Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
Quick facts
- How it is given
- oral
- Type
- human prescription drug
- RxNorm ID
- 992150
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
INDICATIONS AND USAGE To reduce the development of drug-resistant bacteria and maintain the effectiveness of Methenamine Hippurate Tablets and other antibacterial drugs, Methenamine Hippurate Tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. Methenamine Hippurate Tablets are indicated for prophylactic or suppressive treatment of frequently recurring urinary tract infections when long-term therapy is considered necessary. This drug should only be used after eradication of the infection by other appropriate antimicrobial agents.
About this medicine
DESCRIPTION Methenamine Hippurate Tablets are a urinary tract antiseptic drug. Each white, scored tablet contains methenamine hippurate 1g (see HOW SUPPLIED). Methenamine Hippurate Tablets also contain: magnesium stearate, povidone and saccharin sodium. Chemically, methenamine hippurate is the hippuric acid salt of methenamine (hexamethylenetetramine). Structural formula: C 15 H 21 N 5 O 3 Molecular Weight 319.37 Methenamine structural formula
Who should not take it
CONTRAINDICATIONS Methenamine Hippurate Tablets are contraindicated in patients with renal insufficiency, severe hepatic insufficiency, or severe dehydration. It should not be used as the sole therapeutic agent in acute parenchymal infections causing systemic symptoms.
Warnings
WARNINGS Patients with pre-existing hepatic insufficiency may suffer adverse effects from the small amounts of ammonia and formaldehyde that are produced. The classical syndrome of acute hepatic failure may be evoked in these patients.
Reported side effects
ADVERSE REACTIONS Adverse effects of Methenamine Hippurate Tablets have been reported in fewer than 3.5% of patients treated. These reactions have included the following, in decreasing order of frequency: nausea, vomiting and rarely pruritus, rash, dysuria. Children have received Methenamine Hippurate Tablets at the recommended dosages as a prophylactic/suppressive regimen after initial treatment of acute episodes of pyuria. Side effects were encountered in only 1.1% of these children.
Interactions with other medicines
Drug Interactions: The concomitant administration of methenamine hippurate and sulfamethizole or sulfathiazole is liable to result in the formation of a precipitate in the urine.
If too much is taken
OVERDOSAGE Immediately after ingestion of an overdose, further absorption of the drug may be minimized by inducing vomiting or by gastric lavage, followed by administration of activated charcoal. Fluids, either oral or parenteral, should be forced to tolerance.
Before you take anything new
Tell your pharmacist or doctor about every medicine you take — including ones bought without a prescription, herbal products and supplements. Interactions are one of the most common avoidable causes of harm from medicines, and a pharmacist can check your full list in a couple of minutes.
This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 17 November 2024. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.