May reduce the effect of probiotics in the body w/ antibiotic medicines (take probiotics at least 2 hr before or after antibiotics). May increase chances of getting sick w/ bacteria & yeast w/ drugs that weaken the immune system (eg, medicines used to prevent transplant rejection eg, azathioprine, basiliximab, ciclosporin, daclizumab, muromonab-CD-3, mycophenolate, tacrolimus, sirolimus & prednisone).