Methenamine/Sodium Salicylate/Benzoic Acid Uses/Indications Dosage Side effects- DrugsAce

DEA Class; OTC

Common Brand Names; Cystex

Methenamine: Hydrolyzed in acidic urine to ammonia and formaldehyde, which are bactericidal agents; does not convert to formaldehyde in serum.

Sodium salicylate: Analgesic

Benzoic acid: Elicits weak antifungal and antibacterial properties; also helps acidify urine

Use only after eradication of UTI by other appropriate antibiotic

Methenamine: Indicated for prophylaxis/suppression for chronic recurring UTIs when long-term therapy is required

Sodium salicylate: Analgesic

Benzoic acid: Elicits weak antifungal and antibacterial properties; also helps acidify urine

Hypersensitivity to methenamine or tartrazine (FD&C Yellow No. 5)
Renal or severe hepatic insufficiency
Concurrent sulfonamides or acetazolamide may form insoluble precipitate in urine

Large doses may cause bladder irritation, urinary frequency, albuminuria, and hematuria
Maintain acidic pH of urine, especially when treating urea-splitting organisms (eg, Proteus, Pseudomonas)
Monitor LFTs, especially with history of liver impairment
Safe use not established during pregnancy, especially 1st and 2nd trimester
May precipitate uric acid stones in patients with gout

Anemia
GI malabsorption
History of peptic ulcers
Gout
Hepatic disease
Hypochlorhydria, Hypoprothrombinemia, Renal impairment, Renal calculi, Thyrotoxicosis, Vitamin K deficiency

Pregnancy Category: C

Lactation: methenamine is excreted in human milk; caution advised, risk to infant cannot be ruled out

Adults

Urinary Tract Infection Prophylaxis

2 tablets PO q12hr

Administer with meals and at bedtime

Methenamine/sodium salicylate/benzoic acid

tablet