Final answer:
Evaluate the patient's symptoms and medical history to determine if taking an over-the-counter cold remedy is appropriate. If symptoms persist or worsen, it is advisable to consult a healthcare professional for further evaluation.
Step-by-step explanation:
When a patient asks whether it is OK to take an over-the-counter cold remedy, the appropriate response would be to evaluate the patient's symptoms and medical history to determine if the remedy is suitable. In the case of Barbara, the 19-year-old college student, her persistent cough and fever, along with feeling tired and weak, indicate that the over-the-counter cold medication she took did not work. It would be wise for her to consult a healthcare professional to explore other treatment options.