How long must symptoms persist after administering a PRN before contacting a healthcare professional?

Symptoms must persist for a duration of 72 hours after administering a PRN (pro re nata, or as needed) medication before contacting a healthcare professional. This time frame is significant because it allows for a reasonable period to evaluate the effectiveness of the medication and see if the symptoms resolve on their own. Immediate contact with a healthcare provider may be necessary in acute situations or if symptoms worsen, but generally, observing the patient's response for 72 hours provides helpful information about the condition's progression and allows for a more informed discussion with a healthcare professional. The longer observational window can help avoid unnecessary healthcare visits for conditions that may resolve with time or further dosage adjustments.