8 years is a very clinically significant period of time to be on any medication without interruption. As you are probably acutely aware, Buprenorphine (Suboxone; Subutex; Buprenex) is a long(er)-acting analgesic than Morphine by quite a large margin. It's going to vary from person to person and I admittedly am not as familiar as I should be regarding Buprenorphine as an analgesic. I am very familiar with its usage as a maintenance medication. Anyway,you will most likely be taking 3 doses of Morphine for every 1 dose of Buprenorphine in terms of duration of effect and not dosage.
I know some of this information is elementary, but it's important. Buprenorphine is a powerful Opioid agonist, but it is also a partial-agonist as well. This makes its biochemistry much more difficult to discuss in absolute terms. At any rate, I am trying my best to adapt what I know about Bupe to your situation. I understand that much like Methadone, another powerful and long-acting Opioid, Buprenorphine has an acute withdrawal syndrome that can be as long as 2-3 weeks with lingering effects for up to 3 months before a true return to normalcy begins. There are those who are still very troubled by symptoms of cessation even years after discontinuation although this is not the norm.
I would expect that you will begin to see a very serious change in how the Morphine effects you as you approach the one month mark of abstinence from the Buprenorphine. Also, don't be freaked out by what I've said. The numbers and severity are for people who are on higher doses and not actually switching to another Opioid. I believe you're dealing with the aforementioned "lingering" effects of the Buprenorphine. It's also my belief that 60mg of Morphine will treat you well once you do reach this point.
