Methenamine
- Atc Codes:J01XX05
- CAS Codes:100-97-0
- PHARMGKB ID:100-97-0
Table of contents
- Brand Names
- Drug Combinations
- Chemistry
- Pharmacologic Category
- Mechanism of Action
- Therapeutic Use
- Pregnancy and Lactation Implications
- Contraindications
- Warnings and Precautions
- Adverse Reactions
- Drug Interactions
- Nutrition/Nutraceutical Interactions
- Dosage
- Pharmacokinetics and Pharmacodynamics
- Special Considerations
Brand Names
Europe
Denmark: Haiprex; Finland: Hipeksal, Hiprex; Germany: Urotractan; Luxembourg: Hiprex; Poland: Urosal; Sweden: Hiprex; UK: Hiprex.
North America
Canada: Mandelamine; USA: Hiprex, Methenamine, Urex.
Latin America
Mexico: Biorán.
Asia
Japan: Hexamine.
Drug combinations
Methenamine, Charcoal (Activated), and Magnesium Citrate
Chemistry
Methenamine: C~6~H~12~N~4~. Mw: 140.19. (1) 1,3,5,7-Tetraazatricyclo[3.3.1.1^3,7^]decane; (2) Hexamethylenetetramine. CAS-100-97-0.
Pharmacologic Category
Urinary Anti-infectives. (ATC-Code: J01XX05).
Mechanism of action
Methenamine is hydrolyzed to formaldehyde and ammonia in acidic urine; formaldehyde has nonspecific bactericidal action. Other components, hippuric acid or mandelic acid, aid in maintaining urine acidity and may aid in suppressing bacteria.
Therapeutic use
Prophylaxis or suppression of recurrent urinary tract infections. Urinary tract discomfort secondary to hypermotility.
Pregnancy and lactiation implications
Adverse events observed in some animal studies. Methenamine considered to be «probably safe» for use during pregnancy. Use not recommended during lactation.
Unlabeled use
Contraindications
Hypersensitivity to methenamine or any component of the formulation. Severe dehydration, renal insufficiency, severe hepatic insufficiency. Concurrent treatment with sulfonamides.
Warnings and precautions
Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea and pseudomembranous colitis. Use with caution in gout, or in hepatic impairment. Contraindicated in severe impairment. Use with caution in the elderly. Some preparations might contain tartrazine dye (might cause allergic reactions). Should not be used to treat infections outside the lower urinary tract.