Answer to Question 1
ANS: A, C, E
Creatinine clearance levels should be monitored, because if the levels are too low, toxicity may occur. Nitrofurantoin imparts a harmless brown color to the urine, and it can cause multiple neurologic effects, such as headache, vertigo, and drowsiness.
Nitrofurantoin should be taken with meals to minimize gastrointestinal (GI) upset (nausea, vomiting and diarrhea).
The patient will experience diarrhea, not constipation.
Answer to Question 2
ANS: B
Nalidixic acid can intensify the effects of warfarin, and a reduction in the warfarin dosage may be needed.
Nalidix acid increases warfarin levels, thus it would be inappropriate to increase the dose.
Concurrent administration of nalidixic acid and warfarin does not affect nalidixic levels.