Daptomycin-containing regimens for treatment of Gram-positive endocarditis

Purpose: Infective endocarditis (IE) is a severe infection, and a leading cause of mortality and morbidity. Due to its favourable microbiological and pharmacological characteristics, daptomycin is routinely used in clinical practice for treating IE. Methods: A prospective study was conducted at a large tertiary-care hospital in Italy over an 8-year period (January 2010-January 2018) on all patients with native-valve endocarditis (NVE) or prosthetic-valve endocarditis (PVE) caused by Gram-positive bacteria. Patients with NVE and PVE treated with regimens that included daptomycin at different dosages (daptomycin-containing regimens, DCR) were compared with those treated with non-DCR. Primary endpoints of the study were 30-day mortality and clinical treatment failure. Results: During the study period, 327 patients with Gram-positive NVE (n = 224, 68.8%) or PVE (n = 103, 31.2%) were analysed. Eighty-four (37.5%) NVE patients were treated with daptomycin, alone (59.9%) or with other antimicrobials. Most PVE patients (n = 61, 58%) were treated with a DCR, which always consisted of daptomycin plus other drugs. Among PVE patients, treatment with a DCR was associated with lower 30-day mortality than treatment with a non-DCR (6.5% vs. 38%, P < 0.001). Among NVE patients treated with DCRs, risk factors for 30-day mortality were streptococcal infections, persistent bacteraemia, and standard-dose (4-6 mg/kg) rather than high-dose daptomycin therapy. Overall, surgical treatment of IE and DCR were associated with clinical success and 30-day survival. Conclusions: Compared with non-DCRs, using single-drug or multiple-drug DCRs is associated with lower 30-day mortality in PVE, but with higher 30-day mortality in NVE at approved doses and in a subgroup of streptococcal IE. (C) 2019 Elsevier B.V. and International Society of Chemotherapy. All rights reserved

Should High-dose Daptomycin be an Alternative Treatment Regimen for Enterococcal Endocarditis?

Introduction Previous series on the use of daptomycin in enterococcal infective endocarditis (EIE) have shown various outcomes, including higher mortality rates. We analyzed the effectiveness of high-dose daptomycin for the treatment of EIE. Methods We performed a prospective study from 2010 to 2018 in a referral center in patients with native (NVE) and prosthetic valve endocarditis (PVE) due to Enterococcus spp. The standard high-dose daptomycin at our institution is 10-12 mg/kg/day (CLCr > 30 ml/min). We compared the efficacy of a daptomycin-based regimen (DBR) versus daptomycin-sparing regimen (DSR) and daptomycin monotherapy versus combination therapy. Primary endpoints of the study were evaluation of risk factors associated with 30-day mortality and failure at end of therapy. Results We collected 43 EIE cases; 29 were NVE (67.4%). Overall, 16 (37.2%) were treated with DBR, mainly with combination regimens (11, 68.7%), in the majority of cases in association with ss-lactam (7, 43.7%). The mean administered dose of daptomycin was 10.125 mg/kg/day (range 8-12 mg/kg/day). Overall, patients treated with DBR compared with patients treated with DSR had no higher mortality rates and/or failure at end of therapy (6.2% vs. 22. 2%; P 0.41 and MICs 0.25-2 mg/l, 6.2% vs. 3.7%; P 1.0). In the sub-group of patients with NVE and PVE treated with DBR and DSR, no difference was found regarding the primary endpoints on the single or combined use of daptomycin. Conclusion Our findings suggest that high-dose daptomycin might be used as an alternative treatment regimen in EIE

Compaction, compression and drug release properties of diclofenac sodium and ibuprofen pellets comprising xanthan gum as a sustained release agent

Compaction and compression of xanthan gum pellets were evaluated and drug release from tablets made of pellets was characterised. Two types of pellets were prepared by extrusion-spheronisation. Formulations included xanthan gum, at 16% (w/w), diclofenac sodium or ibuprofen, at 10% (w/w), among other excipients. An amount of 500 mg of pellets fraction 1000-1400 [mu]m were compacted in a single punch press at maximum punch pressure of 125 MPa using flat-faced punches (diameter of 1.00 cm). Physical properties of pellets and tablets were analysed. Laser profilometry analysis and scanning electron microscopy of the upper surface and the surface of fracture of tablets revealed that particles remained as coherent individual units after compression process. Pellets were flatted in the same direction of the applied stress evidencing a lost of the original curvature of the spherical unit. Pellets showed close compressibility degrees (49.9% for pellets comprising diclofenac sodium and 48.5% for pellets comprising ibuprofen). Xanthan gum pellets comprising diclofenac sodium experienced a reduction of 65.5% of their original sphericity while those comprising ibuprofen lost 49.6% of the original porosity. Permanent deformation and densification were the relevant mechanisms of compression. Fragmentation was regarded as non-existent. The release of the model drug from both type of tablets revealed different behaviours. Tablets made of pellets comprising ibuprofen released the model drug in a bimodal fashion and the release behaviour was characterised as Case II transport mechanism (release exponent of 0.93). On the other hand, the release behaviour of diclofenac sodium from tablets made of pellets was anomalous (release exponent of 0.70). For the latter case, drug diffusion and erosion were competing mechanisms of drug release.http://www.sciencedirect.com/science/article/B6T7W-4FR3ND1-1/1/7bebf72d7c381f0ef545c3c20689017

Optimization of bilayer floating tablet containing metoprolol tartrate as a model drug for gastric retention

The purpose of the present study was to develop an optimized gastric floating drug delivery system (GFDDS) containing metoprolol tartrate (MT) as a model drug by the optimization technique. A 23 factorial design was employed in formulating the GFDDS with total polymer content-to-drug ratio (X1), polymer-to-polymer ratio (X2), and different viscosity grades of hydroxypropyl methyl cellulose (HPMC) (X3) as independent variables. Four dependent variables were considered: percentage of MT release at 8 hours, T50%, diffusion coefficient, and floating time. The main effect and interaction terms were quantitatively evaluated using a mathematical model. The results indicate that X1 and X2 significantly affected the floating time and release properties, but the effect of different viscosity grades of HPMC (K4M and K10M) was nonsignificant. Regression analysis and numerical optimization were performed to identify the best formulation. Fickian release transport was confirmed as the release mechanism from the optimized formulation. The predicted values agreed well with the experimental values, and the results demonstrate the feasibility of the model in the development of GFDDS