High cost of cancer medicines isn’t the sole reason why they are so expensive for insurers and patients. A study has found that wasted medicine also adds to the bill because the distribution of infused cancer drugs is done in vials in the US that generally include more medicine as compared to what most patients require.

In most cases, insurance companies or patients end up paying for surplus medicine, which is generally thrown out. The cost of wasted cancer medicine has been calculated in billions of dollars.

New York’s Memorial Sloan Kettering Cancer Center researchers have estimated that in the US wasted cancer medicine will add up to around $3 billion in excess costs this year.

The results have come as the federal government and most of the health care system is looking forward to cut waste and overall medical spending, accounting for nearly one-sixth of the US gross domestic product (GDP).

It is tough to rein in that spending, somewhere because there are a number of competing interests, a number of which get financial benefit from waste and pricing systems that are foggy at best whereas cancer medicines belong to the highest-priced, fastest-growing drug categories.

In an interview, the study’s lead author, Dr. Peter B. Bach, said that hopefully their regulators are going to take this as an issue worth addressing. On Tuesday, the study appeared in the British Medical Journal.

The study has mentioned in detail how drug makers, hospitals and cancer doctors earn money from unused cancer medicine. It targeted the top 20 drugs for multiple cancer types placed in single-dose vials and for which the dose relies on the weight of patient, finding that 1% to 33% of the 20 cancer drugs, on average, stays in vials after every drop is administered.