Tysabri Disease Interactions

Serious and sometimes fatal infections have been reported in patients receiving immunosuppressive agents. Patients receiving immunosuppressants are at increased risk of developing bacterial, viral, fungal, and protozoal infections, and new or reactivated viral infections including opportunistic infections. Caution should be exercised when considering their use in patients with severe or chronic infections. It is recommended to interrupt therapy in patients who develop a new infection while undergoing treatment and to monitor these patients closely for any sign or symptom indicative of infection.

Immunosuppressive agents may increase the risk of progressive multifocal leukoencephalopathy (PML). Certain agents are contraindicated in patients who have or have had PML. Patients receiving chronic immunosuppressant or immunomodulatory therapy or who have systemic medical conditions resulting in significantly compromised immune system function should not be treated with these agents. Health care professionals should monitor patients for any new sign or symptom suggestive of PML. Therapy dosing should be withheld immediately and an appropriate diagnostic evaluation should be performed at the first sign or symptom suggestive of PML.

Postmarketing reports have associated the use of natalizumab with severe hepatic toxicity, including acute liver failure requiring transplant. Natalizumab should be discontinued in patients with jaundice or other evidence of significant liver injury and appropriate therapy should be instituted according to clinical guidelines.

Natalizumab increases the risk of developing encephalitis and meningitis caused by herpes simplex and varicella zoster viruses. It is recommended to monitor patients receiving natalizumab for signs and symptoms of meningitis and encephalitis. If herpes encephalitis or meningitis occurs, treatment should be discontinued, and appropriate treatment for herpes encephalitis/meningitis should be administered.