Hypersensitivity or anaphylactoid reactions. Assess renal function (eg, creatinine, BUN & urinalysis) prior to treatment initiation, after 3 & 6 mth of treatment, & every 6-12 mth thereafter; serum aminotransferases (eg, ALT & AST) & total bilirubin levels prior to treatment initiation & during treatment. Severe prolonged lymphopenia may occur. Patients w/ preexisting low lymphocyte counts. Perform CBC including lymphocytes prior to treatment & every 3 mth thereafter. Consider treatment interruption if lymphocyte counts <0.5 x 109
/L persists for >6 mth. Baseline MRI should be available before initiating treatment. Withhold use at the 1st sign or symptom of progressive multifocal leukoencephalopathy (PML) & perform appropriate diagnostic evaluation. Prior treatment w/ immunosuppressive or immunomodulating therapies. Patients w/ severe active GI disease. Consider suspending treatment if infections, herpes zoster occur. Monitor for signs & symptoms of herpes zoster. Gradually start Tecfidera treatment. Discontinue treatment if Fanconi syndrome occurs. Severe renal or hepatic impairment. Pregnancy & lactation. Childn & adolescents 10-18 yr.