I’m putting my money on the CellCept. You said that’s a new one in your world, and it is well known to wreak serious havoc in the GI-system… Which is why a lot of patients can’t use it despite being a smaller step before Cytoxan (even worse effects) & Rituxan (expensive/off-label.)
Personally, I was on CellCept for all of two weeks, just till finishing my taper up to the intended dose, when I ended up in the emergency room for sudden, severe nausea and vomiting when I woke up one morning. I woke up at my usual time after a good 8hr sleep (better than usual for sure!) and as soon as I was conscious I just froze there in bed, realizing if I even moved wrong I was going to throw up. I tried lying on my side, but all I could handle was flat on my back, and I had to lie still and breathe deeply for about 15 minutes before I could make it 15 feet to start vomiting more violently and painfully than I ever have. And I had some bad “flus” as a kid… I continued like that for over a hour before calling a neighbor to take me in (sets of 3-4 heaves every 10-15 minutes of calm breathing in child’s pose next to the toilet) and somehow managed to suppress it for the 10-15 min ride in her car. At the ER I was back at it again, a little less often and dramatic but still painful. I also had severe widespread body pain and a horrible headache, but I don’t even drink alcohol and had stopped 6mo prior when I started plaquenil for my initial dx. I’m SO grateful my 50-yr-old neighbor came in with me, otherwise they might have assumed I was a bad hangover case (or whatever negative label the ER likes to apply to someone who comes in alone, as if being single and mostly alone handling your illness were a sign of being a failure in life… I have a different ER nightmare story like this.) Once I finally got a bed, they had me on IV anti-emetics (anti nausea Zofran, commonly used for chemo patients, worked like a miracle!) and morphine. Plus fluids, which I asked for an extra bag of since it was really tough to handle the water they were asking me to drink. After my labs came back, my potassium was low and out of range, which could explain my body aches. But then I had to drink and keep down this awful syrupy-salty concentrated potassium supplement! I normally avoid narcotics like the plague, but in this case I was more than happy they were ordered! Everything got calmed down pretty quickly over the next few hours after that and they discharged me with a script for oral Zofran and potassium tablets… And since I had relieved my neighbor of her generous, caring post of giving me the paper bucket and holding my hair while advocating for me till the meds started working, I actually took a cab to the pharmacy and home. Not just that I’m single, also no family in town, and it all happened too fast to have any reasonable search for other friends to help. Plus, most people who know me have no idea how quickly things can get serious, rather than just being “too tired to go out tonight.” (Sound familiar everyone?)
I wish you much better with this, since CellCept is a moderate “steroid sparing” therapy when Plaquenil isn’t enough, but the individual side effects we each have are what determines which drugs we can use. After trying CellCept, I went right to Rituxan, which has worked wonders with almost zero side effects (flu-like/flare-like symptoms for about 12-24hrs after infusions, 2 every 6 months.) I don’t recommend bringing up my whole dramatic experience with your rheumy, who may think your concerns are prone to suggestion by others, but DEFinitely tell him/her about the symptoms you are having, the timeline of when they happened, if they’re building over time, and if/when they’re really bothering you, alternatives. Act early, or at least track it and have a plan for if it goes south!
Take care, hope you feel better soon!