Methenamine

Name: Methenamine Drug Interactions
Creator: Dr. Brian Staiger, PharmD, BCPS

2 interactions

Also sold as: Hiprex Hiprex® Urex Urex®

About 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; a… Read the full Methenamine drug information page →

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated Jun 30, 2026 · Editorial policy · Data sources

Sources: FDA prescribing information (Structured Product Labeling), the published literature cited in each entry, DDInter 2.0 (a major open-access drug-interaction database), and legacy DrugBank interaction data distributed by the NIH's RxNav service (decommissioned in 2024) — analyzed and reviewed by our pharmacist team. How we build this library →

Most serious with: Acetazolamide Furosemide Injection

2 Contraindicated

All (2) Contraindicated (2)

Contraindicated

Methenamine Acetazolamide Diamox® Sequels® An increased risk of insoluble precipitate with formaldehyde in the urine Details Methenamine Furosemide Injection Disal An increased risk of insoluble precipitate with formaldehyde in the urine Details

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Educational information only, not medical advice. Always confirm interactions with your pharmacist or prescriber before making any change to your medications.