Which statement indicates that a client understands the reason for the need to drink approximately 3 liters of fluid while taking trimethoprim-sulfamethoxazole (TMP-SMZ)?

Question

1. "I need to drink a lot of fluids to keep my bladder full."
2. "I need to drink a lot of fluids to flush the bacteria out of my bladder."
3. "I need to drink a lot of fluids to prevent crystals from forming in my urine."
4. "I need to drink a lot of fluids to prevent an allergy from developing."

Answer 1

Correct Answer: 3
Rationale 1: Drinking extra fluids will create more of a need to void, but keeping the bladder full is not necessary or wanted.
Rationale 2: Fluids do not flush the bacteria out of the system. The sulfonamides are responsible for slowing the bacterial growth of the uropathogens.
Rationale 3: Clients must drink extra fluids to prevent crystalluria that can potentially obstruct the kidneys or urethra.
Rationale 4: Drinking extra fluids does not prevent a hypersensitivity reaction.
Global Rationale: Sulfonamides have a low solubility, which may cause crystalluria, crystals that form in the urine and potentially obstruct the kidneys or ureters. The risk is higher in dehydrated patients and when urine pH is abnormally low. To decrease the possibility of crystalluria, fluids in amounts up to 3,000 mL per day should be encouraged to achieve a urinary output of 1,500 mL in 24 hours. It is not necessary to keep the bladder full and drinking fluids will not prevent a hypersensitivity reaction. Fluids do not flush the bacteria out of the system.