Neurotoxicity of polymyxins is a side effect of concern that is less known in comparison to nephrotoxicity. The symptoms consist of a wide range of mild to severe, from simple paresthesia to neuromuscular blockade of respiratory symptoms and apnea. The goal of this review is collecting the data about neurotoxicity of polymyxins and description of clinical course of incidence of this side effect. All clinical trials, prospective, retrospective, case series and case reports containing the key words “neurotoxicity”, “polymyxin”, “polymyxin B”, and “colistin” were evaluated. Clinical course of the side effect was assessed and reported. Also, the studies which report no occurrence of the side effect were also evaluated. A total of 36 articles were found that have reported neurotoxic effects of polymyxins. Total cases were 264 patients and the most reported symptoms was paresthesia and tingling, especially in facial and perioral area. Dizziness, weakness, altered mental status, and seizure was also reported. The sample size of the articles that report neurotoxicity and the one that did not detect it (twenty-six investigations) were all accumulated. A frequency of 7.64% is calculated for this side effect. The data about rechallenge or adjustment of dose is still lacking. The most prevalent symptom of neurotoxicity of polymyxin is paresthesia. More serious side effects like seizure and apnea can happen. Most of the cases has happened after loading dose. The incidence of the adverse effect is estimated as 7.64%. Rechallenge of polymyxin is still a field of question.

Abstract Introduction Severe COVID-19 management is still challenging. Having a laboratory factor to predict the severity of a patient’s condition can be very useful in how to approach each patient. There have been studies concentrating on the correlation between serum C-reactive protein (CRP) level and COVID-19 severity but we aim to reach a threshold for CRP in disease severity determination. Methods We conducted a thorough search on PubMed, Web of Science and Google Scholar databases, and 323 studies were assessed for eligibility in three phases. The T-test was applied for the CRP level cutoffs. Results Eventually, 11 articles and 1615 patients were included in this systematic review. Our analysis evaluated combined mean, median, and standard deviation of severe patients’ CRP to be respectively 73.37, 53.80 and 47.936. Based on the combined mean, 75mg/dl was suggested as an initial threshold for baseline CRP in hospitalized patients for developing severe conditions. Conclusion This study recommends that COVID-19 patients with on-admission serum CRP levels of 75 mg/dl and more are likely associated with severe conditions. Thus, anti-inflammatory agents and further following may be helpful in these patients.