I guess it depends on your coverage. My plan, Kaiser, has an option for doctors to get coverage for non formulary drugs when necessary. Doctors just agree to use the formulary meds first before going off the list. When ordering there is some sort of exception code they use to get coverage. It still is expensive, but at least there is coverage and once I reach my out-of-pocket maximum, I pay $0 co-pay. My out-of-pocket maximum is high ($6800, with a $4800 deductible), so I have to plan for that expense early in the year. Unfortunately, I max out by the end of February every year.
I'm retired and do not qualify for Medicare yet, so I worry about the ACA shutting down.