Proactive therapeutic monitoring of dalbavancin concentrations in the long-term management of chronic osteoarticular/periprosthetic joint infections.

Here, we describe the use of proactive therapeutic drug monitoring (TDM) to individualize the optimal timing of drug injections in 16 adult patients with chronic osteoarticular infections receiving a median of 7 injections of dalbavancin (up to 12 injections in 15 months). Dalbavancin injections were repeated at medians of 39-47 days, with infusion intervals ranging from 26 to 69 days. TDM can facilitates a precise, targeted use of dalbavancin for infections requiring prolonged treatments.

Rilpivirine and cabotegravir trough concentrations in people with HIV on long-term treatment with long-acting injectable antiretrovirals.

OBJECTIVE: Large inter-individual variability in the pharmacokinetics of rilpivirine and cabotegravir has been reported in the first weeks after starting long-acting injectable (LAI) therapy. Here, we assessed the distribution of rilpivirine and cabotegravir trough concentrations in people with HIV (PWH) on long-term LAI treatment. METHODS: Adult PWH treated with LAI for at least 32 weeks with an assessment of drug plasma trough concentrations were considered. The proportion of rilpivirine and cabotegravir plasma trough concentrations below four-times the protein-adjusted concentrations required for 90% inhibition of viral replication (4×PA-IC90) was estimated. RESULTS: Sixty-seven PWH were identified. LAI treatment duration was 216 ±â€Š80 weeks (range 32-320 weeks). Cabotegravir concentrations were associated with lower inter-individual variability compared with rilpivirine (45% versus 84%; P < 0.05). No differences were found in rilpivirine (160 ±â€Š118 versus 189 ±â€Š81 ng/mL; P = 0.430) and cabotegravir (1758 ±â€Š807 versus 1969 ±â€Š802 ng/mL; P = 0.416) trough concentrations in males (n = 55) versus females (n = 12). A non-significant trend for lower cabotegravir concentrations was found in PWH with a body mass index >30 kg/m2 (n = 9) versus non-obese participants (1916 ±â€Š905 versus 1606 ±â€Š576 ng/mL; P = 0.131). Three out of the 67 PWH had at least one drug concentration <4×PA-IC90: 100% of PWH had undetectable HIV viral load. CONCLUSIONS: At steady state, optimal systemic exposure of cabotegravir and rilpivirine was found in most PWH; cabotegravir trough concentrations were associated with lower inter-individual variability compared with rilpivirine. The study was not powered to assess the contribution of sex and/or body weight on LAI exposure due to the small number of females and obese PWH included.

Effect of Carbamazepine on Darunavir Trough Concentrations: When the Dose Can Make the Difference-A Case Study.

BACKGROUND: Carbamazepine (CBZ) is an antiseizure medication known to induce the expression of cytochrome P4503A metabolic enzymes. Here, we describe a man living with HIV who underwent several changes in the daily dose of CBZ, which resulted in different induction effects on darunavir trough concentrations. METHODS: A 59-year-old man with HIV, successfully undergoing maintenance antiretroviral treatment with darunavir/cobicistat once daily (combined with raltegravir), was prescribed CBZ for recurrent trigeminal neuralgia. Over subsequent months, the patient underwent various changes in the doses (from 200 to 800 mg/d) and trough concentrations (from 3.6 to 18.0 mg/L) of CBZ, guided by clinical response to trigeminal neuralgia. RESULTS: A highly significant inverse association was observed between darunavir trough concentration and both CBZ dose or trough concentration (coefficient of determination >0.75, P < 0.0001). Ultimately, the darunavir dose was increased to 600 mg twice daily with ritonavir and dolutegravir to ensure optimal antiretroviral coverage, anticipating potential further uptitration of CBZ doses. CONCLUSIONS: The impact of CBZ on boosted darunavir exposure seemed to be dose- and concentration-dependent. The management of such drug-drug interactions in daily practice was facilitated through therapeutic drug monitoring. This case underscores the importance of a multidisciplinary approach that incorporates both antiretroviral and nonantiretroviral comedications contributing to the optimal management of polypharmacy in individuals living with HIV.

