A rise in the number of diabetes treatment regimens prescribed outside of PBS restriction criteria has led to fresh calls for the rules to be simplified.

Released this week, the PBACs Drug Utilisation Sub Committee (DUSC) review into the use of diabetes drugs found that at least 51,000 patients had regimens outside the PBS restrictions in July 2016.

This related mostly to an increase in the use of SGLT2 inhibitors, DPP-4 inhibitors or exenatide as monotherapy, as well as a growing number of patients on regimens that included both SGLT2 inhibitors and a DPP-4 inhibitors combined with either metformin or metformin and a sulfonylurea, all of which is not allowed under current PBS restrictions.

The committee conceded that some of that use may be clinically reasonable, for example in dialysis patients with diabetes who are unable to use metformin or sulfonylurea.

The review, which took place in February this year, followed a spike in the number of new diabetes medicines and extensions to PBS listings that have taken place since the last DUSC review in February 2013.

In its review the committee acknowledged that the restrictions are ‘complex’ and difficult for doctors to navigate. It has recommended that the PBAC simplify the criteria.

That admission is a win for some doctors and industry groups whose calls to simplify the criteria during stakeholder meetings for the 2013 review went unheard.

While the PBAC has now agreed that simplification of the restrictions ‘warrants further investigation’ it has said there will be “challenges in harmonising the restrictions into a general statement, including the lack of consistency in subsidised indications within classes of diabetes medicines.”

Other highlights from the review:

• The regimen group with the highest number of patients was metformin + DPP-4 inhibitors + insulin, which was PBS subsidised from 1 November 2016
• The next most common group was metformin +DPP-4 inhibitors + SGL-2 inhibitors.
• The top three regimens in 2016 were metformin monotherapy, insulin monotherapy and metformin + sulfonylurea, respectively.
• The number of patients using metformin monotherapy has gradually increased, insulin monotherapy remains constant and the number of people using metformin + sulfonylurea has declined.

Current PBS restrictions

Metformin, sulfonylureas, acarbose and most insulins and analogues have unrestricted PBS listings.

Insulin detemir has a restricted benefit listing for type 1 diabetes. Bovine insulins are Authority Required for diabetes mellitus where the patient is intolerant to human insulin.

The DPP-4 inhibitors, SGLT2 inhibitors, GLP-1 analogues and pioglitazone are Authority Required.

(STREAMLINED) listings for patients meeting certain criteria and for use in combination with specified medicines.

Rosiglitazone has an Authority Required (telephone) listing for patients meeting certain criteria and in combination with other specified medicines because of safety concerns.

Initiation on any of these medicines requires patients to have, or have had, a HbA1c measurement greater than 7% despite treatment with specified medicines; OR if HbA1c measurement is clinically inappropriate, blood glucose levels above 10 mmol per L in more than 20% of tests over a 2 week period despite treatment with specified medicines.

Full details of the PBS eligibility criteria are available from www.pbs.gov.au