Methenamine Dosage

Usual Adult Dose for Cystitis

Hippurate: 1 g orally twice a day (morning and night)
Mandelate: 1 g orally 4 times a day (after each meal and at bedtime)

Uses:
-Hippurate: For prophylactic or suppressive treatment of frequently recurring urinary tract infections (UTIs) when long-term therapy deemed necessary
-Mandelate: For the suppression or elimination of bacteriuria associated with pyelonephritis, cystitis, and other chronic UTIs; for infected residual urine due to some neurologic diseases

Usual Adult Dose for Cystitis Prophylaxis

Hippurate: 1 g orally twice a day (morning and night)
Mandelate: 1 g orally 4 times a day (after each meal and at bedtime)

Uses:
-Hippurate: For prophylactic or suppressive treatment of frequently recurring urinary tract infections (UTIs) when long-term therapy deemed necessary
-Mandelate: For the suppression or elimination of bacteriuria associated with pyelonephritis, cystitis, and other chronic UTIs; for infected residual urine due to some neurologic diseases

Usual Adult Dose for Pyelonephritis

Hippurate: 1 g orally twice a day (morning and night)
Mandelate: 1 g orally 4 times a day (after each meal and at bedtime)

Uses:
-Hippurate: For prophylactic or suppressive treatment of frequently recurring urinary tract infections (UTIs) when long-term therapy deemed necessary
-Mandelate: For the suppression or elimination of bacteriuria associated with pyelonephritis, cystitis, and other chronic UTIs; for infected residual urine due to some neurologic diseases

Usual Adult Dose for Urinary Tract Infection

Hippurate: 1 g orally twice a day (morning and night)
Mandelate: 1 g orally 4 times a day (after each meal and at bedtime)

Uses:
-Hippurate: For prophylactic or suppressive treatment of frequently recurring urinary tract infections (UTIs) when long-term therapy deemed necessary
-Mandelate: For the suppression or elimination of bacteriuria associated with pyelonephritis, cystitis, and other chronic UTIs; for infected residual urine due to some neurologic diseases

Usual Pediatric Dose for Cystitis

Hippurate:
6 to 12 years: 0.5 to 1 g orally twice a day (morning and night)
13 years or older: 1 g orally twice a day (morning and night)

Mandelate:
6 to 12 years: 0.5 g orally 4 times a day (after each meal and at bedtime)
13 years or older: 1 g orally 4 times a day (after each meal and at bedtime)

Uses:
-Hippurate: For prophylactic or suppressive treatment of frequently recurring UTIs when long-term therapy deemed necessary
-Mandelate: For the suppression or elimination of bacteriuria associated with pyelonephritis, cystitis, and other chronic UTIs; for infected residual urine due to some neurologic diseases

Usual Pediatric Dose for Cystitis Prophylaxis

Hippurate:
6 to 12 years: 0.5 to 1 g orally twice a day (morning and night)
13 years or older: 1 g orally twice a day (morning and night)

Mandelate:
6 to 12 years: 0.5 g orally 4 times a day (after each meal and at bedtime)
13 years or older: 1 g orally 4 times a day (after each meal and at bedtime)

Uses:
-Hippurate: For prophylactic or suppressive treatment of frequently recurring UTIs when long-term therapy deemed necessary
-Mandelate: For the suppression or elimination of bacteriuria associated with pyelonephritis, cystitis, and other chronic UTIs; for infected residual urine due to some neurologic diseases

Usual Pediatric Dose for Pyelonephritis

Hippurate:
6 to 12 years: 0.5 to 1 g orally twice a day (morning and night)
13 years or older: 1 g orally twice a day (morning and night)

Mandelate:
6 to 12 years: 0.5 g orally 4 times a day (after each meal and at bedtime)
13 years or older: 1 g orally 4 times a day (after each meal and at bedtime)

Uses:
-Hippurate: For prophylactic or suppressive treatment of frequently recurring UTIs when long-term therapy deemed necessary
-Mandelate: For the suppression or elimination of bacteriuria associated with pyelonephritis, cystitis, and other chronic UTIs; for infected residual urine due to some neurologic diseases

Usual Pediatric Dose for Urinary Tract Infection

Hippurate:
6 to 12 years: 0.5 to 1 g orally twice a day (morning and night)
13 years or older: 1 g orally twice a day (morning and night)

Mandelate:
6 to 12 years: 0.5 g orally 4 times a day (after each meal and at bedtime)
13 years or older: 1 g orally 4 times a day (after each meal and at bedtime)

Uses:
-Hippurate: For prophylactic or suppressive treatment of frequently recurring UTIs when long-term therapy deemed necessary
-Mandelate: For the suppression or elimination of bacteriuria associated with pyelonephritis, cystitis, and other chronic UTIs; for infected residual urine due to some neurologic diseases

Renal Dose Adjustments

Renal dysfunction: Contraindicated

Liver Dose Adjustments

Severe liver dysfunction: Contraindicated

Precautions

Safety and efficacy have not been established in patients younger than 6 years.

Consult WARNINGS section for additional precautions.

Dialysis

Renal dysfunction: Contraindicated

Other Comments

Administration advice:
-Hippurate: Only use after infection eradicated by other appropriate antibacterial drugs
-Restrict alkalinizing foods and drugs; antibacterial activity of this drug is greater in acid urine (maximum efficacy occurs up to pH 5.5).
-Start supplemental acidification of the urine if needed based on urinary pH and clinical response.

Storage requirements:
-Store at 25C (77F); excursions permitted to 15C to 30C (59F to 86F).
-Mandelate: Store in tight, light-resistant bottle

General:
-Mandelate: When used as recommended, this drug is especially suitable for long-term therapy due to its safety and because no resistance to formaldehyde develops; pathogens resistant to other antibacterial agents may respond to this drug.
-Mandelate prophylactic use rationale: As urine is a good culture medium for many urinary pathogens, inoculation by a few organisms (relapse or reinfection) may cause bacteriuria in susceptible patients. The rationale for managing recurring UTI (bacteriuria) is to change urine from growth-supporting to growth-inhibiting medium; data available showing long-term use of this drug can prevent bacteriuria recurrence in patients with chronic pyelonephritis.
-Mandelate therapeutic use rationale: This drug helps sterilize urine; if underlying pathologic conditions prevent sterilization by any means, it can help suppress bacteriuria. This drug should not be used alone for acute parenchymal infections causing systemic symptoms (e.g., chills, fever); thorough diagnostic investigation as a part of overall UTI management recommended with use of this drug.

Monitoring:
-Genitourinary: Urinary pH; urine cultures
-Hepatic: Liver function studies (periodically during therapy)

Patient advice:
-To ensure an acidic pH, restrict or avoid milk products and antacids containing sodium carbonate or bicarbonate.
-Avoid missing doses and complete the entire course of therapy.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer