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.