Drug Interaction Report

CONTRAINDICATED: The administration of live smallpox virus vaccine during fingolimod therapy may be associated with a risk of disseminated infection due to enhanced replication of vaccine virus in the presence of diminished immune competence. Fingolimod causes reversible sequestration of lymphocytes in lymphoid tissues. A dose-dependent reduction in peripheral lymphocyte count to 20% to 30% of baseline values has been observed, which may increase the risk of infections. Cases of generalized vaccinia and progressive vaccinia have been reported in HIV patients who received the smallpox vaccine. Vaccination may also be less effective during and for up to two months after discontinuation of fingolimod therapy.

MANAGEMENT: Routine, nonemergency smallpox vaccination is contraindicated in patients receiving immunosuppressive therapy including fingolimod. Vaccination should be avoided during and for two months after treatment with fingolimod. In patients who have recently been vaccinated, fingolimod therapy should be postponed for one month to allow the full effect of vaccination to occur. Household contacts of immunosuppressed patients should also not be vaccinated. However, there are no absolute contraindications to vaccination if a high-risk exposure has occurred. In an outbreak emergency, smallpox vaccine is recommended for all persons, regardless of medical conditions. The risk for experiencing serious complications from the vaccine should be weighed against the risk of acquiring a potentially fatal smallpox infection.