Antithrombotic drug Brilinta (Ticagrelor) and anti-influenza drug Oseltamivir ensure normal platelet aggregation during microbial blood infection. This helps prevent the development of complications and speed up recovery.
Sepsis is a powerful adverse reaction following microbial contamination. The condition can be complicated by the loss of functionality of several organs at once, which leads to a lethal outcome. The mortality rate for sepsis is about 25%. The most common causative agent of a septic reaction is Staphylococcus aureus .
Antibiotic therapy is usually prescribed for sepsis, which, however, does not always become effective. Employees at the University of California San Diego suggested supplementing therapy with other drugs. They reported this on the pages of Science Translational Medicine.
Scientists examined the medical records of about fifty patients with septic staphylococcal conditions. They noted that the positive outcomes of the disease were largely associated with the level of platelets. At a low level (less than 100 thousand per 1 mm3 of blood), an increased mortality rate (about 30%) was observed, while in patients with an indicator of more than 100 thousand per 1 mm3 of blood, mortality was only 6%.
Platelets play a role not only in blood clotting processes. They secrete antibacterial peptides that activate the immune defense against germs. In this case, staphylococcus aureus secretes the protein substance α-toxin, which damages cell membranes and activates an enzyme that removes sialic acid from the platelet surface. This process leads to the fact that platelets begin to be actively removed from the circulatory system as defective. As a result, immunity is not stimulated, sepsis increases, the patient's condition worsens.
The task of scientists was to search for drugs that can withstand the adverse effects of α-toxin. These drugs were Ticagrelor and Oseltamivir (Tamiflu, Flucap). Ticagrelor inhibits platelet adhesion and thrombus formation, and also inactivates α-toxin, preventing it from removing sialic acid from platelets. Oseltamivir blocks the enzyme, which allows platelets to remain in the bloodstream even with high levels of α-toxin.
Both drugs, in addition to clinical efficacy, have some side effects. Therefore, experts have yet to figure out the optimal dosage of these medicines to combat the development of a septic condition without serious side effects. In addition, scientists need to determine how successful the use of Ticagrelor and Oseltamivir will be in sepsis provoked by other bacterial pathogens, not just Staphylococcus aureus. Therefore, further research is still ongoing. It is quite possible that in the near future the well-known drugs will be repurposed.
Primary Source of Information: Science Translational Medicine