Best Practice is advising GPs not to use its program to generate scripts for long-acting insulin due to a glitch linked to the new active ingredient prescribing rules.

The advice was issued after a doctor noted that prescriptions for Novomix, a mix of long-acting and rapid-acting insulin, were being converted to a different formulation.

As a precaution, the company has urged 25,000 doctors using its software to hand-write all scripts for long-acting insulin until the glitch is sorted out next week.

The problem has likely been in place since Best Practice updated its software to accommodate the new rules demanding that the active ingredients of prescribed PBS medications are printed first on any script generated using a computer.