Background and Importance Chemotherapy errors represent a potentially serious risk of patient harm because of the narrow therapeutic window of antineoplastic and their high toxicity. Pharmaceutical validation aims to optimise chemotherapy treatment in order to obtain the best results for patients‘ health and to minimise potential prescription errors.

Aim and Objectives To describe the chemotherapy prescription errors of intravenous cytostatic detected during the pharmaceutical validation and the interventions made to avoid potential harm to the patient, helping prevent mistakes.

Material and Methods Observational, descriptive, retrospective study of chemotherapy prescribing errors detected by pharmaceutical validation that resulted in a prescription change in intravenous chemotherapy.

They were recorded between November 2020 to September 2021 and the programme used for prescribing and recording was OncoFarm.^®

The errors were classified into 10 groups: 1) Upper/lower dose <10%, 2) Upper dose >10%, 3) lower dose >10%, 4) Inappropriate cycle frequency, 5) Relevant interaction or adverse effect, 6) Dose adjustment or delay administration (renal and hepatic impairment, haematologic toxicity), 7) Incorrect protocol, 8) Missing drug, 9) Excess drug, 10) Others.

Results During the study period, 180 chemotherapy errors were detected among 53.243 doses of intravenous chemotherapy prepared in a hospital pharmacy for 2.944 patients (63% from oncology service, 32% haematology service, 3% urology service; 2% others). These errors detected through pharmaceutical prescription review induced changes in chemotherapy prescriptions: 88 in haematology prescriptions, 83 in oncology prescriptions, 6 in urology prescriptions and 3 in onco-haematology prescriptions.

Classification 6 Upper/lower dose <10%, 60 upper dose >10%, 7 lower dose >10%, 17 inappropriate cycle frequency, 4 relevant interaction or adverse effect, 14 dose adjustment or delay administration (renal and hepatic impairment, haematologic toxicity), 20 incorrect protocol, 12 missing drug, 18 excess drug, 22 others

The most common errors were attributed to error prescription of upper dose >10%, in 36% were carboplatin dose mistakes; and also errors in prescribing and protocol frequency.

Conclusion and Relevance Despite the number of detected chemotherapy errors does not represent a large volume in the total number of patients treated in almost two years, they led to a probable reduction in adverse drug events, toxicities and patients overdose. This gives us an idea of the benefit and the importance of pharmaceutical validation in chemotherapy treatment optimisation and patient safety.

Conflict of Interest No conflict of interest