Comprehensive analysis of drugs to treat SARS‑CoV‑2 infection: Mechanistic insights into current COVID‑19 therapies (Review)

The major impact produced by the severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) focused many researchers attention to find treatments that can suppress transmission or ameliorate the disease. Despite the very fast and large flow of scientific data on possible treatment solutions, none have yet demonstrated unequivocal clinical utility against coronavirus disease 2019 (COVID‑19). This work represents an exhaustive and critical review of all available data on potential treatments for COVID‑19, highlighting their mechanistic characteristics and the strategy development rationale. Drug repurposing, also known as drug repositioning, and target based methods are the most used strategies to advance therapeutic solutions into clinical practice. Current in silico, in vitro and in vivo evidence regarding proposed treatments are summarized providing strong support for future research efforts.

Antidepressant effect of the interaction of fluoxetine with granisetron

Selective serotonin reuptake inhibitors (SSRIs) may produce digestive side effects such as nausea and vomiting, diarrhoea and decreased appetite. These side effects are determined by the increase in serotonin availability at 5-HT3 receptors. Granisetron, a serotonin 5-HT3 receptor antagonist, is expected to antagonize the digestive adverse effects of serotonin reuptake inhibitors, but the question is to what extent granisetron influences the antidepressant effect of these substances. The aim of this study was to determine the dose of fluoxetine that has an antidepressant effect in the Porsolt test, and the interaction between fluoxetine and granisetron with respect to the antidepressant effect in this test. In experiment 1, fluoxetine was antidepressant only at 20 mg/kg body weight (bw). In experiment 2, granisetron 1 mg/kg bw had a statistically significant antidepressant effect vs. control. Fluoxetine 20 mg/kg bw associated with a small dose of granisetron (0.1 mg/kg bw) produced a significant antidepressant effect vs. control. This shows that low doses of granisetron associated to fluoxetine might produce a significant antidepressant effect, suggesting a potentiation between these two drugs used in sub-effective antidepressant doses. In conclusion, in our experimental conditions, we can assume that granisetron in low doses could be used to combat intestinal transit disorders produced by SSRI antidepressants. These low doses are preferred, because they increase the antidepressant effect of these SSRIs.

Topical administration of Metamizole and its implications on vascular reactivity in Wistar rats- Experimental research

Aim: The aim of this paper was to describe the possible implications of topical (ocular) administration of Metamizole on vascular reactivity of the iris in Wistar rats. No other study regarding its topical use was found. Methods: Male adult Wistar rats were anaesthetized with Ketamine 100 mg /kg body weight - injected intraperitoneally - while maintaining spontaneous respiration and the blink reflex. After selecting the area of interest (long posterior ciliary artery - LPCA), manual adjustments of the image magnitude, clarity, and brightness were made, and the experiment began. The image recording lasted 10 minutes. Results: Metamizole induced a slight vasoconstriction that started with the initial moment for all the doses used. After the topical administration of Metamizole, we did not observe an increase of the vascular diameter of LPCA in a dose dependent manner. The saline solution used as a negative control did not modify the vessel diameter. Conclusions: Metamizole (dipyrone) is a non-opioid drug, which is commonly used in human and veterinary medicine. It is the most popular first-line analgesic in various populations. In some cases, this agent is still incorrectly classified as a non-steroidal anti-inflammatory drug. The high analgesic efficacy of metamizole, as well as its spasmolytic effect, makes it a very important pharmaceutical agent that could be used in the therapy of various eye disorders in humans and in animals. Abbreviations: COX = Cyclooxygenase; LPCA = Long Posterior Ciliary Artery; PRP = panretinal photocoagulation; PDR = proliferative diabetic retinopathy; Sec = second(s); VSPR = very severe non proliferative diabetic retinopathy.