OD, BD, SOS: Decoding the Secret Language on Your Prescription
The average prescription in India contains at least three abbreviations that the patient receiving it has never been explained. The doctor writes them, the pharmacist reads them, and you the person whose body is going to receive this medication are left to guess what "BD x 5 days SOS" actually means.
This has been bothering me for years. You have a right to understand your own prescription. So let's go through the most common ones.
How Often to Take It
OD (Omni Die) Once daily. Usually specified as morning or night. If not specified, ask.
BD (Bis Die) Twice a day. Typically morning and evening, roughly 12 hours apart. The spacing matters for maintaining consistent drug levels in your bloodstream.
TID (Ter In Die) Three times a day. Usually morning, afternoon, and evening often aligned with meals if the medicine should be taken with food.
QID (Quater In Die) Four times a day. Every 6 hours. This one requires you to actually set alarms consistency in timing is usually important with QID medicines.
Special Instructions
SOS (Si Opus Sit) "If needed." This medicine should only be taken when you have the specific symptom (usually pain, nausea, or fever). Don't take it routinely it's for relief when needed.
AC (Ante Cibum) Before food. Usually 30 minutes before a meal. Some medicines work better or cause less irritation when taken on an empty stomach.
PC (Post Cibum) After food. Take this one with or after a meal. This usually means the medicine is harsh on the stomach lining or absorbs better with food.
HS (Hora Somni) At bedtime. The medicine works best, or causes drowsiness that's better experienced at night.
The Route and Duration
PO (Per Os) By mouth. Oral medication. This is usually implied but sometimes written explicitly when multiple routes are possible.
Stat Immediately. Take one dose right now. Usually seen on the first line of an antibiotic prescription or a painkiller when the doctor wants a loading dose to take effect quickly.
x 5/7 For 5 days. The "/ 7" refers to seven days in a week, so this is shorthand for a duration. Similarly, x 2/52 means two weeks (52 weeks in a year), and x 1/12 means one month (12 months in a year). Yes, it's confusing. Ask your pharmacist if you're unsure.
A Note About Asking Questions
You should never leave a pharmacy without understanding exactly when, how, and how long to take every medicine on your prescription. A good pharmacist will explain this without being asked. But if they don't, ask. It's not a bother. It's your health. And if any abbreviation on your prescription isn't in this list, look it up or ask never assume.