hiprex and Azulfidine Interactions

Interactions between hiprex(methenamine) and Azulfidine (sulfasalazine)

methenamine and sulfasalazine (Moderate Drug-Drug)

GENERALLY AVOID: Methenamine produces an acidic urine, which may predispose patients to sulfonamide-induced crystalluria.

MANAGEMENT: The interaction is not expected with more water-soluble sulfonamides such as sulfisoxazole. An alkalinizing agent should not be added because this may render methenamine less effective.