Background and importance One of the most frequent complications of antineoplastic treatment is the drugs’ toxicity, which can lead to temporary or definitive treatment interruptions, dose reduction, prescription of support drugs and even visits to the doctor and hospital admissions. Pharmaceutical validation aims to optimise chemotherapy treatment in order to obtain the best results for patients’ health.

Aim and objectives To describe the pharmaceutical interventions made in the oncohaematology area during the validation of intravenous cytostatic preparations that led to a change in prescribing.

Material and methods Observational, descriptive and retrospective study in which the pharmaceutical interventions carried out in intravenous chemotherapy prescriptions in oncohaematological day hospital recorded between November 2020 to September 2021, were analysed. The programme used for prescribing and recording was OncoFarm.

Interventions were classified into 9 groups: (1) upper/lower dose <10%; (2) upper/lower dose >10%; (3) inappropriate cycle frequency; (4) relevant interaction or adverse effect; (5) dose adjustment (renal and hepatic impairment, toxicity); (6) incorrect protocol; (7) missing drug; (8) excess drug; (9) others.

Results During the study period, 1554 outpatients (67% oncological and 33% haematological) received chemotherapy treatment. 124 chemotherapy prescriptions of 101 patients were changed due to medication errors detected during pharmaceutical validation. According to the classification: in 23% of prescriptions (29/124) a reduction of the dose was made, this dose difference being greater than 10% in 90% of cases, avoiding mostly a patient overdose; 10% (13/124) changes were due to inadequate chemotherapy cycle frequency; 27% (34/124) changes were temporary suspension of treatment, change of dose and/or administration of supportive medication due to drug toxicity or dose adjustment due to renal or hepatic impairment; in 12% (15/124) changes were due to an inadequate frequency of chemotherapy cycle; in 14% (17/124) there was a lack or surplus of medication and in the remaining 14% (17/124) the prescription changes were for other reasons.

Conclusion and relevance Despite the number of pharmaceutical interventions not representing a large volume in the total number of patients treated, they led to a probable reduction in adverse drug events, toxicities and patients’ overdose. This gives us an idea of the benefit of having a pharmacist as part of the multidisciplinary team in oncohaematology and the importance of pharmaceutical validation in chemotherapy treatment optimisation and patient safety.

Conflict of interest No conflict of interest