Parents May Err With ALL Kids' Home Chemotherapy

SEATTLE, Aug. 14 -- For children with acute lymphoblastic leukemia (ALL), the multidrug, multidose regimen of home oral chemotherapy may be too complicated for some parents to master, according to a study here.

When asked to demonstrate how their child's chemotherapy drugs were to be given, nearly 20% of parents made at least one mistake, reported James A. Taylor, M.D., of the University of Washington, and colleagues.

The majority of mistakes were not clinically significant, but a few were potentially life-threatening, the researchers reported online today in Cancer.

Medication errors in the hospital setting have been well-studied, but errors for outpatient pediatric oncology patients-who generally receive their chemotherapy from a parent or caregiver with no medical training-have received little attention, the investigators said.

"Because these medications are toxic and have narrow therapeutic windows, the results of an error may be disastrous," they wrote.

The study involved 69 children (ages one to 18) treated for ALL. At a regularly scheduled clinic visit, parents were asked to bring in all of their child's chemotherapy medication and show how much of each was to be given. Parents were also asked about the timing of each dose. The children were usually on two or three different drugs.

A medication error occurred in nearly 10% of chemotherapeutic agents prescribed for the patients. Thirteen of the 69 parents made a mistake with least one of the medications so that mistakes occurred in 18.8% of the children. Some parents made mistakes with two medications, brining the error total up to 17.

Of these 17 mistakes, 12 were errors of timing and five were errors of dose.

Four of the mistakes were potentially serious. Three children were not receiving a monthly dose of corticosteroid, which placed them at increased risk for relapse. One child was receiving a 57% overdose of Purinethol (mercaptopurine) which could have led to life-threatening infection, the investigators said.

Two of the five medicines in the study had especially high error rates. The error rate for dexamethasone was 17% and the rate for prednisone was 20%, compared with error rates of 0% to 7% for the other three drugs.

The higher error rates for these medicines was likely because their regimen requires two different daily doses, the authors said. Both of these corticosteroids are sold under a variety of U.S. brand names.

There were no pharmacy-dispensing errors in this study.

Parents who didn't speak English did not make significantly more errors than those who did (P=.54). Nor did parents with a high school education or less make more errors than college-educated parents (P=.34).

"Although parents of children receiving outpatient oral chemotherapy may be highly invested in properly administering the prescribed drugs, the number of required medications and complexity of dosing may be challenging for parents without medical training," the authors said.

Parents must often calculate the correct dose based on their child's size, a situation that is ripe for error, the authors said. One way to fix this problem would be for hospitals to use a computerized physician order entry (CPOE) system that automatically calculates the correct dose for parents, the authors suggested.

"Perhaps more important, consideration should be given to modifying treatment protocols such that a given child receives the same morning and evening dose of corticosteroid medication and/or designing regimens so that patients are not prescribed two different strength tablets of dexamethasone or prednisone," they said.

Parental errors might also be reduced by using calendars showing the specific drugs and dosages to be given on each day of the month or pill boxes containing the exact medications to be given during a specific time period, the authors suggested.

If future, larger studies bear out the nearly 20% error rate, it may mean that significant numbers of children are at risk for toxicity or reduced efficacy of their drug regimen, the authors warned.

However, because this was only a two-month study, it could not show that the medication errors contributed to long-term treatment failure, they added.

Finally, because of the study's small size and its focus on children with acute lymphoblastic leukemia, it is not clear if the results would apply to other types of pediatric oncology patients, the authors said.