Coverage gap or "doughnut hole"

[jaysunb]

After nearly 6 years of SS and Medicare, I was informed that my many medications would now cost triple the regular amount for the next 3 months.
Now, I've always been aware of this phenomenon, but never thought it would affect me as my meds have not changed much over the years ---that is, until I started using the latest diabetes drug, Invokana. Initially they wouldn't pay at all, costing me $350 per month. After about 6 months and some request by my primary caregiver, they relented and gave it to me for $95.00. Great ! Then in January of this year, it suddenly cost only $45.00. OH JOY !

Well, I'm really not sure what happened but 9 months into the year I'm in a hole. ( I like doughnuts, and this aint it) I'm wondering if anyone else has seen a collapse in coverage this quickly or if there was some sort of increase that I missed ???