Management of the Drug-Drug Interactions Between Valproic Acid and Dolutegravir-A Case Study.

OBJECTIVE: Preliminary evidence shows that concomitant administration of valproic acid can reduce the exposure to dolutegravir with limited clinical impacts. Here, we describe a male living with HIV who experienced a drastic reduction in dolutegravir trough concentrations a few weeks after starting valproic acid treatment as identified by therapeutic drug monitoring. Concomitantly, pharmacists recommended a supplementation of magnesium to improve insomnia. CASE REPORT: A 62-year-old man with HIV on antiretroviral therapy with dolutegravir and lamivudine recently added valproic acid to clonazepam and sertraline to treat severe sleep disturbances. An 84% reduction in dolutegravir trough concentrations was observed compared with the previous outpatient visit (418 versus 2714 ng/mL), with values close to the minimum effective drug concentration (300 ng/mL). Considering this, we strongly discourage the use of magnesium. CONCLUSIONS: We are confident that our findings can contribute to a better understanding of the clinical problems that infectious disease physicians encounter in their daily management of people with HIV and how therapeutic drug monitoring may add value in this context. This case also highlights the importance of multidisciplinary services for the optimal management of polypharmacy in people with HIV.

Adverse events during intravenous fosfomycin therapy in a real-life scenario. Risk factors and the potential role of therapeutic drug monitoring.

BACKGROUND: Intravenous fosfomycin (IVFOF) is gaining interest in severe infections. Its use may be limited by adverse events (AEs). Little experience exists on IVFOF therapeutic drug monitoring (TDM) in real-life setting. PATIENTS AND METHODS: Retrospective study of patients receiving IVFOF for > 48 h at Policlinico Hospital (Milan, Italy) from 01/01/2019 to 01/01/2023. AEs associated to IVFOF graded CTCAE ≥ II were considered. Demographic and clinical risk factors for IVFOF-related AEs were analysed with simple and multivariable regression models. The determination of IVFOF TDM was made by a rapid ultraperformance liquid chromatography mass spectrometry method (LC-MS/MS) on plasma samples. The performance of TDM (trough levels (Cmin) in intermittent infusion, steady state levels (Css) in continuous infusion) in predicting AEs ≤ 5 days after its assessment was evaluated. RESULTS: Two hundred and twenty-four patients were included. At IVFOF initiation, 81/224 (36.2%) patients were in ICU and 35/224 (15.7%) had septic shock. The most frequent infection site was the low respiratory tract (124/224, 55.4%). Ninety-five patients (42.4%) experienced ≥ 1AEs, with median time of 4.0 (2.0-7.0) days from IVFOF initiation. Hypernatremia was the most frequent AE (53/224, 23.7%). Therapy discontinuation due to AEs occurred in 38/224 (17.0%). ICU setting, low respiratory tract infections and septic shock resulted associated with AEs (RRadjusted 1.59 (95%CI:1.09-2.31), 1.46 (95%CI:1.03-2.07) and 1.73 (95%CI:1.27-2.37), respectively), while IVFOF daily dose did not. Of the 68 patients undergone IVFOF TDM, TDM values predicted overall AEs and hypernatremia with AUROC of 0.65 (95%CI:0.44-0.86) and 0.91 (95%CI:0.79-1.0) respectively for Cmin, 0.67 (95%CI:0.39-0.95) and 0.76 (95%CI:0.52-1.0) respectively for Css. CONCLUSIONS: We provided real world data on the use of IVFOF-based regimens and associated AEs. IVFOF TDM deserves further research as it may represent a valid tool to predict AEs. KEY POINTS: Real world data on intravenous fosfomycin for severe bacterial infections. AEs occurred in over 40% (therapy discontinuation in 17%) and were related to baseline clinical severity but not to fosfomycin dose. TDM showed promising results in predicting AEs.

