Chronic hyponatremia is often called asymptomatic hyponatremia in clinical settings because it is thought to have no symptoms; however, emerging data suggests that "asymptomatic" hyponatremia is not actually asymptomatic.Acute hyponatremia is when sodium levels drop rapidly, resulting in potentially dangerous effects, such as rapid brain swelling, which can result in coma and death. Treatment
The treatment of hyponatremia depends on  the underlying cause. How quickly treatment is required depends on a persons symptoms. Fluids are typically the cornerstone of initial management. In those with severe disease an increase in sodium of about 5 mmol/L over one to four hours is recommended. A rapid rise in serum sodium is anticipated in certain groups when the cause of the hyponatremia is addressed thus warranting closer monitoring in order to avoid overly rapid correction of the blood sodium concentration. These groups include persons who have hypovolemic hyponatremia and receive intravenous fluids (thus correcting their hypovolemia), persons with adrenal insufficiency who receive hydrocortisone, persons in whom a medication causing increased ADH release has been stopped, and persons who have hyponatremia due to decreased salt and/or solute intake in their diet who are treated with a higher solute diet.
The amount of circulating IgG decreases and therefore prevents the acetylcholine receptors from being degraded by the autoantibodies that are responsible for the myasthenia gravis. Pharmacokinetics
The drug is mainly metabolized via proteolytic enzymes. The termination half-life of Efgartigimod alfa is 80 to 120 hours. Side effects
Side effects of efgartigimod alfa include respiratory tract infections, headache, urinary tract infection, numbness and tingling and muscle pain. Society and culture
Legal status
The U.S. Food and Drug Administration (FDA) granted the application for efgartigimod alfa fast track and orphan drug designations. The FDA granted the approval of Vyvgart to Argenx BV.On 23 June 2022, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Vyvgart, intended for the treatment of anti‑acetylcholine receptor (AChR) antibody positive generalized myasthenia gravis. The applicant for this medicinal product is Argenx. Efgartigimod alfa was approved for medical use in the European Union in August 2022. Names
Efgartigimod alfa is the international nonproprietary name (INN). References
This article incorporates public domain material from the United States Department of Health and Human Services. Further reading
Howard JF, Bril V, Vu T, Karam C, Peric S, Margania T,  et al. (July 2021). "Safety, efficacy, and tolerability of efgartigimod in patients with generalised myasthenia gravis (ADAPT): a multicentre, randomised, placebo-controlled, phase 3 trial". Lancet Neurol. 20 (7): 526–536. doi:10.1016/S1474-4422(21)00159-9. hdl:10067/1859580151162165141. PMID 34146511. S2CID 235456637. External links
"Efgartigimod alfa". Drug Information Portal. U.S. National Library of Medicine.