Compliance with the hospital protocol of therapeutic drug monitoring for high-dose MTX in National Cancer Hospital

Abstract

Methotrexate is an important anti-cancer drug, which
is listed in the World Health Organization’s essential
drugs. The therapies using high dose methotrexate
(HDMTX) have been commonly used at the National
Cancer Hospital (K Hospital) in Vietnam. In order to
ensure the effectiveness and safety of this important
drug, a therapeutic drug monitoring (TDM) protocol
for HDMTX has been formulated by the Pharmacy
department at K Hospital and was then approved by the
Hospital Director in November 2018.
The objective of this study was to examine the level of
compliance with this TDM protocol in clinical practice
at the hospital. The study was conducted from July
2019 to February 2020. A total of 174 cycles of HDMTX,
including the ones of the treatment for non-hodgkin
lymphoma (66.7%), osteosarcoma (30.4%), and acute
lymphoblastic leukemia (2.9%), were included in the
study. The administrations of 137 cycles were 4-hour
transfusion and the remaining cycles’ were 24-hour
transfusion. The results showed that there was no cycle
fully complied with the protocol. When considering steps
in the protocol individually, the compliance percentages
were 47.1% for pre-transfusion evaluation, 14.9%
for the rehydration and urine alkalization procedure,
58.6% for methotrexate quantification, and 19.0% for
rescue procedure with leucovorin. The research results
indicated that the compliance proportions with the TDM
protocol at K Hospital were low. More studies should
be conducted to find out the reasons and difficulties in
the adherence to the protocol, or the consequences on
patients’ outcomes of the non-compliance to protocol
practice so that its adherence can be improved.