Pharmacokinetic / pharmacodynamic relationships of liposomal amphotericin B and miltefosine in experimental visceral leishmaniasis.

BACKGROUND: There is a continued need to develop effective and safe treatments for visceral leishmaniasis (VL). Preclinical studies on pharmacokinetics and pharmacodynamics of anti-infective agents, such as anti-bacterials and anti-fungals, have provided valuable information in the development and dosing of these agents. The aim of this study was to characterise the pharmacokinetic and pharmacodynamic properties of the anti-leishmanial drugs AmBisome and miltefosine in a preclinical disease model of VL. METHODOLOGY / PRINCIPAL FINDINGS: BALB/c mice were infected with L. donovani (MHOM/ET/67/HU3) amastigotes. Groups of mice were treated with miltefosine (orally, multi-dose regimen) or AmBisome (intravenously, single dose regimen) or left untreated as control groups. At set time points groups of mice were killed and plasma, livers and spleens harvested. For pharmacodynamics the hepatic parasite burden was determined microscopically from tissue impression smears. For pharmacokinetics drug concentrations were measured in plasma and whole tissue homogenates by LC-MS. Unbound drug concentrations were determined by rapid equilibrium dialysis. Doses exerting maximum anti-leishmanial effects were 40 mg/kg for AmBisome and 150 mg/kg (cumulatively) for miltefosine. AmBisome displayed a wider therapeutic range than miltefosine. Dose fractionation at a total dose of 2.5 mg/kg pointed towards concentration-dependent anti-leishmanial activity of AmBisome, favouring the administration of large doses infrequently. Protein binding was >99% for miltefosine and amphotericin B in plasma and tissue homogenates. CONCLUSION / SIGNIFICANCE: Using a PK/PD approach we propose optimal dosing strategies for AmBisome. Additionally, we describe pharmacokinetic and pharmacodynamic properties of miltefosine and compare our findings in a preclinical disease model to available knowledge from studies in humans. This approach also presents a strategy for improved use of animal models in the drug development process for VL

Effectiveness of a Virtual Exercise Program During COVID-19 Confinement on Blood Pressure Control in Healthy Pregnant Women

Background: The situation caused by COVID-19 has led to movement restrictions for the majority of the population due to the confinement established by the health authorities. This new situation has changed people’s habits and significantly affected the pregnant population. Decreased exercise and increased psychophysical stress are associated with excessive weight gain, diabetes, and gestational cardiovascular complications that affect the mother, fetus, and newborn. Recent research shows that the dynamics of maternal blood pressure is one of the most important control factors during pregnancy. Thus, prevention of these type of pathologies through interventions without maternal-fetal risks is important. Objectives: To examine the influence of a virtual exercise program on maternal blood pressure during pregnancy. Materials and Methods: A randomized clinical trial design was used (NCT04563065). Data from 72 pregnant women without obstetric contraindications under confinement conditions in the Madrid area were collected. Women were randomly assigned to the intervention (IG) or control group (CG). They previously signed informed consent forms. A moderate exercise program was performed as an intervention from 8–10 to 38–39 weeks of pregnancy. Systolic (SBP) and diastolic (DBP) maternal blood pressure were measured during the first, second and third trimesters of pregnancy, as well as before and immediately after delivery in both study groups. Results: No differences in systolic and diastolic blood pressure during the first, second and third trimesters were found between groups. Significant differences in SBP were found immediately before delivery (IG = 119.83 ± 10.16 vs. CG = 125.6 ± 10.91; p = 0.047) and immediately after delivery (IG = 115.00 ± 11.18 vs. CG = 122.24 ± 15.71; p = 0.045). Conclusions: Results show lower SBP values for the IG during delivery than CG. A virtual exercise program throughout pregnancy during COVID-19 confinement can help to control systolic blood pressure before and immediately after delivery in healthy pregnant women