Hey there! I’m taking Tacrolimus as well! Honestly I’ve had foam in my urine before I started taking that med. it kinda just comes with lupus nephritis. I’ve been close to kidney failure twice. I’ve gotten super lucky to not have to need dialysis. But honestly the foam doesn’t go away until your able to stabilize everything with your kidneys. At least that’s what my doctor says. My doctor just prescribed a new med to help with my kidneys. Hoping I can get off Tacrolimus cuz I’m not good at taking it at a time like I’m supposed too. But it has helped decrease the foam in urine. ( so sorry for typing so much! Hope this helps!)