One point though—you mention that you're planning on taking the MS until the withdrawal symptoms from the oxycodone
subside. I can tell you this won't work the way you're thinking. Oxycodone
and morphine are interchangeable; as far as your body is concerned, they're the same thing in most ways.
In other words, you won't experience full withdrawal until you stop both opiates. Nevertheless, it may be easier on you to stop one and then, more gradually, stop the other.