DISCUSSION
Distress financing pays for the majority of hospitalizations for
paediatric cancer care patients in both rural (over 60%) and urban
(40%) areas [9]. Given the enormous economic burden posed by
anticancer drug treatment, it is unacceptable to bear the incremental
cost of drug wastage. In this study, we audited parenteral chemotherapy
drug wastage and estimated the economic loss incurred due to it at our
paediatric oncology day care unit.
Our study evaluated 100 patients who received 140 parenteral drug
administrations of 21 different chemotherapy drugs. We found that
19.61% of the parenteral chemotherapy drug was wasted, which is similar
to the study conducted by Gopi Shankar et al. [6]. In their study,
they prospectively quantified chemotherapy drug wastage in adult
patients and observed significant drug wastage of 19.72% in 3 months
and 17.14% in 1 year for 313 patients attending the oncology unit.
Several other studies conducted in oncology units have reported
significant, but highly variable, drug wastage ranging from 1% to
33.8% [10],[11], [12], [13], [14]. However, most of
the reported studies were conducted on adult cancer patients, and there
is sparse data on paediatric patients.
In our study, we observed that the amount of wasted drugs, i.e.,
19.61%, resulted in an economic loss of 31929.95 INR (385.19 USD),
which accounted for 28.98% of the total drug cost. Similarly, in a
study conducted by Gopi Shankar et al. [6], the cost due to drug
wastage was found to be 17.14% of the total expenditure on drugs over
one year. In a drug waste study by D’Souza et al. [4], 6.1% of the
reconstituted drugs were wasted, and the cost analysis amounted to
11.1% of the total drug cost. The lesser amount of wastage observed in
D’Souza’s study suggests that some strategies for waste reduction may be
already in place in their setup, although this was not clarified in the
study results.
We found that doxorubicin (37.4%, 95% CI: 16.67-58.12) had the highest
amount of drug wastage followed by cytarabine (35%, 95% CI: 0-62.5)
and L-asparaginase (27.34%, 95% CI: 20.27-33.52) which were prescribed
for ALL. The economic loss due to this wastage was 3301.36 INR (39.83
USD) for doxorubicin, 681 INR (8.22 USD) for cytarabine, and 12054 INR
(145.41 USD) for L asparaginase. So the baseline cost of a single unit
results in more financial loss for even smaller wastage as seen with L
asparaginase. Other drugs frequently used in the treatment of ALL like
intrathecal methotrexate administration (n=26) and vincristine (n=29)
administrations also contributed to wastage of 23.08% and 18.63% and
financial loss of 289.27 INR (3.49 USD) and 328 INR (3.96 USD)
respectively. The individual drug wastage seen in our study cannot be
compared to other studies as the majority of the reported studies were
conducted in adult cancer patients with different drug use spectrums.
In our study, the drug wastage and financial loss encountered for the
single administration of irinotecan prescribed for primitive
neuroectodermal tumours and fludarabine prescribed for acute myeloid
leukaemia were 85% and 68%, respectively. The financial loss for
irinotecan was 3305 INR (39.87 USD), and for fludarabine, it was 6204
INR (74.84 USD). However, there was no drug wastage observed in
bortezomib, carboplatin, dactinomycin, or ifosfamide administrations
since the dose administered matched the amount available in the vial
exactly.
Various mitigation approaches can significantly reduce chemotherapy drug
wastage. For instance, a study by Fasola et al found that using
multidose vials with stability for up to 24 hours, scheduling
chemotherapy sessions by grouping patients as per pathology or drug,
rounding by 5%, and using appropriate vial size as per the estimated
daily usage of each drug reduced drug waste expenditure by 45%
[15]. These cost and waste containment strategies have been proven
effective and can be implemented to optimize resource utilization in
cancer care. For commonly used drugs such as l-asparaginase, intrathecal
methotrexate, and vincristine in ALL treatment, waste mitigation
strategies such as pathology-wise batching or drug-wise batching can be
considered. However, the cost-effectiveness of these approaches needs to
be evaluated in further studies before implementation.
In vial sharing, the remainder from each vial is retained and can be
used for the next patient while dose rounding is a method that either
increases or decreases a prescribed dose to the nearest whole vial
strength available [16]. However, our study found that vial sharing
and rounding of dose were used in only 19.29% (n= 27) of drug
administrations. Rounding was done in 15.71% and sharing was done in
3.57% of drug administrations. To ensure safety and effectiveness, each
institution should establish its criteria for automatic dose rounding,
allowable percentage, and processes for operationalizing and documenting
any modifications to the original prescribed dose. Additionally,
exceptions to the dose-rounding policy should be determined a priori
[8]
It is worth noting that all drug formulations available at your pharmacy
were single-dose vials as per the manufacturer’s label because they lack
preservatives. Therefore, each shared vial must be appropriately logged,
unpackaged, and stored, and its sterility must be ensured for later use.
As two or more patients are treated from a single vial, the chances of
microbial contamination cannot be negated, and proper precautions must
be taken to minimize the risk of infections [16]. Vial-sharing
challenges can be eased through drug vial optimization (DVO), which
extends drug sterility and stability up to 7 days using closed-system
drug transfer devices (CSTDs). These devices move drugs between
containers, like vials to syringes, without contamination or
environmental release. In an international survey by Gilbar et al., only
India and Japan among 12 countries denied using DVO for anticancer
injections [8].
For doxorubicin, cytarabine, methotrexate (intrathecal), and
vincristine, the prescribed doses did not align with the available vial
sizes. Regarding l-asparaginase (n=31), only 5 drug administration’s
perfectly matched the vial sizes. Bach et al. suggested that
policymakers should urge manufacturers to offer drug packaging in
various sizes to minimize wastage. Additionally, further research into
disease-specific body surface areas and weights could provide insights
into ideal vial size options for waste reduction. Establishing
guidelines, such as limiting wastage to a specified percentage of the
vial size based on average patient body surface area or weight derived
from disease-specific population data, could incentivize pharmaceutical
companies to package drugs in sizes that reduce excessive wastage
[12].
The limitations of our study are that monoclonal antibodies and small
molecules were not routinely used at our institute which is unlike the
private sector where they are now widely used. Also, to devise a
comprehensive strategy to minimize the drug wastage it would be
appropriate to estimate wastage encountered with specific cancer like
ALL in our setup.