Hiprex contains the active ingredient methenamine hippurate, which is a hippurate salt form. It belongs to the drug class of urinary tract antiseptics. The formulation is a scored tablet with a dosage strength of 1 gram, designed to be taken orally. Key inactive ingredients include magnesium stearate, povidone, and saccharin sodium.

How should I use this medication?

Take this medication by mouth with a full glass of water. Take it as directed on the prescription label. Do not crush or chew. Take your medication at regular intervals. Do not take your medication more often than directed. Take all of this medication unless your care team tells you to stop it early. Keep taking it even if you think you are better. Talk to your care team about the use of this medication in children. While it may be prescribed for children as young as 6 years for selected conditions, precautions do apply.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once. NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

Where should I keep my medication?

Keep out of the reach of children and pets. Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Keep container tightly closed. Get rid of any unused medication after the expiration date. To get rid of medications that are no longer needed or have expired: -Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location. -If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put it in the trash, empty the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible: -Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat -Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue -Red or dark brown urine, pain or trouble when passing urine, passing frequent amounts of urine Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome): -Nausea -Upset stomach

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions: -Dehydrated -Kidney disease -Liver disease -An unusual or allergic reaction to methenamine, tartrazine dye, other medications, foods, dyes, or preservatives -Pregnant or trying to get pregnant -Breast-feeding

What may interact with this medication?

Do not take this medication with any of the following: -Sulfa medications This medication may also interact with the following: -Acetazolamide -Antacids -Methazolamide -Sodium bicarbonate

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Tell your care team if your symptoms do not improve or if you get new symptoms. You will need to be on a special diet while taking this medication. Ask your care team how many glasses of water or other fluids to drink each day. Also, ask which foods to include and which to avoid to help keep your urine acidic. Your urine must be acidic for this medication to work.