BID
Medical abbreviation · Prescription
| Stands for | Bis in die (twice a day) |
|---|---|
| Categories | Medical |
BID stands for Bis in die (twice a day), a prescription abbreviation.
Frequency meaning two doses in a 24-hour day, usually about 12 hours apart. Many hospitals schedule BID doses at fixed times such as 0900 and 2100, while outpatients are typically told to take them with breakfast and dinner.
Example: Metformin 500 mg PO BID with meals; increase to 1,000 mg BID after one week if tolerated.
Usage notes
Latin "bis in die" means "twice in a day". Also written b.i.d. or bid; the UK equivalent is "bd" (bis die). BID is not the same as q12h: q12h implies strict 12-hour spacing around the clock, which matters for antibiotics and anticoagulants, whereas BID allows flexibility around meals and sleep. ISMP has reported "BT" (bedtime) being misread as BID.
Related abbreviations
More prescription abbreviations
- aa – Ana (of each)
- AC – Ante cibum (before meals)
- ACHS – Ante cibum et hora somni (before meals and at bedtime)
- ad lib. – Ad libitum (at one's pleasure)
- ATC – Around the clock
- bd – Bis die (twice a day)
- BIW – Twice a week
- BT – Bedtime
- cc – Cubic centimeter
- c̄ – Cum (with)
- D/C – Discontinue
- DAW – Dispense as written
See all 77 prescription abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.