF PATIENTS RECEIVING LONG-TERM THERAPY IS WARRANTED AND REQUIRES THAT THE BENEFITS OF THERAPY BE WEIGHED AGAINST POTENTIAL RISKS (SEE ADVERSE REACTIONS, Respiratory ).

Hepatotoxicity Hepatic reactions, including hepatitis, cholestatic jaundice, chronic active hepatitis, and hepatic necrosis, occur rarely. Fatalities have been reported. The onset of chronic active hepatitis may be insidious, and patients should be monitored periodically for changes in biochemical tests that would indicate liver injury.

If hepatitis occurs, the drug should be withdrawn immediately and appropriate measures should be taken. Neuropathy Peripheral neuropathy, which may become severe or irreversible, has occurred. Fatalities have been reported.

Conditions such as renal impairment (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine), anemia, diabetes mellitus, electrolyte imbalance, vitamin B deficiency, and debilitating disease may enhance the occurrence of peripheral neuropathy. Patients receiving long-term therapy should be monitored periodically for changes in renal function. Optic neuritis has been reported rarely in postmarketing experience with nitrofurantoin formulations.

Hemolytic Anemia Cases of hemolytic anemia of the primaquine-sensitivity type have been induced by nitrofurantoin. Hemolysis appears to be linked to a glucose-6-phosphate dehydrogenase deficiency in the red blood cells of the affected patients. This deficiency is found in 10 percent of Blacks and a small percentage of ethnic groups of Mediterranean and Near-Eastern origin.

Hemolysis is an indication for discontinuing nitrofurantoin macrocrystals; hemolysis ceases when the drug is withdrawn. Clostridium difficile -Associated Diarrhea Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including nitrofurantoin, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile .

C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use.

Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile , and surgical evaluation should be instituted as clinically indicated.

🤒 Adverse Reactions ~2 min read

ADVERSE REACTIONS Respiratory CHRONIC, SUBACUTE, OR ACUTE PULMONARY HYPERSENSITIVITY REACTIONS MAY OCCUR. CHRONIC PULMONARY REACTIONS OCCUR GENERALLY IN PATIENTS WHO HAVE RECEIVED CONTINUOUS TREATMENT FOR SIX MONTHS OR LONGER. MALAISE, DYSPNEA ON EXERTION, COUGH, AND ALTERED PULMONARY FUNCTION ARE COMMON MANIFESTATIONS WHICH CAN OCCUR INSIDIOUSLY.

RADIOLOGIC AND HISTOLOGIC FINDINGS OF DIFFUSE INTERSTITIAL PNEUMONITIS OR FIBROSIS, OR BOTH, ARE ALSO COMMON MANIFESTATIONS OF THE CHRONIC PULMONARY REACTION. FEVER IS RARELY PROMINENT. THE SEVERITY OF CHRONIC PULMONARY REACTIONS AND THEIR DEGREE OF RESOLUTION APPEAR TO BE RELATED TO THE DURATION OF THERAPY AFTER THE FIRST CLINICAL SIGNS APPEAR.

PULMONARY FUNCTION MAY BE IMPAIRED PERMANENTLY, EVEN AFTER CESSATION OF THERAPY. THE RISK IS GREATER WHEN CHRONIC PULMONARY REACTIONS ARE NOT RECOGNIZED EARLY. In subacute pulmonary reactions, fever and eosinophilia occur less often than in the acute form.

Upon cessation of therapy, recovery may require several months. If the symptoms are not recognized as being drug-related and nitrofurantoin therapy is not stopped, the symptoms may become more severe. Acute pulmonary reactions are commonly manifested by fever, chills, cough, chest pain, dyspnea, pulmonary infiltration with consolidation or pleural effusion on x-ray, and eosinophilia.

Acute reactions usually occur within the first week of treatment and are reversible with cessation of therapy. Resolution often is dramatic (see WARNINGS ). Changes in EKG (e.g., non-specific ST/T wave changes, bundle branch block) have been reported in association with pulmonary reactions.

Cyanosis has been reported rarely. Hepatic Hepatic reactions, including hepatitis, cholestatic jaundice, chronic active hepatitis, and hepatic necrosis, occur rarely (see WARNINGS ). Neurologic Peripheral neuropathy, which may become severe or irreversible, has occurred.

Fatalities have been reported. Conditions such as renal impairment (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine), anemia, diabetes mellitus, electrolyte imbalance, vitamin B deficiency, and debilitating diseases may increase the possibility of peripheral neuropathy (see WARNINGS ). Asthenia, vertigo, nystagmus, dizziness, headache, and drowsiness also have been reported with the use of nitrofurantoin.

