Famous author Mark Twain wrote, in 1864, that doctors should "discard abbreviations… to avoid the possibility of mistakes." We agree! A prescription for medicine should not be a mystery to understand. Many abbreviations and words in prescriptions come from Latin. We'd like to help by explaining each part of a typical prescription and translating some of the Latin abbreviations into English words.
Download: Learn to read your prescription
Rollover letters A-K to for an explanation of each part of a prescription.
|Common abbreviation||Latin words that make up the abbreviation||The meaning on your prescription|
|ac||ante cibum||before meals|
|bid||bis in die||twice a day|
|gtt||gutta||drop (as in 1 drop, 2 drops, and so on)|
|hs||hora somni||at bedtime|
|od*||oculus dexter||right eye|
|os||oculus sinister||left eye|
|po||per os||by mouth|
|pc||post cibum||after meals|
|prn||pro re nata||as needed|
|qd**||quaque die||every day, or daily|
|qid||quarter in die||4 times a day|
|tid||ter in die||3 times a day|
*Sometimes, od is used to mean "once daily." The word "daily" should be used instead to prevent mistakes.
**The abbreviation qd is considered dangerous. It should not be used because it has been mistaken as qid frequently. This mistake has led to serious harm, since people took once-a-day medicine four times each day.