Here in Australia, Tirzepatide (Mounjaro) is supplied as a
single-use vial that is used once a week, ideally on the same
day each week.
When you first start using Mounjaro, the starting dose is
2.5mg once a week for 4 weeks. After 4 weeks your dose
will be increased to 5mg once a week.
Your doctor may choose to increase your dose by 2.5mg every
4 weeks to achieve a dose of 7.5mg, 10mg, 12.5mg or 15mg
once a week if needed.
The maximum dose is 15mg once weekly.
Also, in Australia, practise nurses are not medically qualified in
order to initially write prescriptions and/or adjust your current
medications
without the express approval of the prescribing doctor.
I've noticed in the past here that people talk about "practise nurses"
prescribing drugs and/or adjusting dosages in the UK, or in your
case "point blank refusing" something. I can understand your concern
with this particular scenario, and I'm confused as to why your treating
doctor isn't the person monitoring your medication.