Benign intracranial hypertension (pseudotumor cerebri), confusion, depression, optic neuritis, and psychotic reactions have been reported rarely. Bulging fontanels, as a sign of benign intracranial hypertension in infants, have been reported rarely. Dermatologic Exfoliative dermatitis and erythema multiforme (including Stevens-Johnson syndrome) have been reported rarely.

Transient alopecia also has been reported. Allergic A lupus-like syndrome associated with pulmonary reactions to nitrofurantoin has been reported. Also, angioedema; maculopapular, erythematous, or eczematous eruptions; pruritus; urticaria; anaphylaxis; arthralgia; myalgia; drug fever; chills; and vasculitis (sometimes associated with pulmonary reactions) have been reported.

Hypersensitivity reactions represent the most frequent spontaneously-reported adverse events in worldwide postmarketing experience with nitrofurantoin formulations. Gastrointestinal Nausea, emesis, and anorexia occur most often. Abdominal pain and diarrhea are less common gastrointestinal reactions.

These dose-related reactions can be minimized by reduction of dosage. Sialadenitis and pancreatitis have been reported. There have been sporadic reports of pseudomembranous colitis with the use of nitrofurantoin.

The onset of pseudomembranous colitis symptoms may occur during or after antimicrobial treatment (see WARNINGS ). Hematologic Cyanosis secondary to methemoglobinemia has been reported rarely. Miscellaneous As with other antimicrobial agents, superinfections caused by resistant organisms, e.g., Pseudomonas species or Candida species, can occur.

Laboratory Adverse Events…

🔄 Drug Interactions 73 words

Drug Interactions Antacids containing magnesium trisilicate, when administered concomitantly with nitrofurantoin, reduce both the rate and extent of absorption. The mechanism for this interaction probably is adsorption of nitrofurantoin onto the surface of magnesium trisilicate. Uricosuric drugs, such as probenecid and sulfinpyrazone, can inhibit renal tubular secretion of nitrofurantoin.

The resulting increase in nitrofurantoin serum levels may increase toxicity, and the decreased urinary levels could lessen its efficacy as a urinary tract antibacterial.

🔄 Drug / Laboratory Test Interactions 37 words

Drug/Laboratory Test Interactions As a result of the presence of nitrofurantoin, a false-positive reaction for glucose in the urine may occur. This has been observed with Benedict's and Fehling's solutions but not with the glucose enzymatic test.

🤰 Pregnancy 197 words

Pregnancy Teratogenic Effects Pregnancy Category B Several reproduction studies have been performed in rabbits and rats at doses up to six times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to nitrofurantoin. In a single published study conducted in mice at 68 times the human dose (based on mg/kg administered to the dam), growth retardation and a low incidence of minor and common malformations were observed. However, at 25 times the human dose, fetal malformations were not observed; the relevance of these findings to humans is uncertain.

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. Non-Teratogenic Effects Nitrofurantoin has been shown in one published transplacental carcinogenicity study to induce lung papillary adenomas in the F1 generation mice at doses 19 times the human dose on a mg/kg basis.

The relationship of this finding to potential human carcinogenesis is presently unknown. Because of the uncertainty regarding the human implications of these animal data, this drug should be used during pregnancy only if clearly needed.

🧒 Pediatric Use 17 words

Pediatric Use Nitrofurantoin macrocrystals are contraindicated in infants below the age of one month (see CONTRAINDICATIONS ).

🧓 Geriatric Use ~1 min read

Geriatric Use Clinical studies of nitrofurantoin macrocrystals did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. Spontaneous reports suggest a higher proportion of pulmonary reactions, including fatalities, in elderly patients; these differences appear to be related to the higher proportion of elderly patients receiving long-term nitrofurantoin therapy.

As in younger patients, chronic pulmonary reactions generally are observed in patients receiving therapy for six months or longer (see WARNINGS ). Spontaneous reports also suggest an increased proportion of severe hepatic reactions, including fatalities, in elderly patients (see WARNINGS ). In general, the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy should be considered when prescribing nitrofurantoin macrocrystals.

This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Anuria, oliguria, or significant impairment of renal function (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine) are contraindications (see CONTRAINDICATIONS ). Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

🆘 Overdosage 47 words

OVERDOSAGE Occasional incidents of acute overdosage of nitrofurantoin macrocrystals have not resulted in any specific symptoms other than vomiting. Induction of emesis is recommended. There is no specific antidote, but a high fluid intake should be maintained to promote urinary excretion of the drug. It is dialyzable.

