Methenamine Hippurate 1000 mg Tablet, 100-count — NDC 42571-332-01 (Billing 42571-0332-01)
This is a package of 100 tablets of Methenamine Hippurate 1000 mg Tablet from Micro Labs Limited, marketed since Aug 2019 and currently FDA-listed; retail pharmacies pay about $0.3126 per tablet (NADAC). It is the main listing for this product, which comes in 2 package sizes.
Identity & classification
Regulatory identifiers FDA, NLM and CMS codes for this package
Drug-database identifiers Medi-Span GPI and First Databank GCN / HICL / AHFS classification
- GSN (GCN sequence number): 009457
- GCN: 41980
- GPI-14 (Medi-Span): 16800020200305
- HICL (First Databank): 004101
- AHFS class code: 08:36.00.00
- RxCUI (RxNorm): 992150
Where does this data come from?
- FDA openFDA NDC Directory · synced Oct 1, 2026
- FDA label on DailyMed · label index refreshed Oct 1, 2026
- RxNorm (NLM RxNav) · catalog refreshed Oct 1, 2026
- Medi-Span GPI (licensed)
- First Databank (licensed) · refreshed Oct 1, 2026
RxNorm drug class
This medicine belongs to the Other antibacterials class.
Where does this data come from?
- RxClass (NLM) · catalog refreshed Oct 1, 2026
Clinical
Methenamine, an antibiotic, eliminates bacteria that cause urinary tract infections. It usually is used on a long-term basis to treat chronic infections and to prevent recurrence of infections. Antibiotics will not work for colds, flu, or other viral infections. This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
Read the full MedlinePlus article ↗- That's a great question. Methenamine isn't used to clear an active infection — it's used to prevent another one from taking hold. Once your other antibiotic has done that job, meth...
- Why do I need to take methenamine if my infection is already gone?
- Yes, it actually does. Methenamine only converts into its active antibacterial form in acidic urine. Foods and medications that make your urine more alkaline — less acidic — can re...
- Does it matter what I eat or drink while I'm on this medication?
Patient education
Supplement & herbal interactions
Some supplements/herbs that may interact with Methenamine Hippurate — tap one for details:
Methenamine Hippurate may be associated with lower levels of 7 nutrients — worth a chat with your pharmacist, not a cause for alarm.
Where does this data come from?
- MedlinePlus (NLM) · refreshed Oct 1, 2026
- FDA label on DailyMed · label index refreshed Oct 1, 2026
Ask a licensed pharmacist directly — free, answered by our team.
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 system | Per ea | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | $0.313 | $31.26 / 100 tablets |
| Medicaid paysCMS SDUD · 12 mo | $0.5666 | $56.66 / 100 tablets |
| Medicare drug plans payPart D · Q2 2026 | $0.5951 | $59.51 / 100 tablets |
Where does this data come from?
- CMS NADAC weekly file · file of Sep 30, 2026
- CMS ASP pricing files · refreshed Sep 20, 2026
- CMS Medicaid State Drug Utilization Data · through Q1 2026
- CMS Part D plan pricing files · refreshed Sep 24, 2026
- VA National Acquisition Center price file
Packaging — all sizes for this product
| Package NDC | Description | Per unit | Per pack | Marketing start | Marketing end | Status |
|---|---|---|---|---|---|---|
| 42571-0332-01 You're viewing this Main listing | 100 TABLET in 1 BOTTLE | $0.3126 / ea | $31.26 | 2019-08-15 | — | Active |
| 42571-0332-23 42571-332-23 | 80 TABLET in 1 CARTON | — | — | 2019-08-15 | — | Active |
You're viewing the largest 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 this package?
How does this package differ from NDC 42571-0332-23?
What NDC number is used to bill for this package of Methenamine Hippurate 1000 mg Tablet?
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.
Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Methenamine Hippurate 1000 mgthis 42571-0332-01 | Micro | 100 tablets | $0.313 | AB | Availability likely | — |
| Methenamine Hippurate 1 g 47781-0577-01 | Alvogen | 100 tablets | $0.313 | AB | Availability likely | — |
| Methenamine Hippurate 1000 mg 50268-0549-15 | AvPAK | 50 tablets | $0.313 | AB | Availability likely | — |
| Methenamine Hippurate 1 g 50742-0142-01 | Ingenus | 100 tablets | $0.313 | AB | Availability likely | — |
| Methenamine Hippurate 1 g 59746-0797-01 | Jubilant | 100 tablets | $0.313 | AB | Availability likely | — |
| Methenamine Hippurate 1000 mg 60687-0694-21 | American | 30 tablets | $0.313 | AB | Availability likely | — |
| Methenamine Hippurate 1 g 65862-0782-01 | Aurobindo | 100 tablets | $0.313 | AB | Availability likely | — |
| Methenamine hippurate 1 g 72578-0175-01 | Viona | 100 tablets | $0.313 | AB | Availability likely | — |
| Methenamine Hippurate 1 g 72603-0816-01 | NorthStar | 100 tablets | $0.313 | AB | Availability likely | — |
| Methenamine Hippurate 1 g 51407-0880-01 | Golden | 100 tablets | — | AB | FDA listed | — |
| Methenamine Hippurate 1 g 70685-0050-01 | Esjay | 100 tablets | — | AB | Discontinued | — |
| Methenamine hippurate 1 g 70771-1919-01 | Zydus | 100 tablets | — | AB | FDA listed | — |
Where does this data come from?
- FDA openFDA NDC Directory · synced Oct 1, 2026
- FDA Orange Book · refreshed Sep 3, 2026
- CMS NADAC weekly file · file of Sep 30, 2026
Availability & generic status
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?
- FDA Orange Book · refreshed Sep 3, 2026
What it looks like
Where does this data come from?
- FDA label on DailyMed · label index refreshed Oct 1, 2026
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.
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UNII 70097M6I30
Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
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UNII RDH86HJV5Z
Povidone K90 is a synthetic polymer made from a chemical called vinyl pyrrolidone. It acts as a binder to hold pill ingredients together and as a dispersant to help the medicine break down and dissolve properly in your body.
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UNII ETJ7Z6XBU4
Silicon dioxide is a naturally occurring mineral used as a glidant and anti-caking agent. It helps powder ingredients flow smoothly and prevents clumping during manufacturing and storage.
3 inactive ingredients listed in the exact product block matched to this NDC.
Where does this data come from?
ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.- FDA label on DailyMed · label index refreshed Oct 1, 2026
- FDA openFDA NDC Directory · synced Oct 1, 2026
Inactive ingredient FAQ
Are inactive ingredients the same for every manufacturer?
Why might an inactive ingredient be missing?
Can inactive ingredients matter?
Manufacturer & labeler
Where does this data come from?
- FDA openFDA NDC Directory · synced Oct 1, 2026
- Drugs@FDA
Full prescribing information FDA SPL
🎯 Indications and Usage ▾
INDICATIONS Methenamine hippurate tablets USP are indicated for prophylactic or suppressive treatment of frequently recurring urinary tract infections when long-term therapy is considered necessary. This drug should only be used after eradication of the infection by other appropriate antimicrobial agents. To reduce the development of drug-resistant bacteria and maintain the effectiveness of methenamine hippurate and other antibacterial drugs, methenamine hippurate 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.
⏱️ Dosage and Administration ▾
DOSAGE AND ADMINISTRATION 1 tablet (1 g) twice daily (morning and night) for adults and pediatric patients over 12 years of age. 1/2 to 1 tablet (0.5 to 1 g) twice daily (morning and night) for pediatric patients 6 to 12 years of age. Since the antibacterial activity of methenamine hippurate is greater in acid urine, restriction of alkalinizing foods and medications is desirable.
If necessary, as indicated by urinary pH and clinical response, supplemental acidification of the urine should be instituted. The efficacy of therapy should be monitored by repeated urine cultures.
