About methenamine hippurate
Urinary antiseptic
Used for
- Prevention of recurrent urinary tract infections after active infection is treated.
Usual adult dose
1 g twice daily.
Usual dose in children
Not routinely used in children; specialist dosing depends on age and product guidance.
Common side effects
- Nausea or stomach upset
- Rash or itching
- Painful or frequent urination
Important warnings
- Not for treating an active urinary infection.
- Avoid in severe kidney or liver disease, or severe dehydration.
- Avoid with sulfonamide antibiotics and urine-alkalinizing medicines.
- Works best when urine is acidic.
Pregnancy
Use only when a clinician considers it necessary; safety evidence is limited, especially early in pregnancy.
Breastfeeding
Use only after clinical review; information on safety during breastfeeding is limited.
Interactions
- Sulfonamide antibiotics may form crystals with methenamine in urine.
- Urine-alkalinizing medicines, such as potassium citrate, can reduce its effect.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.