HOW SHOULD THIS MEDICINE BE USED?

Hiprex® (methenamine hippurate tablets USP) should be taken by the mouth as directed by your doctor.  Take each dose with a full glass of water. Plenty of fluid should be consumed while taking Hiprex.

Your doctor may recommend drinking additional water and/or certain fruit juices (e.g., cranberry, plum, prune) and increased protein in the diet while taking Hiprex to ensure adequate hydration and acidity of the urine. It may also be recommended to avoid citrus fruits and juices (e.g., orange, grapefruit, lemon), milk and dairy products, and antacids during treatment with Hiprex, as these products may decrease the effectiveness of the medicine.

When you first take Hiprex, it is common to feel better shortly after beginning the medication, but you must make sure to take the medicine exactly as prescribed by your doctor and for the entire course of therapy in order for it to work properly.   If you stop taking the medicine because you feel better, this may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance to antibacterial drugs and will not be treatable by Hiprex or any other antibacterial drugs in the future.

WHO SHOULD NOT TAKE HIPREX® (methenamine hippurate tablets USP)?

You should not take Hiprex® (methenamine hippurate tablets USP)  if you are allergic to it; or to formaldehyde; or if you have any other allergies to the inactive ingredients. See the full package insert for a list of all ingredients in Hiprex.

Tell your doctor your medical history so he or she can determine if Hiprex is a proper medication for your condition, especially if you have or have had kidney problems, liver problems, or dehydration.

Before having surgery, tell your doctor about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Your doctor will determine if the benefits of taking this medicine outweigh the risks.

This drug passes into breast milk and the effect on a nursing infant is unknown. Consult your doctor before breast-feeding.

Take all of the Hiprex tablets that have been prescribed for you even if you begin to feel better. Symptoms may start to improve before the infection is completely treated.

TAKING OTHER MEDICINES:

Drug interactions may change how your medicines work or increase your risk for serious side effects. Do not start, stop or change the dosage of any medications without your doctor’s approval.

Some products that may interact with this drug include:

  • sulfonamide drugs (including sulfa antibiotics such as sulfamethizole)
  • products that decrease the amount of acid in the urine (urinary alkalinizers such as antacids, sodium bicarbonate, potassium or sodium citrate, carbonic anhydrase inhibitors such as acetazolamide).

This medication may interfere with certain laboratory tests, possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

THIS LIST IS NOT COMPLETE AND OTHER DRUGS MAY INTERACT WITH HIPREX.  TELL YOUR DOCTORS ABOUT ALL MEDICINES YOU USE.  THIS INCLUDES PRESCRIPTION, OVER-THE-COUNTER, VITAMIN AND HERBAL PRODUCTS.  DO NOT START A NEW MEDICATION WITHOUT TELLING YOUR DOCTOR.

IMPORTANT SAFETY INFORMATION

Download Full Prescribing Information

Hiprex® (methenamine hippurate tablets USP)

WHAT IS HIPREX USED FOR?

Hiprex® (methenamine hippurate tablets USP) are used to prevent or control recurring urinary tract infections caused by certain bacteria.  Hiprex is not used to treat an active infection; Hiprex should only be used after the infection has been treated with other antibiotics.

WHEN SHOULD I NOT TAKE THE DRUG?

You should not take Hiprex if you are allergic to methenamine hippurate, formaldehyde, or any of the other ingredients in the drug, or if you are taking a sulfonamide drug.

You should not take Hiprex unless your doctor has confirmed that your infection is caused by bacteria that is susceptible to Hiprex.  Hiprex is effective only against bacterial infections in the urinary tract.  It will not work for other types of bacterial infections or for viral infections (such as the common cold or flu).  Unnecessary use of Hiprex can lead to its decreased effectiveness and the development of antibiotic-resistant bacteria.

You should not take Hiprex if you have kidney failure, severe liver insufficiency, or you are severely dehydrated.

WHAT WARNINGS SHOULD I KNOW ABOUT HIPREX?

Large doses of Hiprex (8 pills/day for 3-4 weeks) can cause bladder irritation, painful and frequent urination, cause protein to leak into the urine, and cause blood in the urine.

You should also be aware that taking Hiprex before a bacterial infection has been confirmed increases the risk of developing drug resistant bacteria.

When taking Hiprex:

Hiprex should only be used to treat bacterial infections.  Hiprex will not treat a viral infection (such as the common cold)

WHAT SHOULD I TELL MY HEALTHCARE PROVIDER?

WHAT OTHER MEDICATIONS MIGHT INTREACT WITH HIPREX?

WHAT ARE THE SIDE EFFECTS OF HIPREX?

A very serious allergic reaction to this drug is rare. Seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, or trouble breathing.

Most side effects have been mild and reported in < 3.5% of people taking Hiprex.

These minor side effects have included:

Large doses of Hiprex (8 pills daily for 3-4 weeks) have caused bladder irritation, painful and frequent urination, excess protein in the urine and blood in the urine.  If you experience any of these side effects, contact your doctor immediately.

WHAT IF I OVERDOSE?

There is no specific treatment for suspected overdose.

Seek emergency help.  Supportive measures should be taken.

Call the Poison Control Hotline (1-800-222-1222).