Prescription Abbreviations Including Sig

Healthcare providers use prescription abbreviations based on Latin words. These abbreviations tell your pharmacist two things:

  • Which medication to give you
  • Directions on how to use that medication

Knowing how to read medical shorthand will help you understand your prescriptions. When you know what medication you will be receiving, you will be able to ask informed questions.

This article will help you learn to read your prescriptions. It will also discuss how understanding your prescriptions can help prevent medical errors.

Doctor writing a prescription

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Prevent a Prescription Medical Error

It is important to understand your prescriptions. This can make a medical error less likely. 

It is possible, for example, that your pharmacist could make a mistake. If your healthcare provider's handwriting is not easy to read, you may have to wait longer for your medication. Worse, you could be given the wrong dose or the wrong directions.

Pharmacies can receive prescriptions a few different ways. Your healthcare provider might give you a handwritten or printed prescription to take to the pharmacy yourself. Your prescription may also be faxed or electronically submitted.

Many healthcare providers' offices now use electronic prescribing. This is where your healthcare provider submits your prescription directly to the pharmacy electronically. Some states require electronic prescribing.

Electronic prescriptions help prevent medical errors that can be caused by hard-to-read handwriting.

Electronic prescriptions are especially important for controlled substances. Controlled substances are drugs that are restricted by the government because of their potential for abuse. This includes opioids, powerful pain relievers that can be addictive.

Ask to see a printout of your prescription before leaving your healthcare provider's office. Check your prescription first to make sure it is filled correctly. If you think there is an error, you can tell the pharmacist or call your healthcare provider.

If you do not understand what your prescription says, ask for help. Your healthcare provider or another healthcare provider in the office can answer your questions. This could help you detect and prevent an error.

Quick Tip

Ask your healthcare provider to include your condition on the prescription—for example, not just "take once a day," but "take once a day for high cholesterol." This can help you keep track of your medications and what each one is for.

What Your Prescription Looks Like

Handwritten prescriptions are usually written on a pre-printed paper. The paper will show your healthcare provider's name, address, and phone number.

You may also see numbers such as a Drug Enforcement Administration (DEA) number, which allows your healthcare provider to prescribe controlled substances. These numbers may appear on the top or bottom of the paper.

There will also be space for your name and address, your age, the date, and the healthcare provider's signature. In the blank area, your healthcare provider will write the following directions:

  • Medication name
  • Medication dose
  • How often to take the medication
  • When to take the medication
  • How to take the medication

The prescription will also indicate how much medicine the pharmacist should give you. It will also include the number of times you can refill the prescription.

Common Medical Abbreviations

Your healthcare provider may use different abbreviations or symbols. If you do not understand them, ask your healthcare provider or pharmacist for help.

The table below includes some commonly used prescription abbreviations. You can also find an alphabetical list of abbreviations at ResourcePharm.

Medical Abbreviations
How Often to Take Your Medication  
ad lib freely, as needed
bid twice a day
prn as needed
q every
q3h every 3 hours
q4h every 4 hours
qd every day
qid four times a day
qod every other day
tid three times a day
When to Take Your Medication  
ac before meals
hs at bedtime
int between meals
pc after meals
How Much Medication to Take  
cap capsule
gtt drops
i, ii, iii, or iiii number of doses (1, 2, 3, or 4)
mg milligrams
mL milliliters
ss one-half
tab tablet
tbsp tablespoon (15 mL)
tsp teaspoon (5 mL)
How to Use Your Medication  
ad right ear
al left ear
c or o with
od right eye
os left eye
ou both eyes
po by mouth
s or ø without
sl sublingual
top apply topically

DAW—Dispense As Written

Medications have brand names and generic names. Your healthcare provider may use either on your prescription. For example, sertraline is the generic name for the brand Zoloft. Zoloft is a medication often prescribed to treat depression.

In many states, pharmacists can give you a generic medication even if your healthcare provider writes a prescription for the brand name version. In some cases, though, your healthcare provider may write "DAW" on your prescription.

DAW stands for "dispense as written." This means the pharmacist cannot legally give you a generic medication instead of the brand name one.

DAW-1 means the healthcare provider is requiring the brand name drug. DAW-2 means the patient requested the brand name drug.

Generic drugs are typically less expensive than brand name drugs. Because of this, some insurance plans will penalize you for a DAW prescription. For example, you may have to pay the cost difference between the generic and the brand name drug.

Recap

"DAW" means your pharmacist can not substitute the generic drug for the brand name. Some insurance plans may require you to pay the cost difference for a brand name drug. Talk with your healthcare provider if you have questions about a DAW on your prescription.

Sig—Instructions That Go On the Prescription Label

"Sig" is short for the Latin "signetur." This means "let it be labeled." You may see this on your prescription just before the directions.

"Sig" tells the pharmacy what they should include on the drug's label. This ensures you will know how and when to take the medication.

Prescription Examples

For a diagnosis of high cholesterol:

  • Zocor 10 mg: This is the name of the medication and the dose.
  • Sig: i po qhs: Your instructions are to take one pill, by mouth, at bedtime.
  • Dispense #90: You will be given 90 pills, enough for about three months.
  • Refill 0 times: Your healthcare provider has indicated no refills. This is usually because you will need to see your healthcare provider before continuing the medication. Tests will help determine if the medication is working or you need a different dose.
  • DAW left blank: Your pharmacist will most likely give you simvastatin. This is the generic version of Zocor.

For a diagnosis of type 2 diabetes:

  • Glucophage 500 mg: This is the name of the medication and the dose.
  • Sig: i po bid pc: Your instructions are to take one pill, by mouth, twice each day, after meals. This means you should take this medication right after breakfast and right after dinner.
  • Dispense #180: You will be given 180 pills, enough for three months.
  • Refill 3 times: Your healthcare provider has indicated three refills. This is enough medication for one year. This may mean your diabetes is "stable" and well-controlled on this medication.
  • DAW left blank: Your pharmacist will most likely give you metformin. This is the generic version of Glucophage.

For a diagnosis of high blood pressure:

  • Diovan 40 mg: This is the name of the medication and the dose.
  • Sig: i po qd: Your instructions are to take one pill, by mouth, once each day. You most likely can take this medication either before or after a meal since your healthcare provider did not say otherwise.
  • Dispense #90: You will be given 90 pills, enough for about three months.
  • Refill 0 times: Your healthcare provider has indicated no refills. This is usually because you will need to see your healthcare provider before continuing the medication. Tests will help determine if the medication is working or you need a different dose.
  • DAW left blank: Your pharmacist will likely give you valsartan. This is the generic version of Diovan.

Summary

Understanding your prescription can help you prevent a medical error. Always ask your healthcare provider for a copy of your prescription. Use the table above to interpret your prescription.

Make sure your prescription label matches your healthcare provider's instructions. If you have questions, ask your healthcare provider or pharmacist.

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4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Pharmacy Times. A technician's guide to pharmacy abbreviations.

  2. Fallaize R, Dovey G, Woolf S. Prescription legibility: bigger might actually be better. Postgrad Med J. 2018;94(1117):617-620. doi:10.1136/postgradmedj-2018-136010.

  3. Achar S, Sinha N, Norcross W. The adoption and increased use of electronic prescribing of controlled substancesJ Med Regul. 2021;107(2):8–16. doi:10.30770/2572-1852-107.2.8

  4. Shrank W, Liberman JN, Fischer MA, et al. The consequences of requesting “dispense as written.” Am J Med. 2011;124(4):309-317. doi:10.1016/j.amjmed.2010.11.020

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