This medication is used to help prevent severe swelling attacks due to a certain inherited immune disease (hereditary angioedema-HAE). Berotralstat works by binding to a natural substance made by the body (kallikrein) and blocking its effect. This blocking effect lowers the amount of another natural substance (bradykinin) that causes symptoms during an attack of HAE.
Berotralstat should not be used to treat an acute HAE attack. If an HAE attack occurs, use your usual rescue medication as prescribed.