What it means
A dosing schedule of two doses a day, usually about 12 hours apart, such as 0900 and 2100. Many orders and drug labels still use the abbreviation BID (or bid). It is different from "every 12 hours" (q12h), where the timing is strict, which matters for drugs that must keep an even level in the blood, such as some antibiotics.
In a chart
"Metoprolol tartrate 25 mg PO twice daily."
At a glance
| Abbreviations | BID, b.i.d.; ISMP lists BIW (twice a week) as error-prone because it is misread as twice a day |
|---|---|
| Spanish | dos veces al día |
| Also written | twice a day, BID |
Related terms
PRN
As needed: an order for a drug or treatment to be given only when the client needs it, within set limits.