Prescription Labels Decoded

Why can’t doctors use normal language? At least tell me how to take my prescriptions, right? Here is a brief decoder guide to doctor-speak on prescription labels.


qd (or qday): once daily (ask your doctor what time of day)

qam: once daily in the morning

qpm: once daily in the evening

qhs: once daily at bedtime

bid: twice daily (every twelve hours)

tid: three times per day (every eight hours)

qid: four times per day (every six hours)


prn: as needed for (don’t take it unless you really need it)

PO: by mouth

IM: intramuscular (given be injection deep into the muscle)

subcut: subcutaneous (given by skin prick needle just barely under the skin surface)


Read your label and/or ask your pharmacist if you should be taking it with food. Some medications won’t work if you take them on an empty stomach.

Many medications cannot be taken if you need to drive. For example, you will get a DUI if you take pain medications/narcotics and many anxiety medications/benzodiazepines and drive. You also must wait at least 8-12 hours after taking any sleeping medication before you drive the next day (even if you feel awake).

Many medications are dangerous if taken with alcohol. Read your label and ask your pharmacist.


Make sure and ask your doctor. Clarify it with them every time you see them. That’s what they are there for.


By Dr. Terra Caudill, MD, MS