By Erin DostalThe Daily Northwestern
Take one teaspoon orally three times daily. Do not take with food. Shake well.
While these instructions are commonplace on prescription drug labels, nearly half of all patients may be misinterpreting them, according to a recent study by Michael Wolf, an assistant professor in general internal medicine at Feinberg School of Medicine.
“Some of these very simple instructions that patients may completely ignore … in some instances could cause severe problems,” Wolf said.
The study was conducted between the summers of 2004 and 2005 in conjunction with research at Emory, Harvard and Louisiana State universities.
Researchers studied adult patients at federally qualified health centers in Illinois, Louisiana and Michigan. Researchers gave each patient five drugs and asked them to explain how they would take the medicine.
The process helped researchers determine if patients with low literacy levels had difficulty interpreting labels.
All participants were given a reading test and were reviewed by three physicians.
Of the 395 patients in the study, 46 percent misinterpreted one or more of the labels presented to them. Those with a sixth-grade reading level or lower, as well as patients taking three or more drugs at a time, were more likely to make a mistake, said Wolf, who first presented his results in March to the Food and Drug Administration.
In the study, participants of all reading levels made mistakes interpreting labels.
“I think this is a really important question,” said SESP senior Genna Cohen, who trained to do research with Wolf. “I think that it’s a really well-designed study.”
“Take two tablets twice daily” was the statement participants were most likely to misunderstand. Of patients with low literacy levels, 30 percent correctly interpreted the phrase to mean taking four tablets daily, instead of two.
Other patients misread “teaspoon” as “tablespoon,” which could lead a person to take three times the recommended dosage of a drug.
Wolf said he is concerned about contradictions on drug labeling because many patients will stop taking a drug if they don’t understand how to use it.
Wolf recalled a prescription label for a drug his brother was taking for acid reflux. The label had three instructions: “do not chew or crush,” “you can crush the medicine and sprinkle it on your food” and “do not take with food,” Wolf said.
Not crushing medicine can be important for drugs that release over time. For some drugs, such as those for hypertension, crushing medication before ingestion can give a patient acute hypotension instead.
“These are actual chemical agents that you’re taking into your body,” Wolf said. “Taking medicine is such a common experience for most of us that I don’t think that the (necessary) level of attention is placed on (medications).”
The FDA has explicit regulations for wording on over-the-counter drugs because they can be accessed without the advice of a physician, said Mary Kremzner, deputy director of the Division of Drug Information at the FDA.
“A prescription label is not written for the layman,” Kremzner said. “We don’t write for the fifth-grade reading level.”
As a possible solution, Wolf hopes the FDA will place the same regulations on prescription labels as those on over-the-counter drugs. Wolf said that because the physician is not responsible for administering the drug to the patient, the labels should be written for the layman, not the physician.
Many drugs come with medication guides written to the level of the patient, Kremzner said. But there are no FDA regulations for the wording on the labels themselves.
“If policy changes as a result of the study I think that would be really wonderful,” Cohen said. “It would be a really significant contribution.”
Wolf is optimistic that policy changes will come in the future.
“It seems like something we can actually fix,” Wolf said.
Reach Erin Dostal at [email protected].
