Pulmonary embolism in patients with multiple sclerosis treated with teriflunomide: A series of three cases.

Teriflunomide is an oral disease modifying therapy for patients with relapsing remitting multiple sclerosis. It is moderately effective while having a favourable safety profile with liver toxicity being the major concern. We present a series of three patients who developed pulmonary embolism within two years of initiation of teriflunomide treatment. They had stable multiple sclerosis with low level of disability, with immobility presenting a negligible risk for the development of pulmonary embolism. The estimated prevalence of pulmonary embolism in our cohort is 2.8%. Thus, we believe additional attention to the general risk factors for PE is warranted before teriflunomide is introduced to patients with multiple sclerosis.