no national health program, it's the health insurance plans run by the provinces for people on welfare/disability (might not be every province, but i know ontario doesn't cover oxy neo). even though we have free health care in canada, we still pay for medications (or have health insurance plans through employers/schools that pay for them).
We've got something similar called Medicaid. But I'm not sure if it covers prescriptions, whether you have to make co-payments or whatever. It's for low income people and pays for doctor visits and such. Actual Medicare is mainly for retirees and people on Social Security Disability or SSI, after they've been on it 2 years. But, depending on the state, it can be very hard to get on SSD or SSI. You basically have to be declared to be completely unable to perform any work at all, and the key word is "declared", because even if you have a ton of medical evidence an administrative law judge can still rule against you. So a lot of people just fall through the cracks. There are charities and free clinics, mostly run by churches that help some of these people out, but often they'll only cover one script, and no refills.
I was just explaining the "why switching to OPs would cause withdrawals" question. Don't need jump down my throat.
Please explain the jumping down the throat part, because I don't see it, and I certainly didn't intend it.