The Nurse Is Preparing to Administer Methenamine (Hiprex) to a Patient

The nurse is preparing to administer methenamine (Hiprex) to a patient who has pyelonephritis. The nurse understands that methenamine use is associated with the potential side effect of crystalluria. Which of the following would increase the risk of crystalluria?

A) Restrict fluid intake.
B) Darkening of the urine.
C) Frequent ingestion of cranberry juice.
D) Combination therapy with a sulfonamide.