Drug Availability

HPS Pharmacies wish to advise that the Therapeutic Goods Administration (TGA) has given notice of a supply shortage for multiple brands of metformin modified-release 500mg tablets (also referred to as extended-release or XR tablets). These shortages are expected to continue until at least early June 2020.

To reduce the patient impact of this shortage, the TGA has issued a ‘Serious Shortage Medicine Substitution Notice’. This notice specifies the substitutions that pharmacists may make for patients presenting with a prescription for metformin modified-release 500mg tablets. Allowable substitutions are shown in the table below.

Dose of metformin XR 500mg Medicine that may be supplied
1,500mg daily Metformin XR 1,000mg +

Metformin immediate release 500mg

1,000mg daily Metformin XR 1,000mg
500mg daily Metformin immediate release 500mg

When an XR tablet is supplied, the timing of the dosing regimen should remain the same. Where a substitution results in supply of an XR and immediate-release tablet, the XR tablet should be administered at the usual time and the immediate-release tablet taken at a separate time.

Please note that this substitution notice is subject to the following conditions:

  • The patient/carer must consent to any substitutions;
  • The total quantity supplied must be equivalent to the number of days of therapy ordered on the original prescription;
  • Not to be used for regulation 49 (previously referred to as regulation 24) prescriptions; and
  • Substitution may not be appropriate in all cases, e.g. known hypersensitivity or previous severe adverse reaction to excipients, known intolerance to immediate-release metformin preparations; and
  • This notice applies from 13th May 2020 until 31st July 2020. However, it must be entered into state or territory law before being implemented.

It should also be noted that ‘Serious Shortage Medicine Substitution Notices’ are intended for use in community pharmacies rather than hospital pharmacy departments. Further information on these notices and their recognition in each state and territory can be found on the TGA website.

Retain this notice in a prominent position, including in other related business units until supplies return to normal. Report any problems identified with medicines, vaccines or medical devices to the TGA.

Should you require further information regarding this matter, please contact your pharmacist at HPS Pharmacies.

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