Successful treatment of refractory anaphylactic shock with angiotensin II

Refractory anaphylaxis is a severe form of anaphylaxis, defined as anaphylaxis requiring ongoing treatment despite two appropriate doses of epinephrine. There is a lack of data about second-line vasopressor treatment in refractory anaphylaxis. We present a case report of refractory anaphylaxis after a young female received a gadolinium-based contrast medium and was successfully treated with an angiotensin II (ATII) infusion. ATII is converted from angiotensin I by the action of the angiotensin-converting enzyme (ACE). Since oestrogen has an inhibitory effect upon mRNA synthesis of ACE, premenopausal women have lower ACE and ATII levels, making them more prone to anaphylaxis. There are also gene polymorphisms related to lower ATII levels in patients with severe anaphylaxis. Since ATII has no effect on mastocytes and bronchospasm, it can only be used as a second-line vasopressor beside epinephrine and fluid treatment in refractory anaphylaxis.