How to read a doctor’s prescription: OD, BD, TDS and other abbreviations explained
What OD, BD, TDS, QID, HS, SOS, AC and PC mean on an Indian prescription, how to read 1-0-1, and the questions to ask before you leave the clinic.
By the MedMate team5 min read
Quick answer
OD means once a day, BD twice a day, TDS three times a day and QID four times a day. HS means at bedtime, SOS means only if needed, AC means before food and PC means after food. A line like 1-0-1 means one dose in the morning, none in the afternoon and one at night.
You are back home from the clinic, the strip is on the table, and the prescription says “Tab. X 650 mg, 1-0-1 × 5 days, PC”. The doctor explained it, but that was twenty minutes and one auto ride ago. If this has happened to you, you are in very good company.
Indian prescriptions use a short set of Latin abbreviations and a number code. Once you know them, most prescriptions take seconds to read.
How often to take it
- OD (once daily): one dose a day, usually at the same time each day.
- BD or BID (twice daily): morning and night, roughly 12 hours apart.
- TDS or TID (three times daily): morning, afternoon and night.
- QID or QDS (four times daily): spread across the day, roughly every 6 hours while awake.
- HS: at bedtime.
- SOS or PRN: only if needed, for example for pain or fever. Not a regular dose.
- Stat: right away, once.
Before or after food
- AC (ante cibum): before food, usually 30 minutes before a meal.
- PC (post cibum): after food.
- Empty stomach: usually an hour before or two hours after eating.
The 1-0-1 code
Many doctors in India write doses as three numbers for morning, afternoon and night. 1-0-1 means one in the morning and one at night. 1-1-1 means three times a day. 0-0-1 means only at night. ½-0-½ means half a tablet morning and night. “× 5 days” or “5/7” means keep going for five days, even if you feel better on day two.
Words for the medicine itself
- Tab tablet, Cap capsule, Syp or Syr syrup, Inj injection, Gtt drops, Oint ointment.
- Rx at the top simply means “prescription”.
- Strength is written next to the name, such as 500 mg, or 5 ml for syrups. Always match the strength on the pack to the strength on the prescription.
Five questions to ask before you leave the clinic
- What is each medicine for?
- How long should I take it, and can I stop when I feel better?
- Before or after food?
- What should I do if I miss a dose?
- Is there anything I should avoid, like alcohol, driving or other medicines?
If you still can’t read it
Ask the pharmacist. Reading prescriptions is part of their job, and a good pharmacist would much rather explain than have you guess. When MedMate launches, the pharmacist will check your uploaded prescription before packing, and the app’s medicine schedule will turn “1-0-1” into reminders at the right times.
This article is general information, not medical advice. If you are worried about your health or someone else’s, speak to a doctor.
Questions
What does BD mean on a prescription?
BD means twice a day, usually morning and night, about 12 hours apart.
What does 1-0-1 mean on a prescription?
One dose in the morning, none in the afternoon and one at night.
What does SOS mean on a prescription?
Take it only if you need it, for example when you have pain or fever. It is not a regular dose.
What is the difference between AC and PC?
AC means before food and PC means after food.
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