METHENAMINE (meth EN a meen) is used to prevent urinary tract infections due to bacteria. It is not used to treat an active infection. It will not work for colds, flu, or other viral infections.
This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.
COMMON BRAND NAME(S): Hiprex, Urex
They need to know if you have any of these conditions:
•an unusual or allergic reaction to methenamine, tartrazine dye, other medicines, foods, dyes, or preservatives
•pregnant or trying to get pregnant
Take this medicine by mouth with a full glass of water. Follow the directions on the prescription label. Do not crush or chew. Take your medicine at regular intervals. Do not take your medicine more often than directed. Take all of your medicine as directed even if you think you are better. Do not skip doses or stop your medicine early.
Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for children as young as 6 years old 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.
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.
Do not take this medicine with any of the following medications:
This medicine may also interact with the following medications:
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.
Tell your doctor or health care professional if your symptoms do not improve or if you get new symptoms.
You will need to be on a special diet while taking this medicine. Ask your health care professional 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 medicine to work.
Side effects that you should report to your doctor or health care professional as soon as possible:
•allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
•bladder pain, irritation
•lower back pain
•painful, frequent urination
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
•loss of appetite
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.
Keep out of the reach of children.
Store between 15 and 30 degrees C (59 and 86 degrees F). Keep container tightly closed. Throw away any unused medicine after the expiration date.
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.
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Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.