Trends in Treatments With Disease-Specific and Interfering Drugs in Patients With Hereditary Angioedema in Sweden

BACKGROUND: Hereditary angioedema (HAE) is caused by low levels of or defects in C1 inhibitor. Although disease activity may be modified by prophylaxis, emergency treatment, treatment for comorbidities, and oral contraceptives, the extent of their use is unclear. OBJECTIVE: To investigate trends in the use of disease-specific and interfering drugs in patients with HAE compared with the general population in Sweden. METHODS: In a nationwide, longitudinal study, 239 patients with HAE and 2 383 controls were compared with the Prescribed Drug Register (2005-2019). These data reflect rates of dispensed prescriptions from pharmacies in Sweden. RESULTS: Attenuated androgens were used by approximately 10% of patients with HAE. The number of individuals treated with prophylactic plasma-derived C1 inhibitor increased during this period to reach almost 25% in men and 35% in women in 2019. Tranexamic acid was prescribed to 5% to 15% of patients, primarily children and young adults. Rates of prescriptions for icatibant, an emergency medication, showed a steady increase since its introduction in 2010, in particular among middle-aged women, suggesting poorly controlled disease. The use of diuretics, calcium channel blockers, and gestagens was more common in patients with HAE than in controls, whereas angiotensin-converting enzyme inhibitors were rarely collected. CONCLUSIONS: Despite concerns regarding side effects, approximately 10% of patients with HAE received attenuated androgens for long-term prophylaxis. The common use of emergency medication also suggests poorly controlled disease in many patients, highlighting the need for increased focus on prophylactic treatment.