In 2017 these medications cost between 5,700 and 14,000 US$ per dose in the United States, prices that tripled in two years. In those given icatibant, specialists monitor is recommended. Acquired
In acquired angioedema, HAE types I and II, and nonhistaminergic angioedema, antifibrinolytics such as tranexamic acid or ε-aminocaproic acid may be effective. Cinnarizine may also be useful because it blocks the activation of C4 and can be used in patients with liver disease, whereas androgens cannot. Prophylaxis
Future attacks of HAE can be prevented by the use of androgens such as danazol, oxandrolone or methyltestosterone. These agents increase the level of aminopeptidase P, an enzyme that inactivates kinins; kinins (especially bradykinin) are responsible for the manifestations of angioedema. In 2018, the U.S. Food and Drug Administration approved lanadelumab, an injectable monoclonal antibody, to prevent attacks of HAE types I and II in people over age 12. Lanadelumab inhibits the plasma enzyme kallikrein, which liberates the kinins bradykinin and kallidin from their kininogen precursors and is produced in excess in individuals with HAE types I and II. Epidemiology
In the U.S., there are as many as 80,000 to 112,000 emergency department (ED) visits for angioedema annually, and it ranks as the top allergic disorder resulting in hospitalization. History
Heinrich Quincke first described the clinical picture of angioedema in 1882, though there had been some earlier descriptions of the condition.William Osler remarked in 1888 that some cases may have a hereditary basis; he coined the term "hereditary angio-neurotic edema".The link with C1 esterase inhibitor deficiency was proved in 1963.
Mechanism of action
Arsenic and some other heavy metals act by chelating with adjacent thiol residues on metabolic enzymes, creating a chelate complex that inhibits the affected enzymes activity. Dimercaprol competes with the thiol groups for binding the metal ion, which is then excreted in the urine.Dimercaprol is itself toxic, with a narrow therapeutic range and a tendency to concentrate arsenic in some organs. Other drawbacks include the need to administer it by painful intramuscular injection. Serious side effects include nephrotoxicity and hypertension. Dimercaprol has been found to form stable chelates in vivo with many other metals including inorganic mercury, antimony, bismuth, cadmium, chromium, cobalt, gold, and nickel. However, it is not necessarily the treatment of choice for toxicity to these metals. Dimercaprol has been used as an adjunct in the treatment of the acute encephalopathy of lead toxicity. It is a potentially toxic drug, and its use may be accompanied by multiple side effects. Although treatment with dimercaprol will increase the excretion of cadmium, there is a concomitant increase in renal cadmium concentration, so that its use in case of cadmium toxicity is to be avoided. It does, however, remove inorganic mercury from the kidneys; but is not useful in the treatment of alkylmercury or phenylmercury toxicity. Dimercaprol also enhances the toxicity of selenium and tellurium, so it is not to be used to remove these elements from the body.