Interferon alfa-2b is an antiviral or antineoplastic drug. It is a recombinant form of the protein Interferon alpha-2 that was originally sequenced and produced recombinantly in E. coli in the laboratory of Charles Weissmann at the University of Zurich, in 1980. It was developed at Biogen, and ultimately marketed by Schering-Plough under the trade name Intron-A. It was also produced in 1986 in recombinant human form, in the Center for Genetic Engineering and Biotechnology of Havana, Cuba, under the name Heberon Alfa R.It has been used for a wide range of indications, including viral infections and cancers. This drug is approved around the world for the treatment of chronic hepatitis C, chronic hepatitis B, hairy cell leukemia, Behçets disease, chronic myelogenous leukemia, multiple myeloma, follicular lymphoma, carcinoid tumor, mastocytosis and malignant melanoma.The medication is being used in clinical trials to treat patients with SARS-CoV-2 and there are published results in the peer-reviewed scientific literature.So far, two non-peer reviewed research articles have been published. One study at the University of Texas Medical Branch, Galveston, showed evidence of a direct anti-viral effect of Interferon alpha against novel Coronavirus in vitro. The study demonstrated around 10,000 fold reduction in the quantity of virus that was pre-treated with Interferon alpha 48 hours earlier. A second study by universities in China, Australia and Canada analysed 77 moderate COVID-19 subjects in Wuhan and observed that those who received Interferon alpha-2b showed a significant reduction in the duration of virus shedding period and even in levels of the inflammatory cytokine, IL-6.
Emedastine (trade name Emadine) is a second generation antihistamine used in eye drops to alleviate the symptoms of allergic conjunctivitis. It acts as a H1 receptor antagonist. It works by blocking the action of histamine that causes allergic symptoms. It is used in form of the difumarate. The emedastine difumarate is a white, crystalline, water-soluble fine powder. Emedastine eye drops is usually applied twice a day to the affected eye. When the patients with allergic conjunctivitis were treated with 0.05% emedastine difumarate ophthalmic solution for six weeks, the signs and symptoms such as redness, itching and swelling of the eyes were relieved. Emedastine appears to be devoid of effects on adrenergic, dopaminergic and serotonin receptors. This drug was developed by Alcon, which is global medical company specializing in eye care products. Pharmacodynamics
Emedastine is significantly selective to H1 histamine receptors (Ki = 1.3 nM), whereas its affinities for other histamine receptors were low (H2: Ki = 49067 nM and H3: Ki = 12430 nM) ub in vitro study. Topical ocular administration of emedastine inhibits histamine-stimulated vascular permeability in the conjunctiva as a concentration-dependent manner in in vitro study. Pharmacokinetics
The human oral bioavailability is approximately 50% and maximum plasma concentration was achieved within 1–2 hours after dosing. Emedastine is mainly metabolized by the liver. There are two primary metabolites: 5-hydroxyemedastine and 6-hydroxyemedastine. They are excreted in the urine as both free and conjugated forms. The 5-oxoanalogs of 5-hydroxyemedastine, 6-hydroxyemedastine and the N-oxide are also formed as minor metabolites.