Prescription drugs to treat hay fever containing the same content as their nonprescription counterparts should be excluded from public medical insurance coverage, the National Federation of Health Insurance Societies said in a proposal released Friday.

The federation, commonly known as Kenporen, drew up the proposal as a measure to improve the financial health of the public medical insurance system, which is struggling with the negative effects of a graying population.

The federation of health insurance unions for corporate employees estimates that the measure would help cut the country’s medical costs by as much as about ¥59.7 billion a year.

But hay fever patients, who pay only 10 to 30 percent of the costs of such drugs thanks to the coverage, would need to fund the full cost from their own pockets.

The release of cedar pollen, which affects much of the nation between February and May each year, triggers an allergic reaction in about 1 in 4 of Japan’s population of about 126 million. Cedar pollen allergies weren’t common in Japan until the mid-1960s, when the first cases were reported near a cedar forest in Nikko, Tochigi Prefecture.

In the 1950s and 1960s it was national policy to plant forests of Japanese cedar and cypress trees, as they grew rapidly and produced hardwood for housing. With trade liberalization, however, cheaper hardwoods from Southeast Asia flooded in and the cedar and cypress forests were left to grow unchecked, emitting masses of pollen each spring.

The proposal to cut public medical insurance coverage of hay fever drugs was presented at a meeting of the Central Social Insurance Medical Council, which advises the health minister, ahead of medical service fee revisions for fiscal 2020.

Kenporen analyzed medical consultations received by those insured by its member unions, part of the country’s universal medical insurance system, between October 2016 and September 2018.

Through the analysis, it obtained an estimate that the removal of one hay fever drug alone from the coverage would lower annual drug costs paid under the insurance system by ¥3.7 billion. The proposal said the exclusion of any hay fever drugs should start with limited scope at first.

Premiums paid by insured company workers are expected to rise further, as the financial health of many unions is projected to worsen due to the introduction of very high-priced medicines costing tens of millions of yen.

Corporate health unions also need to raise contributions to fund health care for the elderly.

Kenporen estimates the total medical costs for prescription drugs that can be replaced by nonprescription ones at ¥212.6 billion.

In the past, it also proposed excluding from insurance coverage packing sheets and moisturizers that are prescribed by medical institutions but can be replaced by their nonprescription counterparts.

“Certain exclusions are necessary” to maintain the public medical insurance system, a Kenporen official said.

The latest proposal also called for wider use of inexpensive generic drugs for treating lifestyle diseases, estimating that costs of medicine could be reduced by ¥314.1 billion a year by doing so.