Tacrolimus: The Test Test not listed? Often referred to by brand name (see MedlinePlus Drug Information) Therapeutic Drug Monitoring, Cyclosporine, BUN, Creatinine, Electrolytes, Potassium, Magnesium, Comprehensive Metabolic Panel, Glucose Tacrolimus is ordered frequently at the start of therapy, often daily when trying to establish a dosing regimen. Once dosages have been established and shown to be well tolerated, then the frequency of tacrolimus testing may be decreased. The test is performed when dosages are changed and whenever patients have symptoms that suggest side effects, toxicity, or organ rejection. Monitoring at intervals is necessary as long as the patient is taking tacrolimus.