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UTAC tablets

Generic name: methenamine mandelate and sodium phosphate, monobasic, monohydrate
Dosage form: tablet, film coated
Drug class: Urinary anti-infectives

Medically reviewed by Last updated on Apr 21, 2022.

Disclaimer: This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA. For further information about unapproved drugs, click here.

Rx Only

UTAC tablets Description

Each Tablet Contains:
Methenamine Mandelate 500 mg
Sodium Phosphate Monobasic, Monohydrate 500 mg

Inactive Ingredients: D&C Yellow No.10 Lake, Hypromellose, Magnesium Silicate, Magnesium Stearate, Microcrystalline Cellulose, Mineral Oil, Polyvinylpyrrolidone, Silica, Sodium Starch Glycolate, Starch, Stearic Acid, Titanium Dioxide and Triacetin.

UTAC tablets - Clinical Pharmacology

Methenamine mandelate is rapidly absorbed and excreted in the urine. Formaldehyde is released by acid hydrolysis from methenamine with bactericidal levels rapidly reached at pH 5.0- 5.5. Proportionally less formaldehyde is released as urinary pH approaches 6.0 and insufficient quantities are released above this level for therapeutic response. In acid urine, mandelic acid exerts its antibacterial action and also contributes to the acidification of the urine. Mandelic acid is excreted by both glomerular filtration and tubular excretion. In acid urine, there is equally effective antibacterial activity against both gram-positive and gram-negative organisms, since the antibacterial action of mandelic acid and formaldehyde is nonspecific. With Proteus vulgaris and urea splitting strains of Pseudomonas and Aerobacter, results may be discouraging and particular attention is required in monitoring urinary pH and overall management.

Indications and Usage for UTAC tablets

For the suppression or elimination of bacteriuria associated with chronic and recurrent infections of the urinary tract, including pyelitis, pyelonephritis, cystitis, and infected residual urine accompanying neurogenic bladder. When used as recommended, UTAC™ is particularly suitable for long-term therapy because of its relative safety and because resistance to the nonspecific bactericidal action of formaldehyde does not develop. Pathogens resistant to other antibacterial agents may respond because of the nonspecific effect of formaldehyde formed in an acid urine.

Prophylactic Use Rationale

Urine is a good culture medium for many urinary pathogens. Inoculation by a few organisms (relapse or reinfection) may lead to bacteriuria in susceptible individuals. Thus, the rationale of management in recurring urinary tract infection (bacteriuria) is to change the urine from a growth-supporting to a growth-inhibiting medium. There is a growing body of evidence that long-term administration of methenamine can prevent recurrence of bacteriuria in patients with chronic pyelonephritis.

Therapeutic Use Rationale

Helps to sterilize the urine and in some situations in which underlying pathologic conditions prevent sterilization by any means, can help to suppress bacteriuria. As part of the overall management of the urinary tract infection, a thorough diagnostic evaluation should accompany the use of this product.


This product is contraindicated in patients with renal insufficiency, severe hepatic disease, severe dehydration, hyperphosphatemia, and in patients who have exhibited hypersensitivity to any components of this product.



If pregnant, or planning to become pregnant or are currently breast-feeding please contact your physician, or health-care provider before using or continuing use.

This product should not be used as the sole therapeutic agent in acute parenchymal infections causing systemic symptoms such as chills and fever.

Utac™ contains approximately 83 mg of sodium per tablet and should be used with caution in patients on a sodium-restricted diet.

Sodium phosphates should be used with caution in the following conditions: cardiac failure; peripheral or pulmonary edema; hypernatremia; hypertension; toxemia of pregnancy; hypoparathyroidism; and acute pancreatitis. High serum phosphate levels increase the incidence of extraskeletal calcification.

Large doses of methenamine (8 grams daily for 3 to 4 weeks) have caused bladder irritation, painful and frequent micturition, albuminuria and gross hematuria. Dysuria may occur, although usually at higher than recommended doses, and can be controlled by reducing the dosage. This product contains a urinary acidifier and can cause metabolic acidosis.

Care should be taken to maintain an acidic urinary pH (below 5.5), especially when treating infections due to urea-splitting organisms such as Proteus and strains of Pseudomonas. Drugs and/or foods which produce an alkaline urine should be restricted. Frequent urine pH tests are essential. If acidification of the urine is contraindicated or unattainable, use of this product should be discontinued.

Information for Patients

To assure an acidic pH, patients should be instructed to restrict or avoid most fruits, milk and milk products, and antacids containing sodium carbonate or bicarbonate.

Laboratory Tests

As with all urinary tract infections, the efficacy of therapy should be monitored by repeated urine cultures. During long-term therapy, careful monitoring of renal function, serum phosphorus and sodium may be required at periodic intervals.

Drug Interactions

Formaldehyde and sulfamethizole form an insoluble precipitate in acid urine and increase the risk of crystalluria; therefore, these products should not be used concurrently. Thiazide diuretics, carbonic anhydrase inhibitors, antacids, or urinary alkalinizing agents should not be used concurrently since they may cause the urine to become alkaline and reduce the effectiveness of methenamine by inhibiting its conversion to formaldehyde. Concurrent use of antihypertensives, especially diazoxide, guanethidine, hydralazine, methyldopa, or rauwolfia alkaloids; or corticosteroids, especially mineralocorticoids or corticotropin, with sodium phosphates may result in hypernatremia. Concurrent use of salicylates may lead to increased serum salicylate levels since excretion of salicylates is reduced in acidified urine. Serum salicylate levels should be closely monitored to avoid toxicity.

