Unpredictability of Attacks

FIRAZYR is indicated for the treatment of acute attacks of hereditary angioedema (HAE) in adults 18 years of age and older.
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Unpredictability of HAE attacks

Acute attacks of HAE are unpredictable in terms of frequency and severity.1


Triggers – Some attacks can be traced to specific triggers. These may include1,2:

  • Trauma
  • Medical and dental procedures
  • Hormonal changes
  • Emotional stress
  • Minor physical activities

However, many attacks occur with no apparent precipitating event.1



Frequency – Attack frequency varies from patient to patient and even within the same patient. Acute attacks may occur as often as several times per week or as infrequently as once or twice a year.2,3 A 2007 survey found that patients experienced a median of 12 attacks and a mean of 27 attacks per year.1



Severity – HAE attacks can be highly variable and unpredictable.1 In most cases, untreated HAE attacks are transient, progressing over 24 hours and then subsiding during the next 2 to 3 days. However, some patients may experience peripheral swelling attacks that last more than a week.4,5 Attacks also can start in one location and then migrate to another before resolving.6

Laryngeal attacks pose the greatest risk and put patients in danger of asphyxiation.7,8 About fifty percent of HAE patients experience at least one laryngeal attack in their lifetime.7* Historically, untreated laryngeal attacks resulted in a mortality rate up to 30%.2 †

*In a survey of 209 patients

Based on genealogical information from 226 patients