Prescription abbreviations in India: OD, BD, TDS, HS, SOS and the rest

Prescription shorthand is a working language between the doctor and the chemist. It saves time on a busy OPD morning, and most of the time it is read the way it was meant. This page is a reference for both sides of the counter, and for doctors in their first years of practice: the abbreviations you will meet on Indian prescriptions, where each one comes from, what it means, and the few that have caused mistakes, some of them harmful, because they can be read two ways.

What do OD, BD, TDS and the other timing abbreviations mean?

These say how often, and sometimes when, to take a medicine. The Latin below is taken from the UK’s Patient.info prescribing guidance and a list from the US state of Minnesota.

You will also see English shorthand with no Latin behind it: BBF and ABF for before and after breakfast, ES for an empty stomach, and “x 5d” or “5d” for five days. BF deserves a second look: on its own it usually means before food, but in “after BF” it means breakfast. The number patterns themselves, such as 1-0-1 and ½-0-½, have a guide of their own.

Abbreviations for the form, the route and the side

The World Health Organization’s Guide to Good Prescribing explains that the R/ at the top comes from recipe, Latin for “take”, and the S (signa, “write”) marks the directions to be copied onto the label. The other Latin is from the Minnesota list. Around the medicines you will also see English shorthand for the notes: c/o (complains of), k/c/o (known case of), h/o (history of), Dx (diagnosis), Inv (investigations), Adv (advice) and F/U (follow-up).

Which abbreviations cause mistakes?

The ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations (2024 edition) collects shorthand that was reported to the US Institute for Safe Medication Practices after it was misread, in errors that harmed patients or could have. ISMP says none of it should be used anywhere: not in handwritten or electronic prescriptions, not on labels, not on screens. These are the entries most likely to appear on an Indian prescription, with two more from an Indian hospital’s own list:

The HS and BD rows come from the “never use” list in the study described below; the Minnesota list also warns that HS can mean half-strength. Six entries in the table (U, IU, QD, QOD, the trailing zero and the missing leading zero) are on the US Joint Commission’s “Do Not Use” list too, which ISMP marks on its own list. ISMP even prefers mL, with a capital L, to ml, so that the l can’t be taken for a 1.

Shortened drug names deserve a word. ISMP’s advice is to avoid abbreviating drug names entirely, and India’s 2002 ethics regulations already ask, in clause 1.5 as amended in 2016, for generic names written “legibly and preferably in capital letters”. PCM can stay in your head; PARACETAMOL goes on the paper.

Do these mistakes happen in Indian hospitals?

They do, and a short “never use” list helps, if only a little. A team from AIIMS New Delhi reviewed inpatient prescriptions at an apex tertiary care public hospital and found error-prone abbreviations at an incidence of 47.5%. They drew up a 12-item “never use” list from ISMP’s list and the Australian Commission on Safety and Quality in Health Care’s, put it up on posters in the wards and taught the doctors. The incidence fell to 43.6%, as the study reported in Current Drug Safety in 2023. The preprint’s tables show the commonest offenders: “Inj” for injection, BD for twice a day and OD for once daily. The fall was clear in medicine and surgery and close to nothing in paediatrics, and the authors ask for more: fuller teaching, pocket cards and a policy that forbids these abbreviations.

Legible doesn’t mean understood, either. At a tertiary care government hospital in Kolkata, 96% of 380 patients’ prescriptions were legible, yet only 40% of the patients had a good grasp of how often to take their medicines. Every participant could read English and Bengali. The authors suggest the reason: frequency abbreviations such as BD “are not explained to the patients”, while the number of days “is written as a number, which they understood better”. The abbreviation that a chemist reads at a glance can still be a puzzle at home.

How to write it so nobody has to guess

1. Say how often in words, or as a pattern with words: “1-0-1, morning and night” rather than BD alone. ISMP advises “daily” instead of OD or QD; if you keep OD, never leave it on its own: add the pattern, as in OD (1-0-0).
2. Put the eye and the ear in words on drops: “right eye”, “left eye”, “both eyes”.
3. Write the food instruction and the days in full: “after food, for 5 days”, “half an hour before breakfast”.
4. Give every SOS its limits: what it is for, the most in a day and the gap between doses. WHO’s Guide to Good Prescribing asks for the maximum dose and the minimum dose interval whenever a medicine is “as required”.
5. Write “units” in full, and micrograms as mcg (never µg); put a zero before a decimal point (0.5 mg) and never after one (1 mg, not 1.0 mg).
6. Name the day for weekly and alternate-day doses: “once a week, every Sunday”.
7. Add one line in the patient’s language. WHO’s guide prefers the local language to Latin and asks for the directions in lay language, without abbreviations or “as directed”. Our Hindi phrases for prescriptions are ready to copy.

If your hospital keeps an approved abbreviation list, put its never-use part where prescriptions are written, as the AIIMS team did. ISMP’s own advice is plain: if you use an uncommon or ambiguous abbreviation, define it.

Where DrMate Rx fits

DrMate Rx, our prescription pad, lets you keep typing the shorthand you already use and prints a complete line from it. Type pcm 650 1-0-1 5d af and the line prints as Tab PARACETAMOL 650 mg, with 1 tab, BD (1-0-1), after food and 5 days in their own columns and “Qty: 10 tabs” under it. Lower on the page, a line of Hindi for the patient reads “Paracetamol 650 mg: 1 गोली, दिन में दो बार, खाने के बाद, 5 दिन तक” (1 tablet, twice a day, after food, for 5 days). The paper never says “pcm”.

On eye drops, it reads OD as the right eye only when the line also says how often: moxicip e/d 1 drop qid od 7d is the right eye, four times a day, while latanoprost 1 drop od be names both eyes, so OD there is once a day. When the line could mean either, as in moxicip e/d 1 drop od 7d, it asks one question, “Is OD the right eye, or once a day?”, and never guesses. It also keeps BBF (before breakfast) apart from BF (before food). If you would rather talk than type, the doctor’s room drafts the prescription from the consultation for you to approve. Either way, the rules on what a prescription must show still apply, and the pad prints in that format.