⛔ Contraindications ▾
CONTRAINDICATIONS Methenamine hippurate tablets USP are contraindicated in patients with renal insufficiency, severe hepatic insufficiency, or severe dehydration. Methenamine preparations should not be given to patients taking sulfonamides because some sulfonamides may form an insoluble precipitate with formaldehyde in the urine.
⚠️ Warnings ▾
WARNINGS Large doses of methenamine (8 grams daily for 3 to 4 weeks) have caused bladder irritation, painful and frequent micturition, albuminuria, and gross hematuria.
🤒 Adverse Reactions ▾
ADVERSE REACTIONS Minor adverse reactions have been reported in less than 3.5% of patients treated. These reactions have included nausea, upset stomach, dysuria, and rash. To report SUSPECTED ADVERSE REACTIONS, contact Micro Labs USA Inc. at 1-855-839-8195 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
🧓 Geriatric Use ▾
Geriatric Use Clinical studies of methenamine hippurate 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. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy.
Methenamine hippurate is contraindicated in patients with renal insufficiency and severe hepatic insufficiency (s ee CONTRAINDICATIONS ). Information for Patients Patients should be counseled that antibacterial drugs including methenamine hippurate should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold).
When methenamine hippurate is 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 methenamine hippurate or other antibacterial drugs in the future.
📦 How Supplied / Storage and Handling ▾
HOW SUPPLIED White to off white colored, capsule shaped, biconvex tablets, debossed with "H" and "1" on either side of breakline on one side and other side plain with approximate length 20.00 mm, width 8.00 mm and thickness 7.40 mm. Bottles of 100 NDC 42571-332-01 Carton of 80 (8 x10) Unit-dose Tablets NDC 42571-332-23 Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C and 30°C (59°F and 86°F) [see USP Controlled Room Temperature]. Dispense in well-closed, light-resistant container with child-resistant closure.
Manufactured by: Micro Labs Limited Goa-403 722, INDIA. Manufactured for: Micro Labs USA, Inc. Somerset, NJ 08873 Rev.10/2021
📋 Description ▾
DESCRIPTION Each white to off-white capsule-shaped tablet contains 1 g Methenamine Hippurate USP which is the Hippuric Acid Salt of Methenamine (hexamethylene tetramine). The tablet also contains inactive ingredients Colloidal silicon dioxide, magnesium stearate and povidone K90.
⚠️ Precautions ▾
PRECAUTIONS Prescribing methenamine hippurate in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria. Care should be taken to maintain an acid pH of the urine, especially when treating infections due to urea-splitting organisms such as Proteus and strains of Pseudomonas . In a few instances in one study, the serum transaminase levels were slightly elevated during treatment but returned to normal while the patients were still taking methenamine hippurate.
Because of this report, it is recommended that liver function studies be performed periodically on patients taking the drug, especially those with liver dysfunction. Use in Pregnancy: In early pregnancy the safe use of methenamine hippurate is not established. In the last trimester, safety is suggested, but not definitely proved.
No adverse effects on the fetus were seen in studies in pregnant rats and rabbits. Methenamine hippurate taken during pregnancy can interfere with laboratory tests of urine estriol (resulting in unmeasurably low values) when acid hydrolysis is used in the laboratory procedure. This interference is due to the presence in the urine of methenamine and/or formaldehyde.
Enzymatic hydrolysis, in place of acid hydrolysis, will circumvent this problem. Geriatric Use Clinical studies of methenamine hippurate 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.
In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy. Methenamine hippurate is contraindicated in patients with renal insufficiency and severe hepatic insufficiency (s ee CONTRAINDICATIONS ). Information for Patients Patients should be counseled that antibacterial drugs including methenamine hippurate should only be used to treat bacterial infections.
They do not treat viral infections (e.g., the common cold). When methenamine hippurate is 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 methenamine hippurate or other antibacterial drugs in the future.
📄 Package Label / Principal Display Panel ▾
PACKAGE LABEL.PRINCIPAL DISPLAY PANEL NDC 42571-332-01 Methenamine Hippurate Tablets, USP 1 g Rx Only 100 Tablets Micro labs Limited methenaminehipp-lbl.jpg