What do OD, BD, TDS, SOS, HS mean on your prescription? Complete guide to medical abbreviations used in prescriptions.
Always confirm with your doctor
Abbreviations can vary between countries and hospitals. Always verify with your prescribing doctor or pharmacist if unsure.
Take the medicine once a day, preferably at the same time each day.
Take the medicine two times a day, usually morning and evening, at equal intervals.
Take the medicine three times a day, ideally every 8 hours (morning, afternoon, night).
Take the medicine four times a day, usually every 6 hours.
Take the medicine only when you need it — when symptoms occur. Do not take regularly.
Take as required based on symptoms. Similar to SOS but may have a minimum interval between doses.
Take or administer the medicine immediately — this is urgent.
Take the medicine at night before going to sleep.
Take the medicine 30 minutes before eating food.
Take the medicine after eating food, usually within 30 minutes of a meal.
Take the medicine in the morning.
Take the medicine in the evening.
Do not eat or drink anything — usually before surgery or certain tests.
Take the medicine first thing in the morning before eating.
Take the medicine after having breakfast.
Take the medicine by mouth — oral route.
Injection given under the skin using a small needle.
Injection given into the muscle using a longer needle.
Injection or infusion given directly into the vein.
A small volume IV infusion connected to a running IV line.
Apply directly on the skin surface.
Place under the tongue — dissolves quickly for fast action.
Breathe in through mouth — for respiratory medicines.
Ophthalmic — for eye drops. OU = both eyes, OD = right, OS = left.
Stop taking this medicine — do not continue.
Take the medicine with food.
Can also mean half dose or half tablet when used with dose instructions.
Solid oral dosage form — swallow with water.
Oral dosage form in a gelatin shell — swallow whole.
Liquid oral medicine — measure dose carefully.
Medicine given by injection — SC, IM, or IV.
Take the medicine for a total of 5 days.
Take the medicine for 8 weeks.
Take the medicine for 3 months.
Complete the entire prescribed course — do not stop early even if you feel better.
A small initial dose given to check for allergic reaction before giving the full dose.
Blood tests or clinical monitoring needed while on this medicine.
Do not stop suddenly — gradually reduce the dose over days/weeks under supervision.
Avoid taking this medicine with specific foods or other medicines.
Take the medicine when stomach is empty — usually 1 hour before or 2 hours after food.
Always take this medicine with food to prevent stomach upset or improve absorption.
Take the tablet/capsule whole — do not crush, chew, or break.
Use the sugar-free version — important for diabetic patients.
| Abbreviation | Full Form | Meaning | Example |
|---|---|---|---|
| OD | Once Daily (Omne Die) | Take the medicine once a day, preferably at the same time each day | Telma 40 mg OD — take one tablet every morning |
| BD | Twice Daily (Bis Die) | Take the medicine two times a day, usually morning and evening, at equal intervals | Pantocid 40 mg BD — take one tablet before breakfast and one before dinner |
| TDS | Three Times Daily (Ter Die Sumendus) | Take the medicine three times a day, ideally every 8 hours (morning, afternoon, night) | Sevelamer 800 mg TDS — take with each meal |
| SOS | As Needed (Si Opus Sit) | Take the medicine only when you need it — when symptoms occur | Crocin 650 mg SOS — take only when you have fever or pain |
| HS | At Bedtime (Hora Somni) | Take the medicine at night before going to sleep | Clonazepam 0.25 mg HS — take at bedtime for sleep |
| AC | Before Meals (Ante Cibum) | Take the medicine 30 minutes before eating food | Pantocid 40 mg AC — take 30 min before breakfast |
| PC | After Meals (Post Cibum) | Take the medicine after eating food, usually within 30 minutes of a meal | Wysolone PC — take after breakfast |
| IV | Intravenous | Injection or infusion given directly into the vein | Inj. Meropenem 1 gm IV in 100 ml NS over 1 hr |
| SC | Subcutaneous | Injection given under the skin using a small needle | Inj. Erythropoietin 10,000 units SC |
| IM | Intramuscular | Injection given into the muscle using a longer needle | Inj. Vitocofol 2 ml IM |