🧬 Clinical Pharmacology 105 words

CLINICAL PHARMACOLOGY Nitrofurantoin macrocrystals are a larger crystal form of nitrofurantoin. The absorption of nitrofurantoin macrocrystals is slower and its excretion somewhat less when compared to nitrofurantoin. Blood concentrations at therapeutic dosage are usually low.

It is highly soluble in urine, to which it may impart a brown color. Following a dose regimen of 100 mg q.i.d. for 7 days, average urinary drug recoveries (0 to 24 hours) on day 1 and day 7 were 37.9% and 35%. Unlike many drugs, the presence of food or agents delaying gastric emptying can increase the bioavailability of nitrofurantoin macrocrystals, presumably by allowing better dissolution in gastric juices.

🧬 Mechanism of Action 104 words

Mechanism of Action The mechanism of the antimicrobial action of nitrofurantoin is unusual among antibacterials. Nitrofurantoin is reduced by bacterial flavoproteins to reactive intermediates which inactivate or alter bacterial ribosomal proteins and other macromolecules. As a result of such inactivations, the vital biochemical processes of protein synthesis, aerobic energy metabolism, DNA synthesis, RNA synthesis, and cell wall synthesis are inhibited.

Nitrofurantoin is bactericidal in urine at therapeutic doses. The broad-based nature of this mode of action may explain the lack of acquired bacterial resistance to nitrofurantoin, as the necessary multiple and simultaneous mutations of the target macromolecules would likely be lethal to the bacteria.

📦 How Supplied / Storage and Handling 142 words

HOW SUPPLIED Nitrofurantoin Capsules USP (Macrocrystals) are available as pink opaque/white opaque capsules, imprinted with z, “Zenith 50 mg” on the cap and “2130”, underlined with a double bar, on the body, in black ink, containing 50 mg nitrofurantoin macrocrystals, packaged in bottles of 100 (NDC 0115-1643-01) and 1000 capsules (NDC 0115-1643-03). Nitrofurantoin Capsules USP (Macrocrystals) are available as pink opaque capsules, imprinted with z, “Zenith 100 mg” on the cap and “2131”, underlined with a triple bar, on the body, in black ink, containing 100 mg nitrofurantoin macrocrystals, packaged in bottles of 100 (NDC 0115-1645-01) and 1000 capsules (NDC 0115-1645-03).

Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure (as required). KEEP THIS AND ALL MEDICATIONS OUT OF THE REACH OF CHILDREN.

📋 Description 136 words

DESCRIPTION Nitrofurantoin Capsules, USP (Macrocrystals) are a synthetic chemical of controlled crystal size. It is a stable, yellow, crystalline compound. Nitrofurantoin Capsules, USP (Macrocrystals) are an antibacterial agent for specific urinary tract infections.

Nitrofurantoin, USP (macrocrystals) is chemically designated as 2,4-Imidazolidinedione, 1-[[(5-nitro-2-furanyl)methylene]amino]- and has the following structural formula: C 8 H 6 N 4 O 5 (anhydrous) M.W. 238.16 Each capsule, for oral administration, contains 50 mg or 100 mg of nitrofurantoin, USP (macrocrystals). In addition, each capsule contains the following inactive ingredients: corn starch, edible black ink (black iron oxide, D&C Yellow No.

10 Aluminum Lake, FD&C Blue No. 1 Aluminum Lake, FD&C Blue No. 2 Aluminum Lake, FD&C Red No.

40 Aluminum Lake, propylene glycol, shellac glaze), gelatin, lactose monohydrate, talc, titanium dioxide and colorant D&C Red No. 33. structural formula - nitrofurantoin, USP

💬 Information for Patients ~1 min read

Information for Patients Patients should be advised to take nitrofurantoin macrocrystals with food to further enhance tolerance and improve drug absorption. Patients should be instructed to complete the full course of therapy; however, they should be advised to contact their physician if any unusual symptoms occur during therapy. Many patients who cannot tolerate microcrystalline nitrofurantoin are able to take nitrofurantoin macrocrystals without nausea.

Patients should be advised not to use antacid preparations containing magnesium trisilicate while taking nitrofurantoin macrocrystals. Patients should be counseled that antibacterial drugs including nitrofurantoin macrocrystals should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold).

When nitrofurantoin macrocrystals are prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by nitrofurantoin macrocrystals or other antibacterial drugs in the future.

Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.

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.