Background Tocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients. Methods A multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival. Results In the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6–24.0, P = 0.52) and 22.4% (97.5% CI: 17.2–28.3, P < 0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline. Conclusions Tocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline. Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092).

Diphenidine is a dissociative drug that shows several psychotropic effects including euphoria, shifts in perception of reality, hallucinations, and transient anterograde amnesia. In this study, a case of acute intoxication occurring after diphenidine intake is reported. A 30-year-old Caucasian male was hospitalized after he was found in a confused and agitated state and unable to communicate. The physical examination displayed tachycardia, miotic pupils, and increased both body temperature and respiratory rate. After a liquid-liquid extraction procedure, GC/MS analysis revealed the presence of diphenidine in plasma and urine at concentrations of 308 and 631 ng/mL, respectively. Methylphenidate and diclazepam were also detected in the plasma. The clinical progress of the patient was favorable, and his symptoms were cured with a symptomatic treatment. The combined circumstantial elements and toxicological results of the case reported revealed the occurrence of an acute intoxication ascribable to the recreational abuse of diphenidine.

Following publication of the original article [1] the authors identified that the collaborators of the TOCIVID-19 investigators, Italy were only available in the supplementary file. The original article has been updated so that the collaborators are correctly acknowledged.For clarity, all collaborators are listed in this correction article.