Uses
Methenamine, an antibiotic, eliminates bacteria that cause urinary tract infections. It usually is used on a long-term basis to treat chronic infections and to prevent the recurrence of infections. Antibiotics will not work for colds, flu, or other viral infections.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
Side Effects Of Methenamine
Methenamine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- upset stomach
- vomiting
- diarrhea
- stomach cramps
- loss of appetite
If you experience any of the following symptoms, call your doctor immediately:
- skin rash
- hives
- itching (allergic reaction)
Warnings & Precautions
Before taking methenamine:
- tell your doctor and pharmacist if you are allergic to methenamine, aspirin, tartrazine (a yellow dye in some processed foods and drugs), or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially antacids, sulfamethizole, diuretics (‘water pills’), and vitamins.
- tell your doctor if you have or have ever had kidney or liver disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking methenamine, call your doctor.
Methenamine Dosage
Methenamine comes as a tablet and a liquid to take by mouth. It usually is taken either two times a day (every 12 hours) or four times a day (after meals and at bedtime). Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take methenamine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Swallow the coated tablets whole. Do not crush or break them. Take the tablets with a full glass of water or with food. Shake the liquid well before each use to mix the drug evenly.
Other
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to methenamine.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Source
All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.
