This grade answers one narrow question: how strong is the public evidence and safety record behind this drug, and how clean is its money trail and court record? It is not a verdict on whether the drug is right for you.
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.
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 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.
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.
Source: FDA SPL label for Methenamine Hippurate (Alvogen Inc.), effective 20241117. Full label on DailyMed.
These are counts of reports people filed, not rates of harm. Anyone can file one, and nobody checks whether the drug was the cause. Millions of doses are taken for every report sent, so the useful part is how this drug compares with the average across all drugs.
| 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
|---|---|---|---|---|---|---|---|
| 238 | 224 | 202 | 219 | 268 | 264 | 355 | 210 |
924 reports blaming this drug for every million Medicare prescriptions filled, which is 0.3× the typical drug on this site. (826 reports in 2024–2026, against 893,800 Medicare fills in one year. This is the one number here that accounts for how many people take the drug.)
Source: the FDA's Adverse Event Reporting System (FAERS). Reports are voluntary and unverified. Drugs that are prescribed a lot, in the news, or in lawsuits attract more reports, so the percentages are compared with the whole database to correct for that partly, not fully.
Counts measure how much evidence exists and how transparent it is, not how big the benefit is. For that, ask your prescriber: if 100 people like me took this, how many would get better because of it, and how many would be harmed? (Doctors call these the "number needed to treat" and "number needed to harm.") It differs by condition and is the number drug ads leave out. Sources: PubMed, ClinicalTrials.gov.
In 2024, drug companies reported $0 in payments to US physicians and hospitals tied to this drug across 0 transactions.
No pending federal MDL names this drug or its brands.
Not named in any federal pharmaceutical settlement of $100M or more on record.
Sources: CMS Open Payments (Sunshine Act); Judicial Panel on Multidistrict Litigation pending docket list; DOJ settlements as tabulated on Wikipedia with links to the primary record. State-court and individual suits are not included.
| Product | Fills | $/fill |
|---|---|---|
| Methenamine Hippurate | 887,845 | $69 |
| Methenamine Mandelate | 5,955 | $106 |
No same-class alternatives found in RxClass.