Tecfidera Disease Interactions

Serious cases of herpes zoster have occurred in patients treated with dimethyl fumarate; patients should be monitored for signs/symptoms of herpes zoster while on dimethyl fumarate. Other serious opportunistic infections have occurred with dimethyl fumarate, including cases of serious viral, fungal, and bacterial infections. Patients with signs/symptoms consistent with any of these infections should undergo prompt diagnostic evaluation and receive appropriate treatment. Withholding dimethyl fumarate treatment in patients with herpes zoster or other serious infections until the infection has resolved should be considered.

Dimethyl fumarate has not been studied in patients with liver dysfunction; although no dosage adjustment is needed, caution is recommended when using dimethyl fumarate in these patients. Clinically significant cases of liver injury have been reported in patients treated with dimethyl fumarate in the postmarketing setting. Signs/symptoms of liver injury, including elevation of serum aminotransferases to greater than 5-fold the upper limit of normal (ULN) and elevation of total bilirubin to greater than 2-fold ULN have been observed; these abnormalities resolved upon treatment discontinuation. Elevations of hepatic transaminases (most no greater than 3 times ULN) were observed during controlled trials. Serum aminotransferase, alkaline phosphatase, and total bilirubin levels should be obtained prior to and during treatment with dimethyl fumarate, as clinically indicated. Therapy should be discontinued if clinically significant liver injury induced by dimethyl fumarate is suspected.

The use of dimethyl fumarate may decrease lymphocyte counts. Dimethyl fumarate has not been studied in patients with preexisting low lymphocyte counts; caution is advised in these patients. CBC (including lymphocyte count) should be obtained before initiating treatment with dimethyl fumarate, 6 months after starting treatment, every 6 to 12 months thereafter, and as clinically indicated. Interruption of therapy in patients with lymphocyte counts less than 0.5 x 10(9) cells/L persisting for more than 6 months and withholding treatment from patients with serious infections until resolution should be considered. Caution is recommended and decisions about whether or not to restart dimethyl fumarate should be individualized based on clinical circumstances.

Progressive multifocal leukoencephalopathy (PML) has occurred in patients with multiple sclerosis (MS) treated with dimethyl fumarate; PML is an opportunistic viral infection of the brain caused by the John Cunningham virus (JC virus) that generally only occurs in immunocompromised patients and usually leads to death or severe disability. Caution and monitoring are advised in patients with MS. Dimethyl fumarate should be withheld at the first sign/symptom suggestive of PML and an appropriate diagnostic evaluation should be performed.

Dimethyl fumarate has not been studied in patients with renal dysfunction; although no dosage adjustment is needed, caution is recommended when using dimethyl fumarate in these patients.