Adult

Methenamine Hippurate

General Information

Restricted Formulary antimicrobial: Use in accordance with Trust guidelines

AWaRe antibiotic classification: 'Other'. Use as per guidelines. 

 

Can be prescribed by Primary care: See Oxfordshire Clinical Commissioning Group formulary for more details

Dosage

Renal impairment

eGFR ml/min/1.73m2 oral dose
10 or more 1g BD
Less than 10   AVOID - contra-indicated

 

Hepatic impairment

AVOID - manufacturers advise that use is contraindicated in hepatic dysfunction

Notable interactions

  • Avoid concurrent use with:
    • sulphonamides,
    • co-trimoxazole,
    • alkalinising agents (e.g. potassium citrate),
    • acetazolamide

Pregnancy and breastfeeding

Pregnancy 

AVOID. Contact pharmacy for advice.

Breastfeeding

Excreted in trace amounts in breast milk. Manufacturers advise that methenamine can be used in breastfeeding mothers.  

Additional information

  • Perform urine cultures and urinalysis prior to initiating and ensure pH is acidic. 
  • 6 monthly reviews of use are required.
  • Methenamine may affect the determination of steroids, catecholamines, 5-hydroxyindole acetic acid from urine, giving false results.

References

Editorial Information

Next review date: 02 Apr 2028