Evaluating the elimination status of medications used for COVID-19 during hemoperfusion and therapeutic plasma exchange: A review.

Since late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, better known as COVID-19) has rapidly spread worldwide. The primary pathophysiology by which COVID-19 leads to severe lung damage is cytokine releasing syndrome (CRS), which can cause death. Therefore, removing cytokines via therapeutic plasma exchange or hemoperfusion could be a therapeutic approach to treat CRS. However, hemoperfusion or therapeutic plasma exchange could alter the effectiveness of concomitant medications. Thus, concomitant medication doses might need to be adjusted to prevent their elimination via therapeutic plasma exchange or hemoperfusion, thus ensuring that these medications remain effective. This narrative review investigates the elimination status of current medications used to manage COVID-19 during hemoperfusion and therapeutic plasma exchange, with a focus on their pharmacokinetic profiles.

Aerosol Inhalation Delivery of Triazavirin in Mice: Outlooks for Advanced Therapy Against Novel Viral Infections.

Under pandemic-caused emergency, evaluation of the potential of existing antiviral drugs for the treatment of COVID-19 is relevant. Triazavirin, an antiviral drug developed in Russia for per-oral administration, is involved in clinical trials against SARS-CoV-2 coronavirus. This virus has affinity to epithelial cells in respiratory tract, so drug delivery directly in lungs may enhance therapeutic effect and reduce side effects for stomach, liver, kidneys. We elaborated ultrasonic method of triazavirin aerosol generation and investigated the inhalation delivery of this drug in mice. Mean particle size and number concentration of aerosol used in inhalation experiments are 560 nm and 4 × 105 cm-3, respectively. Aerosol mass concentration is 1.6 × 10-4 mg/cm3. Inhalation for 20 min in a nose-only chamber resulted in 2 mg/kg body delivered dose and 2.6 µg/mL triazavirin concentration in blood plasma. Elimination rate constant determined in aerosol administration experiments was ke = 0.077 min-1, which agrees with the value measured after intravenous delivery, but per-oral administration resulted in considerably lower apparent elimination rate constant of pseudo-first order, probably due to non-linear dependence of absorption rate on triazavirin concentration in gastrointestinal tract. The bioavailability of triazavirin aerosol is found to be 85%, which is about four times higher than for per-oral administration.