Long term preventative treatment – Prophylaxis

The frequency and severity of attacks of angioedema can be reduced by attenuated androgens such as Danazol and Oxandrolone, or by Tranexamic Acid. Your doctor will discuss these treatments with you.

Preventative Medications – drugs used to reduce the incidence and severity of an attack


Danazol may be used to reduce the level of HAE attacks. However, Danazol is an attenuated androgen which may cause unacceptable side effects, particularly in females. It is important to keep the doses of the medication as low as possible, and side effects should be reported as they are usually reversible if danazol is stopped promptly.

Possible side effects of danazol


Oxandrolone is also an attenuated androgen that is used to reduce the level of HAE attacks. Oxandrolone may be helpful even if Danazol has not been effective, or if Danazol has not been well tolerated.

Attenuated androgens, if used wisely, can be well tolerated even in women, and can improve quality of life for HAE patients. Attenuated androgens should not be used in pregnancy or for children.

Tranexamic Acid

Tranexamic Acid can be used in children and adults in an effort to reduce the number of attacks of angioedema. Even if prophylactic medications are used, patients may still get a severe breakthrough attack, so it is important to always have an emergency plan in place.

Maintenance therapy using C1 Inhibitor concentrate

Occasionally regular injections of C1 Inhibitor may be needed as a preventative measure.

The use of regular injections of C1 Inhibitor may be recommended in:

  • Cases of frequent severe attacks of angioedema where attenuated androgens are insufficient or unacceptable
  • In frequent severe attacks in pregnancy
  • In severe HAE in children

Another form of prophylaxis which may be offered to patients suffering frequent attacks is:

Lanadelumab – trade name Takhzyro

This is a man-made ‘monoclonal antibody’ treatment which targets specific blood proteins that can cause swelling in HAE.

It is given as a once a fortnight subcutaneous (under the skin) injection. Once good control is established, many patients can step down to one injection per month. It is licensed for 12 years old and over.

Click here for information about Lanadelumab


There is an oral product called Berotralstat which is at present available in UK under an Early Access Medicine Scheme (EAMS). This is taken once per day to prevent and reduce attacks of HAE. Some people are being prescribed this by their Immunology team, but as yet it is not widely available.   

Click here for information about EAMS

Home therapy for HAE patients

Suitable patients who get frequent severe attacks of HAE will be offered training to give their acute attack medications at home.

See Clinical Commissioning Policy: Treatment of Acute Attacks in Hereditary Angioedema. This provision for home therapy applies to both adults and children.

2013 Clinical Commissioning Policy: Treatment of Acute Attacks in Hereditary Angioedema

2014 UK Revised Consensus Guidelines for the Management of Hereditary Angioedema