Pilot, open-label, randomized controlled clinical trial evaluating 4 oral hygiene regimens using a manual toothbrush, toothpaste, and mouthwash.

In this prospective pilot study, 84 patients with a history of poor oral hygiene were enrolled in an open-label, interventional, randomized controlled clinical trial. The aim was to provide preliminary clinical data on a new line of oral hygiene products containing a prebiotic and a paraprobiotic based on Lactobacillus plantarum. The recruitment rate and patient satisfaction were analyzed to estimate resources for the future primary study, and descriptive data on rebalancing of the oral microbiota were collected. The population was divided into 5 groups based on the products assigned to the patients: 1, delicate mint toothpaste (n = 20); 2, mint toothpaste (n = 12); 3, mint mouthwash (n = 20); 4, delicate mint toothpaste, mint mouthwash, and an antimicrobial toothbrush (n = 20); and 5, continued use of their usual oral care products and routine (control group; n = 12). The study duration was 28 days. All patients tolerated the products well, and there were no adverse events. The recruitment capability and procedures allowed for a realistic estimation for the future main trial. The products did not cause any changes in tooth color. The participants in group 4, who completed the treatment consisting of delicate mint toothpaste, mint mouthwash, and an antimicrobial toothbrush, reported the greatest reduction in gingival sensitivity (P ≤ 0.000; Wilcoxon signed rank test). Analysis with the Wilcoxon signed rank test revealed that all products induced a statistically significant decrease in plaque (P ≤ 0.002) and a reduction in gingival sensitivity (delicate mint toothpaste, P ≤ 0.005; mint toothpaste, P ≤ 0.015; and mint mouthwash, P ≤ 0.015). All products were effective in stabilizing the oral microbiota. The tested products showed an optimal safety profile and a statistically significant efficacy in reducing gingival sensitivity and plaque. They also stabilized the biodiversity of the oral microbiota, making it less susceptible to microbial fluctuations than the control group. Trial registration: ClinicalTrials.gov (NCT05999175).

Therapeutic drug monitoring of antiretroviral therapy: current progresses and future directions.

INTRODUCTION: The treatment of HIV infection has been revolutionized in recent years thanks to the advent of dual antiretroviral regimens, administered orally or as long-acting injectable formulations. Here, we provide an update on the usefulness of therapeutic drug monitoring (TDM) of antiretroviral drugs to optimize the management of people with HIV (PWH) in the current scenario. AREAS COVERED: A MEDLINE PubMed search for articles published between January 2014 and January 2024 was completed matching the terms HIV, antiretrovirals and TDM. Moreover, additional studies were identified from the reference list of retrieved articles. EXPERT OPINION: Available antiretroviral treatments achieve a response rate of 90%-95%, making the routine TDM of antiretroviral drugs of limited clinical value. However, there are still some important applications of TDM in selected clinical conditions, such as assessing patient compliance or suspected drug-drug interactions (DDIs). Indeed, we are increasingly having to deal with polypharmacy and DDIs in the context of an aging patient with comorbidities that may potentially alter the pharmacokinetics of antiretroviral drugs. Finally, the role of pharmacogenetics, which is closely related to TDM, in influencing both the disposition of antiretrovirals and the course of DDIs should also be considered.

No effects of nirmatrelvir/ritonavir on darunavir plasma trough concentrations: a case report.

COVID-19 may be associated with worst outcomes in people living with HIV compared with HIV-negative patients. Nirmatrelvir/ritonavir can be safely co-administered with all the HIV antiretroviral drugs, without considering dose adjustment. However, no studies have formally investigated the effect of a double booster (ritonavir plus cobicistat) regimen on darunavir concentrations. We presented a case describing the lack of effects of adding nirmatrelvir/ritonavir on darunavir plasma trough concentrations in a patient with HIV already on treatment with a booster-based antiretroviral regimen. We believe this could be a reassuring message for physicians, allowing them to prevent unnecessary denial of COVID-19 treatment or inappropriate discontinuation of co-medications in patients with HIV.

