Diabetes expert defends prescribing patterns

Drug use report highlights how many more treatment options diabetes patients have now compared with 20 years ago

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Prescribers of diabetes drugs have been defended, after a government report highlighted a number of “concerning” trends in prescribing habits over the last four years.

The subcommittee monitoring drug usage for the Pharmaceutical Benefits Advisory Committee recently released their February meeting report showing increasing rates of monotherapy with flozins, gliptins and exenatide, as well as other combinations not approved under the PBS.

Moreover, the number of patients taking four or more therapies raised questions about quality use of medicines, the committee warned.

But instead of being met with alarm by the diabetes community, the results have been welcomed.

“In terms of management of the disease it’s fantastic, terrific, amazing,” said endocrinologist Professor Andrikopoulos, chief executive of the Australian Diabetes Society.

“Now we’ve got all these other drug classes we can utilise to manage their blood sugar levels and to prevent complications,” he said.

The committee meets regularly to evaluate the use of medicines, and undertook this analysis in light of the number of new classes of drugs being added to the PBS, and other listings being expanded.

A growing area of concern according to the authors of the report was the use of flozin, gliptin and exenatide monotherapy, which were being used for 3000, 8000 and 1200 patients, respectively.

The use of flozin, gliptin and/or GLP-1 analogues in combination with each other also accounted for more than 27,000 regimens, despite not being approved on the PBS.

But instead of indicating people were being treated inappropriately, these figures only really reflected the proportion of people who were being treated outside of the PBS criteria, Professor Andrikopoulos said.

It might make it more expensive and potentially unaffordable for some people long-term to not be covered by the PBS, but he said the more important thing was that the report highlighted how many more treatment options patients had available to them now compared with 20 years ago, he said.

“If it’s appropriate for an individual to be treated with an SGLT2 inhibitor as first line therapy then it is what it is,” he said. “The Australian Diabetes Society treatment algorithm suggests that usual therapy is metformin, followed by sulfonylurea. If metformin is not tolerated, then the first line can be sulfonylurea.”

Nevertheless, it was positive that the report still found metformin was a first-line therapy, he said.

Professor Andrikopoulos also hit back at the idea that rapidly growing rates of patients on more than four medications indicated potentially poor management and a risk of polypharmacy.

“I think it’s matter of the healthcare professional trying to manage their patient’s diabetes,” he said. “Without knowing the disease duration and pathology of the individual it’s hard to say it’s concerning or not concerning.”

“If a patient has not been treated for many, many years and their glucose is not under control, then maybe many drugs are needed to get them at a HbA1c level that is controlled.”

The report found that by mid-2016, 3.85% of the population was estimated to be taking diabetes drugs, and that half of these were taking only one medication.

Metformin monotherapy was still the most common regimen, followed by insulin monotherapy, gliptin and metformin, metformin and sulfonylurea and then insulin and metformin.