Impact of pharmaceutical care on adherence to tyrosine kinase inhibitors in chronic myeloid leukaemia.

Abstract

Aims: Tyrosine kinase inhibitors (TKIs) have been successful in changing the course of chronic myeloid leukaemia (CML) due to their high efficacy. However, their effectiveness is conditioned by adherence to treatment. The aim of this study was to analyse the adherence of CML patients treated with TKIs and to evaluate the impact of pharmaceutical care on adherence in a prospective and interventional manner.

Methods: Multicentre, prospective study including CML patients on treatment with TKIs attending the outpatient units of the Pharmacy Services. Adherence was assessed using a combination of two methods: the Simplified Adherence Problems Scale and the treatment dispensing register (a patient with a percentage <90% being considered "non-adherent"); patients who demonstrated a non-adherence in either of these two methods were classified as "non-adherent patients". In individuals with inadequate adherence, PC was reinforced for 8 months by means of a specific programme.

Results: A total of 130 patients were included, 56.9% had optimal adherence to treatment. Pharmaceutical care in the oncohaematology-specific outpatient units of the Pharmacy Services improved adherence (from 67.1% to 90.9%; p < 0.001) while the generalist outpatient units kept it constant (from 70.2% to 72.4%; p = 0.509).

Conclusions: Adherence is one of the most relevant parameters in the effectiveness of chronic treatments. Approximately half of our CML patients showed inadequate adherence to TKIs. This is the first prospective study to determine that the pharmacist's actions in oncohaematology-specific outpatient units of the Pharmacy Services are capable of influencing adherence and improving it.