Antithrombin III deficiency (abbreviated ATIII deficiency) is a deficiency of antithrombin III. This deficiency may be inherited or acquired. It is a rare hereditary disorder that generally comes to light when a patient suffers recurrent venous thrombosis and pulmonary embolism, and repetitive intrauterine fetal death (IUFD). Hereditary antithrombin deficiency results in a state of increased coagulation which may lead to venous thrombosis. Inheritance is usually autosomal dominant, though a few recessive cases have been noted. The disorder was first described by Egeberg in 1965. The causes of acquired antithrombin deficiency are easier to find than the hereditary deficiency.The prevalence of antithrombin deficiency is estimated at ~0.02 to 0.2% of the general population, and 1-5% of patients with venous thromboembolism. There is an elevated risk of thrombosis, whereby 50% patients with AT deficiency were found to have venous thromboembolism by age 50. Cause
Diagnosis
A clinical suspicion for antithrombin deficiency can be made in patients with: 1. recurrent venous thromboembolic disease, 2. childhood thrombosis, 3. thrombosis in pregnancy. Testing for antithrombin activity can confirm deficiency if the levels are less than 70%. Deficiency can result from genetic predisposition or from acquired causes such as: acute thrombosis, disseminated intravascular coagulopathy, liver disease, nephrotic syndrome, asparaginase deficiency, oral contraception/estrogens. Genetic testing for abnormalities of the SERPINC1 gene can be done to evaluate further. Management
In patients with antithrombin deficiency, they may develop resistance to unfractionated heparin, especially with continuous infusions. If large quantities of unfractionated heparin are required e.g. greater than 35000 units per day, this would point towards resistance.
Society and culture
In 2020, generic versions were approved in the United States. Names
Salbutamol is the international nonproprietary name (INN) while albuterol is the United States Adopted Name (USAN). The drug is usually manufactured and distributed as the sulfate salt (salbutamol sulfate). It was first sold by Allen & Hanburys (UK) under the brand name Ventolin, and has been used for the treatment of asthma ever since. The drug is marketed under many names worldwide. Doping
As of 2011 there was no evidence that an increase in physical performance occurs after inhaling salbutamol, but there are various reports for benefit when delivered orally or intravenously. In spite of this, salbutamol required "a declaration of Use in accordance with the International Standard for Therapeutic Use Exemptions" under the 2010 WADA prohibited list. This requirement was relaxed when the 2011 list was published to permit the use of "salbutamol (maximum 1600 micrograms over 24 hours) and salmeterol when taken by inhalation in accordance with the manufacturers recommended therapeutic regimen. "Abuse of the drug may be confirmed by detection of its presence in plasma or urine, typically exceeding 1,000 ng/mL.