Deciphering Your Prescription

When your doctor gives you a prescription for medication, you should always read it and make sure you understand the dosage instructions before you leave the office.

Knowing what your prescription says before you have it filled can help you make sure that what you receive from the pharmacy is consistent with what your doctor ordered.

The illegibility of doctor’s handwriting is well established. If you have trouble reading what your doctor has written, ask him to read it for you. Here are some commonly used abbreviations that will help you understand what is written.

  • q written lower case with a line over it means “every”
  • q am means “every morning”
  • q pm means “every evening”
  • HS means literally “hour of sleep,” or in other words, “bed time”
  • c written lower case with a line over it means “with”
  • c food means “with food,” or “with meals”
  • prn means “as needed”
  • q4h means “every four hours”
  • q12h means “every 12 hours”
  • qid means “four times a day”
  • tid means “three times a day”
  • bid means “twice a day”
  • po means “by mouth”
  • sig indicates the instructions for usage that are to be written on the prescription packaging label
  • “as directed” means according to the directions your doctor gave you—when you see this, make sure you understand those directions before you leave your doctor’s office. Write them down if necessary, especially if you aren’t feeling well.