PRN, the abbreviation of Pro re nata in latin, means as the circumstance arises or in the circumstance. It is commonly used in medicine to signify a medication that should be taken only when needed, as opposed to medications that should be taken strictly at a given time with a given dosage. What are common PRN medications? How do you interpret the time on PRN Medication Prescription?

PRN Medication

PRN medications can either be over the counter medications or prescribed medications. The decision of when to administer the drug depends on the caregiver, nurse or the patient's prerogative. Such administration of medication is not meant to imply, and should never allow for, exceeding a given daily dosage.

Common PRN medications

PRN medication(s) may fall into any drug classification, the following are common (but not limited to) PRN medications:

• Analgesics (medications for pain, like Oxycodone, Tylenol or Acetaminophen)
• Anti-inflammatory drugs such as Advil or Ibuprofen 
• Hypnotics or sedatives (medications for sleep such as Lorazepam, Zolipidem or Ambien)
• Medications used for breathing problems such as Albuterol or Proventil
• Medications used for digestive problems like constipation and heartburn (such as Senna or Pepcid)

How to Understand the Interval of Taking PRN Medicines

Some people might get confused about the definition of PRN, especially when it comes to the time of taking the medicine.

For example, if you have a PRN order for Tylenol 80mg Tab PRN Q2hrs, which means the interval should be 2 hours. However, with PRN, you don’t need to give the patient the medicine every 2 hours. If they decline to take the medicine at the two hour mark, but want it later, you can give them the medication using the time as the new start time for the two hour requirement.

However, you should bear in mind that with certain conditions like pain management pills, taking the pills at regular intervals is optimal for best results.

Watch a video for basic knowledge of the medication, the meaning of PRN medication, as well as other medication types: