Thymoglobulin (manufactured by Sanofi) is an anti-human thymocyte immunoglobulin preparation made of purified polyclonal antibodies derived from rabbits. While these antibodies have a variety of specificities, their main mechanism of immunosuppression is through depletion of T cells. Thymoglobulin is currently approved for clinical use in Europe and the United States for renal allograft rejection, prevention of graft-vs.-host disease, and conditions involving bone marrow failure, including aplastic anemia and has additional off-label uses. History of antithymocyte globulin
Antithymocyte globulin (ATG) was originally developed as one of various tested preparations of antilymphocyte globulin (ALG) specifically generated against human lymphocytes within the thymus, or thymocytes. The purpose of this research was largely to produce an effective immunosuppressive agent safe for use in humans. Since the discovery of a link between antilymphocyte serum (ALS) and lymphocyte depletion by Metchnikoff in 1899, various studies have demonstrated the immunosuppressive ability of ALG and ATG. Experiments on ALS that confirmed its efficacy in lymphocyte depletion led to testing of different types of preparations including ALG, which were ALS produced against human lymphocytes, and ATG.A number of studies conducted in the 1960s, including studies by Starzl et al. and Mathe et al., resulted in promising data for the clinical use of ALG for preserving short-term and long-term kidney function in patients immediately after human kidney transplantation. Use of equine ALG was also found to be efficacious in preventing acute graft-vs.-host-disease in patients’ post-allogeneic bone marrow transplantation.
It is thought that bimatoprost mimics the human bodys own prostamides (which are chemically similar), a class of substances related to prostaglandins, but with an unknown mechanism of action. No prostamide receptor has been identified as of 2015; the search is ongoing. As of 2019 it was thought that bimatoprost worked via the trabecular meshwork and uveoscleral pathways. Pharmacokinetics
Bimatoprost is well absorbed through the cornea. It starts lowering intraocular pressure after four hours, lasting for at least 24 hours. A low percentage enters the bloodstream. In the blood plasma, peak concentrations are reached after 10 minutes, then drop below the detection limit of 25 pg/ml after 1.5 hours. The substance does not accumulate in the body.Plasma protein binding is 88%. Bimatoprost is metabolized by oxidation, N-deethylation and glucuronidation, forming a variety of metabolites. Biological half-life was measured to be 45 minutes after intravenous infusion. 67% are eliminated via the kidney, and 25% via the feces. References
Further reading
"Prostaglandin Analogues for Ophthalmic Use: A Review of the Comparative Clinical Effectiveness and Cost-Effectiveness". CADTH Rapid Response Reports. July 2015. PMID 26985536. External links
"Bimatoprost". Drug Information Portal. U.S. National Library of Medicine.