Making It Easier to Read Prescriptions

Sig: I tab po qid pc & hs

Unless you have a medical background, that bunch of letters probably looks like gobbledygook. In fact, it's several abbreviations for Latin terms used on prescriptions (see chart), in this case telling the pharmacist, "Label the container for this patient's medication with the following instructions: Take one tablet 4 times a day, after meals and at bedtime."

But if some health professionals get their way, prescriptions may soon be easier to read--and therefore safer, since improved readability helps prevent medication mix-ups.

In separate efforts, the Food and Drug Administration and the American Medical Association recently urged medication prescribers to take new precautions with prescriptions.

Patients should take precautions, too, says Thomas McGinnis, R.Ph., associate director for pharmacy affairs at FDA. "If the directions written on a prescription seem confusing, ask your doctor or pharmacist to explain, until you fully understand how to take the medication."

The Rx

The Drug Enforcement Administration requires that prescriptions for controlled substances (drugs regulated by the Federal Controlled Substances Act) state the patient's name and address, date, name of the prescribed drug, dosage strength and form (such as 10-milligram tablets), amount to be dispensed, directions for use, number of allowed refills, and the prescriber's name, address, DEA registration number, and signature.

States may make additional requirements. And they regulate the information on other prescriptions.

Since September 1993, for instance, all Texas prescriptions have had to include the intended use of the drug, unless the prescriber decides this inclusion is not in the patient's best interest.

"At the same time, we strengthened the confidentiality portion of our statute," says Steve Morse, R.Ph., assistant director of compliance with the Texas State Board of Pharmacy, in Austin. "The law makes it very clear that pharmacists may not share usage information except as the patient directs, or with other health-care professionals when the pharmacist determines that passing this information on would be in the best interest of the patient, or with certain regulators, such as DEA, as required by law."

The Institute for Safe Medication Practices, in Warminster, Pa., also advocates putting the intended use on prescriptions, says pharmacist Michael Cohen, president of the institute. Many prescribers agree with this practice, Cohen says, while others argue against it. A number of states already require the use to be on drug orders for patients in long-term care facilities, he says.

"There's no question in my mind," Cohen says, "that if the doctor generally included the drug's use on the prescription, most drug name mix-ups that occur would never happen."

Look-Alike Names

Mix-ups of drugs whose names look alike in handwriting or sound alike have also been a concern to FDA, which has received numerous reports. Jerry Phillips and other colleagues on FDA's Medication Error Subcommittee began tracking this type of medication error in June of 1992.

"We review each report," Phillips says, "and, if warranted, we may call for the manufacturer to change a product's labeling and packaging, or even its name."

Examples of look-alike names and the approximate number of reports are:

  • Norvasc (amiodipine besylate) for high blood pressure, and Navane (thiothixene) for psychosis, 35 reports

  • Levoxine (levothyroxine) for low thyroid, and Lanoxin (digoxin) for heart failure, 25 reports

  • Prilosec (omeprazole) for duodenal ulcer, and Prozac (fluoxetine) for depression, 12 reports.

In the February 1995 FDA Medical Bulletin, the agency advised printing or typing prescriptions for drugs with look-alike names. "It's the handwritten or verbal orders that have been misinterpreted," Phillips says. Including the diagnosis on these prescriptions also could help prevent mix-ups, he says.

At FDA's request, Levoxine's manufacturer changed the name to Levoxyl. Also at FDA's request, Prilosec's name was changed in 1990 from Losec, which was being confused with the diuretic Lasix (furosemide).

In addition, some doctors today may be able to send prescriptions directly to pharmacies by computer, bypassing handwritten prescribing.

More Clarifying

The American Medical Association, at its annual meeting in 1994, recommended ways to make prescription writing clearer.

AMA's recommendations include:

  • If handwriting is illegible, use a computerized medication order system, if available. Otherwise, print or type prescriptions.

  • Write out instructions rather than use ambiguous abbreviations. (For example, write "daily" rather than "qd," an abbreviated Latin term for "every day," which could be misinterpreted as "qid," meaning "4 times a day," or "od," meaning "right eye.")

  • Avoid vague instructions, such as "take as directed."

  • Use the USAN-approved generic drug name, official name, or trademarked name if a specific product is required, rather than a locally coined name or unestablished abbreviated drug name. (For example, use "didanosine," the generic name of an AIDS drug, or its trade name, "Videx," instead of the abbreviation "DDI." USAN stands for United States Adopted Names, a nonproprietary designation for any compound used as a drug, established by negotiation between the manufacturer and the USAN Council.)

  • Avoid apothecary or chemical symbols, such as "K," the chemical symbol for potassium.

  • Use a leading "0" in decimals expressing less than one, as in "0.5 mL" (milliliter), but never an ending "0," as in "5.0 mL."

  • Avoid decimals when possible. (For example, prescribe "500 mg" [milligrams], rather than "0.5 g" [grams].)

  • Spell out the word "units" rather than write "u."

  • Use the metric system.

When verbal orders are necessary, AMA recommends that they be fully, clearly and articulately dictated, and then read back by the person receiving the order. (For example, say "three times daily," rather than the Latin abbreviation "tid.")

While Latin terms such as "Sig," for signa ("write") or signetur ("let it be labeled"), are still commonly seen on prescriptions, prescribers who follow the new recommendations may soon retire some of these terms and otherwise clarify their drug orders. "Let it be labeled correctly" is the expected result.

Dixie Farley is a staff writer for FDA Consumer.

Prescription Symbols

Latin served a good purpose on prescriptions when they were first written in the 1400s. Spread widely by Roman soldiers and traders, Latin was the main language of western Europe for hundreds of years. It was unlikely to change, because it was a "dead" language, and it was unlikely to be misinterpreted, because it was exact in its meaning. Of course, the patients who didn't know Latin probably didn't have the vaguest idea what they were taking.

The only part of a prescription where Latin appears today, however, is in the directions for taking the drug. This use has become a kind of medical shorthand. (See chart.) Some of these abbreviated terms have the potential to cause medication errors because they look so similar in handwriting, so their use is on the decline.

Where does the "Rx" for "prescription" come from? Its origins are given variously as an abbreviation of the Latin word "recipe," meaning "take," or as a representation of the astrological sign of Jupiter. This sign was placed on ancient prescriptions to invoke that deity's blessing on the medicine to help the person get well. More recently, the cross at the end of the "R" has been explained as a substitute period.

Common Latin Rx Terms
ante cibumacbefore meals
bis in diebidtwice a day
hora somnihsat bedtime
oculus dexterodright eye
oculus sinisterosleft eye
per ospoby mouth
post cibumpcafter meals
pro re nataprnas needed
quaque 3 horaq 3 hevery 3 hours
quaque dieqdevery day
quater in dieqid4 times a day
ter in dietid3 times a day