Prescription abbreviations, decoded
5 minute read
Open a prescription from almost any Indian doctor and you'll see it: a string of capital letters next to each medicine: OD, BD, 1-0-1, HS, SOS. It's a shorthand doctors and pharmacists learn in training, and it saves them time. It also means a family reading the same slip has no idea whether "TDS" means three times a day or three days total.
This guide only decodes the shorthand: what each abbreviation means, and nothing else. It doesn't tell you what to do about a medicine, when to start or stop one, or how to adjust a dose. Any of those questions goes to your parent's doctor or pharmacist, every time.
How often a medicine is taken
| Abbreviation | Full form (Latin origin) | What it means |
|---|---|---|
| OD | omne in die | Once a day |
| BD (or BID) | bis in die | Twice a day |
| TDS (or TID) | ter die sumendum | Three times a day |
| QID | quater in die | Four times a day |
| HS | hora somni | At bedtime |
| SOS | si opus sit | When needed, not on a fixed schedule |
| STAT | statim | Immediately, as a one-off dose |
| OW | n/a | Once a week |
The number-pattern shorthand
Alongside the Latin abbreviations, many Indian prescriptions use a simple three-number code for morning, afternoon and evening/night, separated by hyphens:
- 1-0-1: one dose in the morning, none at midday, one at night.
- 1-1-1: one dose morning, afternoon and night.
- 1-0-0: one dose in the morning only.
- 0-0-1: one dose at night only.
- ½-0-½: half a dose morning and night. Common for tablets that are scored down the middle for splitting.
A "0" in the pattern isn't a typo. It's telling you that slot is deliberately skipped.
Route and form
| Abbreviation | What it means |
|---|---|
| PO | By mouth (per os) |
| SL | Under the tongue (sublingual) |
| SC | Under the skin (subcutaneous injection) |
| IM | Into the muscle (intramuscular injection) |
| IV | Into a vein (intravenous) |
| PR | Rectally |
| Top. | Applied to the skin (topical) |
Timing relative to food
| Abbreviation | What it means |
|---|---|
| AC (ante cibum) | Before food |
| PC (post cibum) | After food |
| C.F. / c.m. | With food / with meals |
| Empty stomach | Before eating anything, usually first thing in the morning |
Quantity and duration
| Abbreviation | What it means |
|---|---|
| Tab / Cap | Tablet / capsule |
| mg / mcg / g | Milligram / microgram / gram |
| ml | Millilitre |
| x 5 days / x 7 days | For five days / seven days, then stop unless told otherwise |
| Qty | The total number of tablets or the total volume being dispensed |
| Rpt | Repeat: the prescription can be refilled |
A note on why this matters
None of this shorthand is standardised the way a nutrition label is. Two doctors can write the same instruction two different ways, and a chemist filling the prescription is trained to read both. That's exactly why a family trying to keep track of several medicines from several doctors ends up needing to translate each slip by hand, which is the problem PURE Care exists to take off your plate: we read every prescription, our care team checks it, and you see one clear list in plain English instead of a page of shorthand.
If anything on a prescription is unclear or looks unusual, the right next step is always the same: ask the prescribing doctor or your pharmacist. This guide explains terminology; it doesn't replace either of them.