How Do I Read My Physician's Prescription?

To the untrained eye, prescriptions can be pretty hard to decipher. The various notations used on prescriptions have very specific meanings.

Let's consider a hypothetical prescription for penicillin written as follows:

• Rx Pen VK 250/ml 1 bottle
• iiss ml qid X 7d

Here is what the notation on this prescription means:

• The medication is Penicillin VK and your doctor ordered one 250 milliliter (ml) bottle, which is about 8 ounces.
• The "ii" means 2 and "ss" means 1/2 which translates to 2 1/2 ml, or 1/2 teaspoon.
• The qidX7d means 4 times each day for 7 days.

Using the information noted on this prescription, the pharmacist will provide a bottle of Penicillin VK with label directions indicating that 1/2 teaspoon of the medication should be taken four times each day for seven days.

It is important to learn how to decipher your physician’s prescription. Doing so will help you avoid a medication error and give you better insight into your treatment. You can always ask your pharmacist to interpret a prescription for you. Physicians may use various abbreviations combining Latin and English, and your pharmacist may be familiar with your physician's style.

Here are some other notations commonly found on prescriptions:

• PO means orally
• QD means once a day
• BID means twice a day
• QHS means before bed
• Q4H means every 4 hours
• QOD means every other day
• PRN means as needed
• q.t.t. means drops
• OD means in the right eye (think eye drops)
• OS means in the left eye (think eye drops)
• OU means in both eyes (think eye drops)
• a.c. means before a meal
• p.c. means after a meal
• IM means intramuscularly (injection)
• Subq means subcutaneous (injection)
• IV means intravenous (injection)

You may see a symbol on your script that looks like a "T" with a dot at the top of it. This abbreviation means one pill. There may be one to 4 T's with dots at the top of them signifying one to 4 pills.

On a final note, if you ever have a question about notation made on a prescription please feel free to ask your physician or pharmacist. Please keep in mind that pharmacists are skilled healthcare professionals who are very able to answer your questions regarding medication dosages, effects, and adverse effects. You have a right to be involved and be informed in all aspects of your medical care including understanding what's written on your prescriptions.

Content edited by Naveed Saleh, MD, MS, on 1/30/2016.