Urex Side Effects
Generic Name: methenamine
Note: This document contains side effect information about methenamine. Some of the dosage forms listed on this page may not apply to the brand name Urex.
For the Consumer
Applies to methenamine: oral suspension, oral tablet, oral tablet enteric coated
Along with its needed effects, methenamine (the active ingredient contained in Urex) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking methenamine:Less common
- Skin rash
- Blood in urine
- lower back pain
- pain or burning while urinating
Some side effects of methenamine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:Less common
- Nausea and vomiting
For Healthcare Professionals
Applies to methenamine: compounding powder, oral suspension, oral tablet
This drug was generally well tolerated. Minor side effects have been reported in less than 3.5% of patients and were reversible when the drug was stopped.[Ref]
Uncommon (0.1% to 1%): Rash, pruritus
Frequency not reported: Generalized skin rash[Ref]
Uncommon (0.1% to 1%): Gastric irritation
Frequency not reported: Nausea, vomiting, upset stomach, stomatitis, gastrointestinal disturbances, diarrhea, abdominal cramping[Ref]
High doses have been associated with albuminuria, gross hematuria, bladder irritation, and painful/frequent micturition.[Ref]
Uncommon (0.1% to 1%): Bladder irritation
Frequency not reported: Dysuria, hematuria, urinary frequency, albuminuria[Ref]
Frequency not reported: Elevated AST, elevated ALT[Ref]
Frequency not reported: Hypersensitivity reactions[Ref]
Frequency not reported: Anorexia
Frequency not reported: Anterior uveitis[Ref]
1. "Product Information. Hiprex (methenamine)." Hoechst Marion-Roussel Inc, Kansas City, MO.
2. Cerner Multum, Inc. "Australian Product Information." O 0
3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
4. Gleckman R, Alvarez S, Joubert D, Matthews S "Drug therapy reviews: methenamine mandelate and methenamine hippurate." Am J Hosp Pharm 36 (1979): 1509-12
5. "Product Information. Mandelamine (methenamine)." Parke-Davis, Morris Plains, NJ.
6. Australian Drug Evaluation Committee "Adverse effects of drugs commonly used in the treatment of urinary tract infection." Med J Aust 1 (1972): 435-8
7. Brumfitt W, Hamilton-Miller J, Gargan R, Cooper J, Smith GW "Long-term prophylaxis of urinary infections in women: comparative trial of trimethoprim, methenamine hippurate and topical povidone-iodine." J Urol 130 (1983): 1110-4
8. Brumfitt W, Cooper J, Hamilton-Miller J "Prevention of recurrent urinary infections in women: a comparative trial between nitrofurantoin and methenamine hippurate." J Urol 126 (1981): 71-4
9. Kolker RJ "Medication-induced bilateral anterior uveitis." Arch Ophthalmol 109 (1991): 1343
Some side effects of Urex may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
More about Urex (methenamine)
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Images
- Drug Interactions
- Support Group
- 0 Reviews – Add your own review/rating
- Generic Availability
- Drug class: urinary anti-infectives
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