Methenamine

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 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.

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.

<p></p> <p></p> <p></p> <p>Methenamine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

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upset stomach</li>
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vomiting</li>
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diarrhea</li>
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stomach cramps</li>
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loss of appetite</li></ul></p> <p></p> <p>If you experience any of the following symptoms, call your doctor immediately:

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skin rash</li>
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hives</li>
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itching (allergic reaction)</li></ul>If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at <a href='http://www.fda.gov/Safety/MedWatch'>http://www.fda.gov/Safety/MedWatch</a>] or by phone [1-800-332-1088].</p>

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.

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.