Final answer:
Phenazopyridine (Pyridium) may cause the urine to change to an orange-red color (option C) , which is a harmless side effect, but patients should be aware of it to avoid undue worry.
Step-by-step explanation:
A patient taking phenazopyridine (Pyridium), which is a urinary tract analgesic, should be cautioned that her urine may change to an orange-red color. Phenazopyridine is used to relieve symptoms caused by irritation of the lower urinary tract such as pain, burning, and the feeling of needing to urinate urgently or frequently. This medication can cause the urine to turn an orange or red color, which can be alarming to patients if they are not advised about this potential side effect beforehand.
It is important to note that this discoloration of the urine is a harmless side effect and not indicative of harm. However, if the urine becomes dark brown or there is a change in urine clarity, this could indicate a more serious condition and the patient should consult their healthcare provider.