Optimizing Antibiotic Therapy for Intravenous Drug Users: A Narrative Review Unraveling Pharmacokinetics/Pharmacodynamics Challenges.

Intravenous drug users (IVDUs) face heightened susceptibility to life-threatening gram-positive bacterial infections, particularly methicillin-resistant Staphylococcus aureus (MRSA). While the standard antibiotic dosing strategies for special patients, such as obese or critically ill individuals, are known to be inadequate, raising concerns about treatment efficacy, a similar sort of understanding has not been assessed for IVDUs yet. With this in mind, this review examines the pharmacokinetic/pharmacodynamic characteristics of antibiotics commonly used against gram-positive bacteria in IVDUs. Focusing on daptomycin, vancomycin, teicoplanin, aminoglycosides, and the novel lipoglycopeptide dalbavancin, the study reveals significant pharmacokinetic variations in IVDUs, suggesting the need for personalized dosing. Concomitant opioid substitution therapy and other factors, such as malnutrition, contribute to altered pharmacokinetics/pharmacodynamics, emphasizing the importance of targeted therapeutic drug monitoring. Overall, our study calls for increased awareness among clinicians regarding the unique pharmacokinetic/pharmacodynamic challenges in IVDUs and advocates for tailored antibiotic dosing strategies to enhance treatment outcomes in this marginalized population.

Management of Polypharmacy and Potential Drug-Drug Interactions in Patients with Pulmonary Aspergillosis: A 2-Year Study of a Multidisciplinary Outpatient Clinic.

Pulmonary aspergillosis mainly affects elderly patients, patients with pulmonary complications, patients with hematological malignancies, organ transplant recipients, or critically ill patients. Co-morbidities may result in a high rate of polypharmacy and a high risk of potential drug-drug interaction (pDDI)-related antifungal azoles, which are perpetrators of several pharmacokinetic- and pharmacodynamic-driven pDDIs. Here, we report the results of the first 2-year study of an outpatient clinic focusing on the management of therapies in patients with pulmonary aspergillosis. All patients who underwent an outpatient visit from May 2021 to May 2023 were included in this retrospective analysis. A total of 34 patients who were given an azole as an antifungal treatment (53% voriconazole, 41% isavuconazole, and 6% itraconazole) were included. Overall, 172 pDDIs were identified and classified as red- (8%), orange- (74%), or yellow-flag (18%) combinations. We suggested handling polypharmacy in those patients using specific diagnostic and pharmacologic interventions. As expected, red-flag pDDIs involved mainly voriconazole as a perpetrator (71%). However, nearly 30% of red-flag pDDIs were not related to antifungal therapy. These findings highlight the importance of conducting an overall assessment of the pharmacologic burden and the key role played by a multidisciplinary team for the optimization of therapies in patients with pulmonary aspergillosis.

Different effects of the companion antiretroviral drugs on dolutegravir trough concentrations.

BACKGROUND: Dolutegravir is widely used in different dual and triple antiretroviral regimens. Here, we sought to investigate the effect of the companion antiretroviral drug(s) on dolutegravir plasma trough concentrations in persons with HIV, with a focus on dual regimens. METHODS: Dolutegravir concentrations collected from October 2015 to March 2023 ( n  = 900) were stratified according to the main antiretroviral classes (NRTIs, NNRTIs, protease inhibitors) and according to single drugs. Dolutegravir concentrations measured in persons with HIV concomitantly treated with lamivudine were considered as the reference group. RESULTS: Dolutegravir trough concentrations were significantly higher in persons with HIV given protease inhibitors compared with the reference [1886 (1036-2940) versus 1575 (1026-2226) ng/ml; P  = 0.004]. The highest dolutegravir concentrations were measured in persons with HIV concomitantly treated with unboosted atazanavir [2908 (2130-4135) ng/ml]. Conversely, co-administration of darunavir/ritonavir resulted in significantly lower dolutegravir exposure [909 (496-1397) ng/ml; P  = 0.002 versus reference]. Among NNRTIs, the higher dolutegravir concentrations were measured in presence of rilpivirine [2252 (1489-2686); P  < 0.001 versus reference]. CONCLUSION: Dolutegravir trough concentrations are differently affected by individual antiretroviral drugs, with some drug combinations (i.e. dolutegravir/darunavir/cobicistat, or dolutegravir/rilpivirine) providing significantly higher than expected dolutegravir exposure. Such combinations might be advantageous when there are concerns about dolutegravir plasma exposure or resistance.

