Population Pharmacokinetics and Pharmacodynamics of Meropenem in Critically Ill Pediatric Patients.

This study investigates the optimal meropenem (MEM) dosing regimen for critically ill pediatric patients, for which there is a lack of pharmacokinetic (PK) studies. We conducted a retrospective single-center PK and pharmacodynamic (PD) analysis of 34 pediatric intensive care unit patients who received MEM. Individual PK parameters were determined by a two-compartment analysis. The median (range) age and body weight were 1.4 (0.03 to 14.6) years and 8.9 (2.7 to 40.9) kg, respectively, and eight (23.5%) patients received continuous renal replacement therapy (CRRT), three of whom received extracorporeal membrane oxygenation. Renal function, the systemic inflammatory response syndrome (SIRS) score for the clearance (CL), and the use of CRRT for the central volume of distribution (Vc) were identified as significant covariates. The mean CL, Vc, and peripheral volume of distribution (Vp) were 0.45 liters/kg/h, 0.49 liters/kg, and 0.34 liters/kg, respectively. The mean population CL of MEM increased by 35% in patients with SIRS and Vc increased by 66% in patients on CRRT in the final model. Dosing simulations suggested that the standard dosing regimen provided insufficient PD exposures of a 100% free time above the MIC, and higher doses (40 to 80 mg/kg of body weight/dose every 8 h) with a prolonged 3-h infusion were required to ensure the appropriate PD exposures for patients with SIRS. Our PK model indicated that critically ill pediatric patients are at risk of subtherapeutic exposure under the standard dosing regimen of MEM. A larger, prospective investigation confirming the safety and efficacy of higher concentrations and prolonged infusion of MEM is necessary.

High-Dose Versus Low-Dose Pitavastatin in Japanese Patients With Stable Coronary Artery Disease (REAL-CAD): A Randomized Superiority Trial.

BACKGROUND: Current guidelines call for high-intensity statin therapy in patients with cardiovascular disease on the basis of several previous "more versus less statins" trials. However, no clear evidence for more versus less statins has been established in an Asian population. METHODS: In this prospective, multicenter, randomized, open-label, blinded end point study, 13 054 Japanese patients with stable coronary artery disease who achieved low-density lipoprotein cholesterol (LDL-C) <120 mg/dL during a run-in period (pitavastatin 1 mg/d) were randomized in a 1-to-1 fashion to high-dose (pitavastatin 4 mg/d; n=6526) or low-dose (pitavastatin 1 mg/d; n=6528) statin therapy. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke, or unstable angina requiring emergency hospitalization. The secondary composite end point was a composite of the primary end point and clinically indicated coronary revascularization excluding target-lesion revascularization at sites of prior percutaneous coronary intervention. RESULTS: The mean age of the study population was 68 years, and 83% were male. The mean LDL-C level before enrollment was 93 mg/dL with 91% of patients taking statins. The baseline LDL-C level after the run-in period on pitavastatin 1 mg/d was 87.7 and 88.1 mg/dL in the high-dose and low-dose groups, respectively. During the entire course of follow-up, LDL-C in the high-dose group was lower by 14.7 mg/dL than in the low-dose group (P<0.001). With a median follow-up of 3.9 years, high-dose as compared with low-dose pitavastatin significantly reduced the risk of the primary end point (266 patients [4.3%] and 334 patients [5.4%]; hazard ratio, 0.81; 95% confidence interval, 0.69-0.95; P=0.01) and the risk of the secondary composite end point (489 patients [7.9%] and 600 patients [9.7%]; hazard ratio, 0.83; 95% confidence interval, 0.73-0.93; P=0.002). High-dose pitavastatin also significantly reduced the risks of several other secondary end points such as all-cause death, myocardial infarction, and clinically indicated coronary revascularization. The results for the primary and the secondary composite end points were consistent across several prespecified subgroups, including the low (<95 mg/dL) baseline LDL-C subgroup. Serious adverse event rates were low in both groups. CONCLUSIONS: High-dose (4 mg/d) compared with low-dose (1 mg/d) pitavastatin therapy significantly reduced cardiovascular events in Japanese patients with stable coronary artery disease. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01042730.

