Daily OTC Pearl: Cystex for Urinary Tract Infection

OTC/Lifestyle Pearl of the Day: Cystex

Indication: Cystex is used for urinary tract infection (UTI) prophylaxis.

Insight:

• Dosage: 162 mg/162.5 mg/32 mg
• Dosing: 2 tablets PO q12hr
  • Administer with meals and at bedtime.
  • Use only after eradication of UTI by other appropriate antibiotic.
• Ingredients:
  • 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.
• Adverse events: Dysuria, gastric upset, nausea, and rash.
• Warning: Methenamine is excreted in human milk; caution advised, risk to infant cannot be ruled out.
• Mechanism of action:
  • 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.

Sources:

Cystex (methenamine/sodium salicylate/benzoic acid) dosing, indications, interactions, adverse effects, and more. (medscape.com)