There are far better analogies than opiates though. There's no reason why a treatment that is working and is expected to continue to be effective indefinitely

There are far better analogies than opiates though. There's no reason why a treatment that is working and is expected to continue to be effective indefinitely should be withheld because a doctor's appointment didn't happen during the scheduled window one month, any more than my glasses should stop working because I didn't see my opthalmologist this year. Freedom to choose suboptimal outcomes is not a bad thing.