Individual optimal dose of amrubicin to prevent severe neutropenia in Japanese patients with lung cancer.

This study determined individual optimal amrubicin doses for Japanese patients with lung cancer after platinum-based treatment. We carried out population pharmacokinetic and pharmacodynamic modeling incorporating gene polymorphisms of metabolizing enzymes and transporters. Fifty patients with lung cancer, who were given 35-40 mg/m2 amrubicin on days 1-3 every 3-4 weeks, were enrolled. Mechanism-based modeling described relationships between the pharmacokinetics of amrubicin and absolute neutrophil counts. A population pharmacokinetic and pharmacodynamic model was developed for amrubicin and amrubicinol (active metabolite), connected by a delay compartment. The final model incorporated body surface area as a covariate of amrubicin and amrubicinol clearance and distribution volume. SLC28A3 single nucleotide polymorphism (rs7853758) was also incorporated as a constant covariate of the delay compartment of amrubicinol. Performance status was considered a covariate of pharmacokinetic (amrubicinol clearance) and pharmacodynamic (mean maturation time) parameters. Twenty-nine patients with grade 4 neutropenia showed higher amrubicinol area under the plasma concentration-time curve from 0 to 72 hours (AUC0-72 , P = .01) and shorter overall survival periods than other patients did (P = .01). Using the final population pharmacokinetic and pharmacodynamic model, median optimal dose to prevent grade 4 neutropenia aggravation was estimated at 22 (range, 8-40) mg/m2 for these 29 patients. We clarified correlations between area under the plasma concentration-time curve from 0 to 72 hours of amrubicinol and severity of neutropenia and survival of patients given amrubicin after platinum chemotherapy. This analysis revealed important amrubicin pharmacokinetic-pharmacodynamic covariates and provided useful information to predict patients who would require prophylactic granulocyte colony stimulating factor.

[Aortic root and arch replacement late after ascending aortic replacement for acute aortic dissection; report of a case].

Surgical treatment for acute type A aortic dissection remains controversial, especially when the aortic dissection extends to the aortic root and arch. A 73-year-old woman presented with palpitation. She had previously undergone ascending aorta replacement for acute type A aortic dissection with reinforcement of the proximal and distal aortic stumps using gelatin-resorcinol-formaldehyde (GRF) glue, conducted by a different surgical team 7 years ago. Echocardiography and computed tomography revealed dilatation of both ends of the reconstructed aorta, with aortic valve insufficiency. Hence, we performed Bentall procedure, partial aortic arch replacement, and coronary artery bypass grafting. The postsurgical course was uneventful. Redo operations may be avoidable, if, in the initial operation for acute type A aortic dissection with dissected aortic root and arch, surgery is performed without use of GRF glue for reinforcement of stumps. We recommend to perform the Bentall procedure, partial remodeling procedure, or valve-sparing aortic root replacement for reconstruction of the aortic root and arch replacement for repair of the aortic arch.

Catalytic asymmetric conjugate addition of thiols to α,ß-unsaturated thioamides: expeditious access to enantioenriched 1,5-benzothiazepines.

Softly does it: The title reaction proceeded under proton transfer conditions with a catalyst prepared from commercially available reagents to afford the desired product in high enantioselectivity. The reaction was compatible with a free amino group, thus allowing for expeditious access to enantiomerically enriched 1,5-benzothiazepines, which are important chemical entities in medicinal chemistry.

Intermediate as catalyst: catalytic asymmetric conjugate addition of nitroalkanes to α,ß-unsaturated thioamides.

Catalytic asymmetric conjugate addition of nitroalkanes to α,ß-unsaturated thioamides is promoted by a mesitylcopper/(R)-DTBM-Segphos precatalyst, affording γ-nitrothioamides in moderate to high syn-selectivity and excellent enantioselectivity. The intermediate Cu-thioamide enolate functions as a soft Lewis acid/hard Brønsted base cooperative catalyst to drive the catalytic cycle efficiently under proton transfer conditions.