Hiprex is a prescription medication that is used to prevent recurrent bladder infections from returning. Hiprex contains methenamine hippurate and is usually taken after other antibiotics have treated the initial infection. Hiprex is an antibiotic that is only effective against bacterial infections in the urinary tract and will not work to treat other bacterial infections.

Make sure to always read the patient information and instructions before using this medication. Always follow your doctor’s directions.

• Take Hiprex for the full amount of time prescribed even if your symptoms have improved.
• Drink plenty of liquids while taking Hiprex.
• Follow your doctor’s directions about what to eat and drink carefully.
• Do not take more of this medication or more frequently than prescribed. The medication will not be more effective but you may increase the risk of side effects.

Tell your doctor and pharmacist:

• About your drug and other allergies, especially to aspirin or yellow food dye.
• If you take any other prescription or over-the-counter medications.
• Your medical history particularly of kidney disease, liver disease, asthma, or dehydration.
• If you are breast-feeding.

You should also know:

• Hiprex may affect the results of medical tests. Tell all of your doctors that you take this medication.
• If taken during early pregnancy, this medication can harm an unborn baby.

Common side effects of Hiprex include but are not limited to:

• Difficult urination.
• Rashes.
• Nausea.
• Upset stomach.

Get medical help if you have any of the following side effects of methenamine hippurate.

• Increased urination.
• Painful urination.
• Blood in your urine.
• Any new or worsening symptom.
• Symptoms of an allergic reaction such as difficulty breathing, hives, or swelling in your face, lips, or throat.

What should I do if I miss a dose of Hiprex?

If you miss a dose of Hiprex, you should take it as soon as you remember. However, if it is almost time for your next dose, then skip your missed dose.

What is the strength of Hiprex?

Both Hiprex and the generic alternative methenamine hippurate are available in a strength of 1%.