Laboratory Test Interactions

Formaldehyde interferes with fluorometric procedures for determination of urinary catecholamines and vanilmandelic acid (VMA) causing erroneously high results. Formaldehyde also causes falsely decreased urine estriol levels by reacting with estriol when acid hydrolysis techniques are used; estriol determinations which use enzymatic hydrolysis are unaffected by formaldehyde. Formaldehyde causes falsely elevated 17-hydroxycorticosteroid levels when the Porter-Silber method is used and falsely decreased 5-hydroxyindoleacetic acid (5HIAA) levels by inhibiting color development when nitrosonaphthol methods are used.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Long-term animal studies to evaluate the carcinogenic, mutagenic, or impairment of fertility potential of this product have not been performed.


Teratogenic Effects

Pregnancy Category C

Animal reproduction studies have not been conducted with Utac™. It is also not known whether this product can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. Since methenamine is known to cross the placental barrier, this product should be given to a pregnant woman only if the potential benefit justifies potential risk to the fetus.

Nursing Mothers

Methenamine is excreted in breast milk. Because of the potential for adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug.

Pediatric Use

Safety and effectiveness in the pediatric population have not been established.

Adverse Reactions

Gastrointestinal disturbances (nausea, stomach upset), generalized skin rash, dysuria, painful or difficult urination may occur occasionally with the use of methenamine preparations. Microscopic and rarely, gross hematuria have also been reported.

Gastrointestinal upset (diarrhea, nausea, stomach pain, and vomiting) may occur with the use of sodium phosphates. Also, bone or joint pain (possible phosphate induced osteomalacia) could occur. The following adverse effects may be observed (primarily from sodium): headaches; dizziness; mental confusion; seizures; weakness or heaviness of legs; unusual tiredness or weakness; muscle cramps; numbness; tingling, pain or weakness of hands or feet; numbness or tingling around lips; fast or irregular heartbeat; shortness of breath or troubled breathing; swelling of feet or lower legs; unusual weight gain; low urine output; unusual thirst.

UTAC tablets Dosage and Administration


Initially, 2 tablets 4 times daily with a full glass of water. For maintenance 2-4 tablets daily, in divided doses with a full glass of water.

Do not exceed recommended dosage.

How is UTAC tablets Supplied

Yellow, film-coated, oval-shaped tablet debossed "B 199". NDC 51991-199-01, bottles of 100.

Store at 25°C (77°F); excursions permitted to 15°-30°C (59°-86°F). See USP Controlled Room Temperature.

Protect from light and moisture.

Dispense in a tight, light-resistant container with a child-resistant closure as defined in the USP/NF.

All prescription substitutions using this product shall be pursuant to state statutes as applicable. This is not an Orange Book product.

Keep this and all medications out of the reach of children. In case of accidental overdose seek professional assistance or contact a poison control center immediately.

Distributed by:
Breckenridge Pharmaceutical, Inc.
Boca Raton, FL 33487

Manufactured by:
Contract Pharmacal Corp.
Hauppauge, NY 11788 USA

Rev. 06/09

PRINCIPAL DISPLAY PANEL- 100 Tablet Bottle Label

Pharmaceutical, Inc.

NDC 51991-199-01

Utac™ Tablets
Urinary Antiseptic /Acidifier

Do not use if any tamper evident seal
is broken or missing.

Rx Only

100 Tablets

methenamine mandelate and sodium phosphate, monobasic, monohydrate tablet, film coated
Product Information
Product Type HUMAN PRESCRIPTION DRUG LABEL Item Code (Source) NDC:51991-199
Route of Administration ORAL DEA Schedule
Active Ingredient/Active Moiety
Ingredient Name Basis of Strength Strength
Methenamine Mandelate (Methenamine Mandelate) Methenamine Mandelate 500 mg
Sodium Phosphate, Monobasic, Monohydrate (Sodium Cation) Sodium Phosphate, Monobasic, Monohydrate 500 mg
Inactive Ingredients
Ingredient Name Strength
D&C Yellow No. 10
Magnesium Silicate
Magnesium Stearate
Cellulose, Microcrystalline
Mineral Oil
Silicon Dioxide
Stearic Acid
Titanium Dioxide
Aluminum Oxide
Sodium Starch Glycolate Type A Potato
Starch, Tapioca
Product Characteristics
Color YELLOW Score 2 pieces
Shape OVAL Size 19mm
Flavor Imprint Code B;199
# Item Code Package Description
Marketing Information
Marketing Category Application Number or Monograph Citation Marketing Start Date Marketing End Date
UNAPPROVED DRUG OTHER 08/01/2008 05/31/2012
Labeler - Breckenridge Pharmaceutical, Inc. (150554335)
Name Address ID/FEI Operations
Contract Pharmacal Corporation 057795122 MANUFACTURE
Breckenridge Pharmaceutical, Inc.

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