Mounjaro® (tirzepatide)

Mounjaro® tirzepatide website image 2

In recent weeks, the PDL Professional Officers have received a number of queries regarding pharmacists’ obligations and liability when dispensing Mounjaro® (tirzepatide).

Tirzepatide is a long-acting dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. It is registered with the TGA and indicated for the treatment of adults with insufficiently controlled type 2 diabetes mellitus as an adjunct to diet and exercise, as monotherapy when metformin is not tolerated or contraindicated, or in addition to other medicinal products for the treatment of type 2 diabetes. While not approved in Australia for the use in weight loss, it seems many of the enquiries to PDL relate to this off-label indication.

The Professional Officers would like to remind pharmacists of their obligations to ensure all medications supplied are safe and appropriate for the individual patient. To ensure these obligations are met, it is recommended that the following information be considered.

Single dose vials

Medicines should be administered according to approved product information and manufacturer’s instructions. Use outside these instructions should only occur if there are well-documented resources supporting alternative administration methods.

Mounjaro is currently available in Australia as single dose vials in the following strengths:

  • 2.5mg/0.5mL
  • 5mg/0.5mL
  • 7.5mg/0.5mL
  • 10mg/0.5mL
  • 12.5mg/0.5mL
  • 15mg/0.5mL

The Professional Officers have received several reports from pharmacists that patients have been prescribed higher concentration vials and directed by prescribers to administer smaller weekly doses from the single use vial. This advice seems to be offered as a means to reduce the cost per dose for the patient. While that might be understandable, PDL is concerned for pharmacists if there is an adverse consequence for a patient and it is claimed this outcome was due to contamination from a vial being used for multiple doses.

The Professional Officers recommend discussing their concerns regarding multi-dose use from the single use vial with the prescriber. After speaking with the prescriber, the pharmacist should discuss their concerns with the patient, acknowledge the prescriber’s instructions, discuss the risks associated with multi-dose use and reiterate the manufacturer’s instructions that the vials are for single use only and any remaining medication in the vial should be disposed of as expired medicine.

The patient may still choose to use multiple doses from a single vial, however they should only do so with a very clear understanding and acknowledgement that they accept greater responsibility for any consequences if they use a medication in a manner that is outside the guidance in the approved product information. A pharmacist may choose to supply the medicine, with advice to the patient that they will be documenting the discussion and the patient’s acknowledgement and acceptance of risk and their responsibility.


As for all medications, patients supplied with Mounjaro should be adequately counselled on indication, directions, interactions and potential adverse effects.

The Professional Officers are concerned that patient administration errors may occur when a prescriber has ordered a higher concentration vial and advised the patient to use a lower dose. If the prescriber’s directions are not specific and the pharmacist doesn’t ascertain the intended dose, there is a prospect the patient may administer the full dose from the vial and experience side effects. Any non-specific directions should always be clarified by the pharmacist.

Patients using Mounjaro for weight loss should also be counselled on off-label prescribing. Off-label prescribing and supply is legal in Australia. To avoid confusion, it is essential that pharmacists advise patients that their medication has been prescribed for an indication, for which it is not currently approved in Australia, known as ‘off-label’, and explain what this means and how it may impact them. The pharmacist should ensure the patient understands the potential risks and benefits of use for a non-approved indication. The patient should have the opportunity to ask questions, be able to make informed consent, and understand that the discussion and their decision will be documented by the pharmacist.

Administration education

Pharmacists are required to ensure that patients are capable and competent to administer any supplied medications. Mounjaro is intended to be administered by subcutaneous injection. Pharmacists must consider whether educating a patient on administering medicine by subcutaneous injection is within their scope of practice. If not, the patient should be referred to the prescriber or another appropriate health care practitioner.

Scope of practice is determined by each individual pharmacist taking into consideration legislation, training, experience and demonstrated competency. It is recommended that pharmacists who determine that it is within their scope to provide education on subcutaneous injection should only do so as per the manufacturer’s instructions.

Administration by pharmacist

The Professional Officers are aware that some patients have requested pharmacists administer Mounjaro to the patient in the pharmacy. This may be an initial dose to demonstrate use or may be ongoing administration according to patient needs. Either way, Mounjaro should be administered as per the manufacturer’s instructions. Patients should be advised before administration that the medicine will be injected as a single dose from the vial with the recommendation any remainder is disposed of as an expired medicine.


The Professional Officers strongly advise pharmacists to document all communication with prescribers and any counselling or education provided to the patient including discussion of off-label use and informed consent.


Pharmacists may also consider contacting the manufacturer Eli Lilly Australia for further guidance on the use of Mounjaro.

For immediate advice and incident support, call PDL on 1300 854 838 to speak with one of our Professional Officers. We are here to support our pharmacist members 24/7.