[Prescription errors in chemotherapy]

To describe and analyse the role of the pharmacy department in detecting errors in the prescription of cytostatic drugs.

A retrospective study was carried out over a two year period (2003-2004), which reviewed the errors detected by pharmacists in chemotherapy prescriptions. Medication errors were classified according to the system published by Otero et al. in the paper OErrores de medicaci-n: estandarizaci-n de la terminolog a y clasificaci-nO (Medication errors: standardizing the terminology and taxonomy).

During the period analysed, 43,188 doses of parenteral cytostatic drugs were prepared for the treatment of 3,959 patients. A total of 135 errors were detected (3.1/1,000 preparations). Errors were distributed as follows: incorrect dose (38.5%), drug omission (21.5%), incorrect drug (11.1%), frequency error and incorrect treatment duration (9.6% each), incorrect patient (7.4%), incorrect administration rate (1.5%) and incorrect administration route (0.7%). All of the errors would be classified with a B level of seriousness, since they were resolved in the pharmacy department before dispensing the drugs. At least 66 of these could be classified as potential adverse drug events. Furthermore, 11 cases of incorrect reductions in doses and 12 cases of omissions of cytostatic drugs were detected and these errors could lead to a possible reduced treatment efficiency.

Despite the low incidence of errors detected in chemotherapy prescriptions, their potential seriousness gives the pharmaceutical validation process a key role in improving safety for patients.