Cardiovascular and Renal Actions of Cytochrome P-450 Metabolites of Arachidonic Acid

Cytochrome P-450 is the terminal oxidase of the electron transport chain in the endoplasmic reticulum. Arachidonic acid (AA) can be oxidatively metabolized by cytochrome P-450 hemoproteins to an array of compounds identified as constituents of tissues and biological fluids. Their synthesis can be manipulated by pharmacologic probes and are altered in pathophysiologic conditions. These novel eicosanoids stimulate release of peptide and steroid hormones, inhibit platelet and leukocyte aggregation, influence Na+-K+-ATPase and alter vasomotor tone. They also participate in fluid and electrolyte homeostasis, stimulus-secretion coupling, and regulation of tissue blood flow. Since these novel AA metabolites may participate in receptor-mediated signal transduction, and have been implicated in the generation of second messengers and changes in intracellular calcium, these studies have important implications for understanding basic biological mechanisms

Erratum: Renal Impairment and Clinical Outcomes of <i>Clostridium difficile</i> Infection in Two Randomized Trials

<b><i>Background/Aims:</i></b> Patients with chronic kidney disease (CKD) have increased risk for <i>Clostridium difficile</i> infection (CDI) and for subsequent mortality. We determined the effect of CKD on response to treatment for CDI. <b><i>Methods:</i></b> This is a post hoc analysis of two randomized controlled phase 3 trials that enrolled patients with CDI. Patients received either fidaxomicin 200 mg b.i.d. or vancomycin 125 mg q.i.d. for 10 days. Univariate and multivariate analyses compared end points by treatment received and CKD stage. <b><i>Results:</i></b> At baseline, 27, 21, and 9% of the patients had stage 2 (60-89 ml/min/1.73 m²), stage 3 (30-59), and stage 4 or higher (<30) CKD. Cure rates were similar for normal (91%) and stage 2 CKD (92%), but declined to 80% for stage 3 and to 75% for stage 4 CKD (p < 0.001 for trend). Time to resolution of diarrhea (TTROD) increased with stage 3 and stage 4 CKD. CDI recurrence rates 4 weeks after treatment were 16, 20, 27, and 24% for normal, stage 2, stage 3, and stage 4 or higher CKD, respectively. Mortality increased with CKD stage. In multivariate analyses, stage 3 or higher CKD correlated with lower odds of cure, greater chance of recurrence, and lower odds of sustained response 28 days after treatment. Initial cure rates were similar in the vancomycin or fidaxomicin groups; however, the rate of recurrence was higher following vancomycin treatment independent of renal function. The presence of immunosuppression did not alter this effect. <b><i>Conclusion:</i></b> Progressive CKD is associated with increased TTROD, lower cure rates, and higher recurrence rates with treatment of CDI

Remdesivir for 5 or 10 Days in Patients with Severe Covid-19

Background Remdesivir is an RNA polymerase inhibitor with potent antiviral activity in vitro and efficacy in animal models of coronavirus disease 2019 (Covid-19). Methods We conducted a randomized, open-label, phase 3 trial involving hospitalized patients with confirmed SARS-CoV-2 infection, oxygen saturation of 94% or less while they were breathing ambient air, and radiologic evidence of pneumonia. Patients were randomly assigned in a 1:1 ratio to receive intravenous remdesivir for either 5 days or 10 days. All patients received 200 mg of remdesivir on day 1 and 100 mg once daily on subsequent days. The primary end point was clinical status on day 14, assessed on a 7-point ordinal scale. Results In total, 397 patients underwent randomization and began treatment (200 patients for 5 days and 197 for 10 days). The median duration of treatment was 5 days (interquartile range, 5 to 5) in the 5-day group and 9 days (interquartile range, 5 to 10) in the 10-day group. At baseline, patients randomly assigned to the 10-day group had significantly worse clinical status than those assigned to the 5-day group (P=0.02). By day 14, a clinical improvement of 2 points or more on the ordinal scale occurred in 64% of patients in the 5-day group and in 54% in the 10-day group. After adjustment for baseline clinical status, patients in the 10-day group had a distribution in clinical status at day 14 that was similar to that among patients in the 5-day group (P=0.14). The most common adverse events were nausea (9% of patients), worsening respiratory failure (8%), elevated alanine aminotransferase level (7%), and constipation (7%). Conclusions In patients with severe Covid-19 not requiring mechanical ventilation, our trial did not show a significant difference between a 5-day course and a 10-day course of remdesivir. With no placebo control, however, the magnitude of benefit cannot be determined. (Funded by Gilead Sciences; GS-US-540-5773 ClinicalTrials.gov number, NCT04292899. opens in new tab.

