Physicians use medical "shorthand" to write patients' prescriptions.
Some of these abbreviations are:
- p.o. - taken orally or "by mouth"
- p.r.n. - as needed
- q.h.s. - at bedtime
- b.i.d. - twice daily
- t.i.d. - three times daily
- q.i.d. - four times daily
- #xx - quantity per fill
Example: Trazodone 50 mg #30 one to two p.o. q. h.s. p.r.n. sleep - would translate as "Fill thirty (30) trazodone hydrochloride 50 mg tablets, take one to two pills at bedtime as needed for sleep".
NOTE: It should be noted that these abbreviations appear to be different in the UK (and likely other countries).