Low Dose Naltrexone
Start with 1.5mg mane, and can increase up to 4.5mg maximum. Efficacy maximum at 4-6 weeks.
In Auckland can get it from Compound Labs or Optimus. Cost is around $90 for three month supply. Some people are sensitive to the filler. Use sucrose or ginger filler instead of cellulose in that instance.
If the patient is able to manage then the cheaper and more adjustable option is you can prescribe the 50mg tablets, get them to dissolve in 100mL of water, making a concentration of 0.5mg/mL, and store in the fridge covered in aluminium foil. Use a syringe to measure doses (0.5mg, titrating up to max of 4.5mg). Warn them that it tastes foul. This can be a useful option when initiating in order to work out the dose needed.
External Links
https://www1.racgp.org.au/ajgp/2023/april/low-dose-naltrexone-in-the-treatment-of-fibromyalg
https://www.medicinesinformation.co.nz/2023/07/05/naltrexone-oral-liquid-formula/?pos=naltrexone