Mismanagement of SARS-CoV-2 Infection Pre Hospitalisation during the Omicron Era: Antibiotics and Steroids Instead of Early Antivirals.

The aim of this study was to assess the prevalence of inappropriate treatment among hospitalised patients affected by SARS-CoV-2 infection before hospital admission during the Omicron era. This single-centre, retrospective observational study included all the patients hospitalised because of SARS-CoV-2 infection during three periods characterised by the Italian prevalence of an Omicron variant of concern: (1) January-May 2022 (BA.1-BA.2), (2) June-October 2022 (BA.5), and (3) November 2022-March 2023 (BQ.1-XBB). Inappropriate treatment was defined as pre-hospitalisation exposure to antibiotics and/or steroids in the absence of a documented bacterial infection or the need for steroid treatment of an underlying medical condition. A total of 931 subjects were hospitalised: 394 in period 1, 334 in period 2, and 203 in period 3. Of the 157 patients undergoing inappropriate treatment (16.9%), 142 (15.3%) received antibiotics and 52 (5.6%) steroids. The proportion of inappropriately treated patients significantly decreased over time, from 23.1% in period 1 to 11.7% in period 2 and 13.3% in period 3 (p < 0.001), and there was a parallel decrease in antibiotic (p < 0.001) and steroid treatment (p < 0.013). Only 13 subjects (1.4%) received early pre-hospitalisation treatment for SARS-CoV-2. A significant proportion of hospitalised COVID-19 patients were exposed to inappropriate treatment before hospital admission.

Therapeutic Drug Monitoring of Dalbavancin in Real Life: A Two-Year Experience.

Dalbavancin is a long-acting lipoglycopeptide that is registered for the treatment of acute bacterial skin and skin structure infections, and it is also increasingly used for infections that require prolonged antibiotic treatment. Here, we present the results from the first 2 years of a service set up in December 2021 for the therapeutic drug monitoring (TDM) of dalbavancin in clinical settings. In particular, we compared the trough concentration (Cmin) to maximum concentration (Cmax) in patients with osteoarticular infections receiving prolonged treatment with dalbavancin. Log-linear regression models were used to estimate the timing of dalbavancin administration with the goal of maintaining Cmin concentrations of >8 mg/L in the two TDM-based strategies. From December 2021 to November 2023, 366 TDMs of dalbavancin from 81 patients were performed. The Cmin and Cmax concentrations of dalbavancin ranged from 4.1 to 70.5 mg/L and from 74.9 to 995.6 mg/L, respectively. With log-linear regression models, we estimated that each injection should be administered every 42-48 days to maintain the Cmin concentrations. Out of the 81 patients, 37 received at least three doses of dalbavancin for the treatment of osteoarticular infections. Despite there being no significant differences in the days of dalbavancin treatment (130 ± 97 versus 106 ± 102 days), the patients in the Cmax-based TDM group received a significantly lower number of dalbavancin injections (5.2 ± 1.8 versus 7.3 ± 2.6 injections, p = 0.005), and they were administered over a longer period of time (40 ± 10 versus 29 ± 14 days, p = 0.013) than in the Cmin-based TDM group. In conclusion, Cmax-based TDM was associated with a significant reduction in the inter-individual variability of dalbavancin concentrations and lower drug dosing frequency than those of Cmin-based TDM. This approach could, therefore, favor a more rational and targeted use of dalbavancin in patients requiring prolonged treatment.