In what clinical scenarios do you utilize opioids in patients with restless leg syndrome?

I would say in refractory RLS. I.e., the patient has failed all the options below:

1. Iron supplementation if ferritin <50,
2. Gabapentin/pregabalin,
3. Dopamine agonists, and
4. Non-pharmacological options (like the vibrating pad).

* I don't love carbidopa/levodopa for RLS. It very often causes augmentation.