Drug-induced splenomegaly refers to enlargement of the spleen, often to over 400-500 g or 11 cm in widest diameter, attributed to the initiation of a new medication or drug. Patients with splenomegaly are typically asymptomatic, and this diagnosis is frequently detected on examination with a palpable spleen or incidentally on imaging. In some instances, patients can have vague left-sided abdominal pain, early satiety, or can present with signs of anemia (ie, pallor, fatigue) if the splenomegaly is due to hemolysis.

Drug-induced splenomegaly can occur due to a direct hypertrophic effect on splenic cells or due to an effect on other organ systems (ie, hemolysis, portal hypertension) leading to splenic enlargement. Chemotherapeutic drugs (eg, oxaliplatin, fluorouracil, bevacizumab, etc) are often implicated in drug-induced splenomegaly. RhoGAM is also known to cause splenomegaly in some patients.

For a more exhaustive list of medications associated with splenomegaly, see Drug Reaction Data below.