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 | — | Once a week |
The number-pattern shorthand
Alongside the Latin abbreviations, many Indian prescriptions use a simple three-number code for morning–afternoon–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.