Oxygen free radicals and congestive heart failure.

Plasma lipid peroxides (malondialdehyde) and thiols were measured in 45 patients with congestive heart failure and 45 controls. Malondialdehyde concentrations were significantly higher in the patients with congestive heart failure (median 9.0 nmol/ml interquartile range (IQR) 7.9-10.2) than in the controls (median 7.7 nmol/ml (IQR 6.9-9.2)). Plasma thiols were significantly lower in congestive heart failure (median 420 mumol/l (IQR 379-480)) than in the controls (median 463 mumol/l (IQR 445-525)). There was a significant but weak negative correlation between malondialdehyde and left ventricular ejection fraction (r = -0.35) and a positive correlation between plasma thiols and left ventricular ejection fraction (r = 0.39). This study provides clinical support for experimental data indicating that free radicals may be important in heart failure. It also suggests that the degree of free radical production may be linked to the severity of the disease

Effect of Remdesivir vs Standard Care on Clinical Status at 11 Days in Patients With Moderate COVID-19 A Randomized Clinical Trial

IMPORTANCE Remdesivir demonstrated clinical benefit in a placebo-controlled trial in patients with severe coronavirus disease 2019 (COVID-19), but its effect in patients with moderate disease is unknown.OBJECTIVE To determine the efficacy of 5 or 10 days of remdesivir treatment compared with standard care on clinical status on day 11 after initiation of treatment.DESIGN, SETTING, AND PARTICIPANTS Randomized, open-label trial of hospitalized patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and moderate COVID-19 pneumonia (pulmonary infiltrates and room-air oxygen saturation >94%) enrolled from March 15 through April 18, 2020, at 105 hospitals in the United States, Europe, and Asia. The date of final follow-up was May 20, 2020.INTERVENTIONS Patients were randomized in a 1:1:1 ratio to receive a 10-day course of remdesivir (n = 197), a 5-day course of remdesivir (n = 199), or standard care (n = 200). Remdesivir was dosed intravenously at 200 mg on day 1 followed by 100 mg/d.MAIN OUTCOMES AND MEASURES The primary end point was clinical status on day 11 on a 7-point ordinal scale ranging from death (category 1) to discharged (category 7). Differences between remdesivir treatment groups and standard care were calculated using proportional odds models and expressed as odds ratios. An odds ratio greater than 1 indicates difference in clinical status distribution toward category 7 for the remdesivir group vs the standard care group.RESULTS Among 596 patients who were randomized, 584 began the study and received remdesivir or continued standard care (median age, 57 [interquartile range, 46-66] years; 227 [39%] women; 56% had cardiovascular disease, 42% hypertension, and 40% diabetes), and 533 (91%) completed the trial. Median length of treatment was 5 days for patients in the 5-day remdesivir group and 6 days for patients in the 10-day remdesivir group. On day 11, patients in the 5-day remdesivir group had statistically significantly higher odds of a better clinical status distribution than those receiving standard care (odds ratio, 1.65; 95% CI, 1.09-2.48; P =.02). The clinical status distribution on day 11 between the 10-day remdesivir and standard care groups was not significantly different (P =.18 by Wilcoxon rank sum test). By day 28, 9 patients had died: 2 (1%) in the 5-day remdesivir group, 3 (2%) in the 10-day remdesivir group, and 4 (2%) in the standard care group. Nausea (10% vs 3%), hypokalemia (6% vs 2%), and headache (5% vs 3%) were more frequent among remdesivir-treated patients compared with standard care.CONCLUSIONS AND RELEVANCE Among patients with moderate COVID-19, those randomized to a 10-day course of remdesivir did not have a statistically significant difference in clinical status compared with standard care at 11 days after initiation of treatment. Patients randomized to a 5-day course of remdesivir had a statistically significant difference in clinical status compared with standard care, but the difference was of uncertain clinical importance.Host-parasite interactio