If one is not chasing nodding type high then morphine in pill form is not the way to go. But if you're into IV usage and have pure pharma morphine hcl vials then that changes the whole conversation. Oxycodone is one of the most orally abusable opioids there is. I've never tried oxymorphone (metabolite of oxycodone) so I can not judge that one but oxycodone effected me just perfectly. I used it for pain a while back when my pain wasn't treated and combination of analgesia without the heavy sedation that morphine brings made oxycodone perfect for me.
But since OP is not taking it (presumably) to get high (although wanting to have more energy and motivation is not something that I would consider an issue) but for debilitating pain we are talking about different things. Morphine sulphate is not enjoyable as oxycodone when taken orally and it even made me anxious with a headache when I started taking it. I was getting it "on the streets" (same as oxycodone) and only thing that made me buy another batch of MS pills was the fact that it was really good for pain. I couldn't get the script from my idiot doctor but the pain was insufferable so I had little choice if I wanted to stay employed. Since I needed the money for paying the bills I suffered through the side effects for 2-3 weeks but then it became truly great analgesic medication. In my case tolerance to sedation came much faster than tolerance for analgesic effects. Best combination I found was slow release morphine plus imidiate release oxycodone with a ratio 1/1 miligram wise - 80mg of SR morphine divided in two doses and 4 20mg doses of "home made IR oxycodone"...in actuality 80mg Oxycontin devided by 4 and crushed). That way I had pain covered but wasnt as sedated compared to morphine only. Thankfully after long period and many types of examinations I was finally put on morphine and it does the job pretty well.
@Benny75 Sorry that I spent so many words about my experiences but I wrote it so you can relate...Back to you.
Although opioid charts are pretty established have in mind that some types of pain respond better to morphine than oxycodone. This goes for all opioids. And since our bodies differ in many subtle but in some cases profound ways - the response such as how much of certain medication is absorbed and how it affects us differ. Plus you are transitioning to another opioid and tolerance you developed while taking oxycodone is not 1:1 when crossing to morphine. You have said it yourself that it is a different type of feeling and precisely more sedative nature of morphine has to be taken into consideration if you don't want to have pronounced side effects. The overall dosage is not confusing to me but taking IR morphine every 12 hours is. This whole post is personal experience and speculation based on very restricted knowledge that I obtained from personal research, not medical advice or professional opinion, but I think that your doctor is trying to keep your tolerance as low as possible but will adjust your medications based on the response. I can see IR being prescribed every 6 hours as next adjustment and then that would make your overall morphine dose same/similar to previous dose of oxycodone, based on opioid conversion charts and calculators.
Just be honest with your doctor and tell all good and bad effects you get from morphine. Who knows maybe you could get SR morphine and IR oxycodone in the future. It is the best of both worlds in my experience.
I am sorry for the situation you've found yourself in and hope that you'll get the relief you need and deserve.
Take care!
