list of medical abbreviations: latin abbreviations list of medical abbreviations: latin abbreviations the main discussion of these abbreviations in the context of drug prescriptions and other medical prescriptions is at list of abbreviations used in medical prescriptions. some of these abbreviations are best not used, as marked and explained here. abbrev. meaning latin (or neo-latin) origin a.c. before meals ante cibum a.d., ad, ad right ear auris dextra a.m., am, am morning ante meridiem nocte every night omne nocte a.s., as, as left ear auris sinistra a.u., au, au both ears together or each ear aures unitas or auris uterque b.d.s, bds, bds 2 times a day bis die sumendum b.i.d., bid, bid twice a day / twice daily bis in die gtt., gtts drop(s) gutta(e) h., h hour hora qhs, h.s., hs at bedtime or half strength quaque hora somni ii two tablets duos doses iii three tablets trēs doses n.p.o., npo, npo nothing by mouth / not by oral administration nil per os o.d., od, od right eye once a day (united kingdom) oculus dexter omne in die o.s., os, os left eye oculus sinister o.u., ou, ou both eyes oculus uterque p.c. after food post cibum p.m., pm, pm afternoon or evening post meridiem p.o., po, po by mouth / oral administration per os / nonstandard form per orem p.r., pr, pr rectally / rectal administration per rectum p.r.n., prn, prn as needed, (also pertactin - a key antigen of ac.pertussis vaccine) pro re nata q. every quaque q.1.h., q1h every hour quaque hora q.2.h., q2h every 2 hours quaque secunda hora q.4.h., q4h every 4 hours quaque quarta hora q.6.h., q6h every 6 hours quaque sexta hora q.8.h., q8h every 8 hours quaque octava hora q.a.m., qam, qam every morning quaque ante meridiem q.d., qd every day / daily quaque die q.h.s., qhs every night at bedtime quaque hora somni q.d.s, qds, qds 4 times a day quater die sumendum q.i.d, qid 4 times a day quater in die q.h., qh every hour, hourly quaque hora q.o.d., qod every other day / alternate days quaque altera die q.p.m., qpm, qpm every afternoon or evening quaque post meridiem q.s., qs a sufficient quantity (enough) quantum sufficiat q.wk. also qw weekly (once a week) quaque week rx, rx, ℞ prescription recipe sig., s. directions signa stat. immediately, with no delay, now statim t.i.d., tid, tid 3 times a day ter in die t.d.s., tds, tds take by mouth 3 times a day ter die sumendus u.d., ud as directed ut dictum . this article is issued from wikipedia. the text is licensed under creative commons - attribution - sharealike. additional terms may apply for the media files.