Morphine Sulfate is available in short acting preparations, known as Immediate Release (MSIR) formulations. It is effective rapidly, especially when taken in the liquid formulation. It is often referred to as "rescue" or "breakthrough" doses when used with long-acting preparations
Advice & Tips:
No problem with this medication, it worked great on breakthrough pain. My only concern was that I would develop a high tolerance for it and if I was ever seriously injured or became chronically ill, then it would not be affective. I also know now that I was not educated properly by my PCP at the time. I was given the false pretense that this medication would eliminate my pain 100%. After I struggled for over a year with managing my pain (and not taking medication properly because of being uneducated) I did the research on my conditions and pain medications and learned that you are always going to feel up to 30% of pain and the goal should be to lower the pain level as much as possible with medications and alternative methods like a heating pad for example.