Abstract
The long-acting antiretroviral cabotegravir and rilpivirine combination has just received FDA, EMA and Health Canada approval. This novel drug delivery approach is about to revolutionize the ...therapy of people living with HIV, decreasing the 365 daily pill burden to only six intramuscular injections per year. In addition, islatravir, a first-in-class nucleoside reverse transcriptase translocation inhibitor, is intended to be formulated as an implant with a dosing interval of 1 year or more. At present, long-acting antiretroviral therapies (LA-ARTs) are given at fixed standard doses, irrespectively of the patient’s weight and BMI, and without consideration for host genetic and non-genetic factors likely influencing their systemic disposition. Despite a few remaining challenges related to administration (e.g. pain, dedicated medical procedure), the development and implementation of LA-ARTs can overcome long-term adherence issues by improving patients’ privacy and reducing social stigma associated with the daily oral intake of anti-HIV treatments. Yet, the current ‘one-size-fits-all’ approach does not account for the recognized significant inter-individual variability in LA-ART pharmacokinetics. Therapeutic drug monitoring (TDM), an important tool for precision medicine, may provide physicians with valuable information on actual drug exposure in patients, contributing to improve their management in real life. The present review aims to update the current state of knowledge on these novel promising LA-ARTs and discusses their implications, particularly from a clinical pharmacokinetics perspective, for the future management and prevention of HIV infection, issues of ongoing importance in the absence of curative treatment or an effective vaccine.
Cytokine hemoadsorption might be beneficial in patients with sepsis. However, its effect on anti-infective agents' disposition remains largely unknown. We sought to determine the influence of ...hemoadsorption on the pharmacokinetics of common anti-infective agents. This is an interventional experimental study, conducted in 24 healthy pigs. Animals were randomly allocated to either hemoadsorption (cases) or sham extracorporeal circuit (controls) and to drug combinations (3 cases and 3 controls for each combination). Hemoadsorption was performed with CytoSorb (CytoSorbents Corporation, USA). We evaluated 17 drugs (clindamycin, fluconazole, linezolid, meropenem, piperacillin, anidulafungin, ganciclovir, clarithromycin, posaconazole, teicoplanin, tobramycin, ceftriaxone, ciprofloxacin, metronidazole, liposomal amphotericin B, flucloxacillin and cefepime). Repeated blood sampling from the extracorporeal circulation (adsorber inlet/outlet, sham circuit) was performed over six hours following administration. Total clearance and adsorber-specific clearance were computed. Hemoadsorption was associated with increased clearance of all study drugs, except ganciclovir. Its impact on total body clearance was considered as moderate for fluconazole (282%) and linezolid (115%), mild for liposomal amphotericin B (75%), posaconazole (32%) and teicoplanine (31%) and negligible for all other drugs. Hemoadsorber clearance declined over time, with even delayed desorption for beta-lactams. It was moderately correlated with drug's lipophilicity (p = 0.01; r
= 0.43). Hemoadsorption with CytoSorb appears to increase to a clinically significant extent the clearance of five among 17 tested anti-infectives. Studies in human patients are required to confirm the need for dosage adjustment of these agents.
In order to improve the efficacy and safety of treatments, drug dosage needs to be adjusted to the actual needs of each patient in a truly personalized medicine approach. Key for widespread dosage ...adjustment is the availability of point-of-care devices able to measure plasma drug concentration in a simple, automated, and cost-effective fashion. In the present work, we introduce and test a portable, palm-sized transmission-localized surface plasmon resonance (T-LSPR) setup, comprised of off-the-shelf components and coupled with DNA-based aptamers specific to the antibiotic tobramycin (467 Da). The core of the T-LSPR setup are aptamer-functionalized gold nanoislands (NIs) deposited on a glass slide covered with fluorine-doped tin oxide (FTO), which acts as a biosensor. The gold NIs exhibit localized plasmon resonance in the visible range matching the sensitivity of the complementary metal oxide semiconductor (CMOS) image sensor employed as a light detector. The combination of gold NIs on the FTO substrate, causing NIs size and pattern irregularity, might reduce the overall sensitivity but confers extremely high stability in high-ionic solutions, allowing it to withstand numerous regeneration cycles without sensing losses. With this rather simple T-LSPR setup, we show real-time label-free detection of tobramycin in buffer, measuring concentrations down to 0.5 μM. We determined an affinity constant of the aptamer–tobramycin pair consistent with the value obtained using a commercial propagating-wave based SPR. Moreover, our label-free system can detect tobramycin in filtered undiluted blood serum, measuring concentrations down to 10 μM with a theoretical detection limit of 3.4 μM. While the association signal of tobramycin onto the aptamer is masked by the serum injection, the quantification of the captured tobramycin is possible during the dissociation phase and leads to a linear calibration curve for the concentrations over the tested range (10–80 μM). The plasmon shift following surface binding is calculated in terms of both plasmon peak location and hue, with the latter allowing faster data elaboration and real-time display of the results. The presented T-LSPR system shows for the first time label-free direct detection and quantification of a small molecule in the complex matrix of filtered undiluted blood serum. Its uncomplicated construction and compact size, together with the remarkable performances, represent a leap forward toward effective point-of-care devices for therapeutic drug concentration monitoring.
Complementary medicine (CM) is used by one third to one half of cancer patients throughout the world. The objective of this study was to describe the prevalence of CM use and the potential for ...interactions with cancer treatments in an academic oncology centre. A cross-sectional study was conducted among patients undergoing current cancer treatment. Among 132 included patients, 56% had used CM since their cancer diagnosis and 45% were using CM during cancer treatment at the time of the survey. The main CM used were green tea (35%), herbal tea (35%), homeopathy (27%), dietary supplements (27%), and herbal medicines (27%). A small majority of patients (58%) spontaneously mentioned the use of CM to their oncologist. Of 42 identified combinations of concomitant use of biologically based CM and anticancer agents among the study patients, the potential for pharmacokinetic interactions of clinical relevance was not expected in 17 combinations (40%), hypothetical and deemed unlikely in 23 (55%), and of probable low clinical relevance in 2 (5%). Considering the high prevalence of CM use, active enquiries should be made by healthcare professionals to detect symptoms that may relate to CM tolerance and effects or that suggest interactions between CM and cancer treatments.
Pharmacometric methods have hugely benefited from progress in analytical and computer sciences during the past decades, and play nowadays a central role in the clinical development of new medicinal ...drugs. It is time that these methods translate into patient care through therapeutic drug monitoring (TDM), due to become a mainstay of precision medicine no less than genomic approaches to control variability in drug response and improve the efficacy and safety of treatments. In this review, we make the case for structuring TDM development along five generic questions: 1) Is the concerned drug a candidate to TDM? 2) What is the normal range for the drug's concentration? 3) What is the therapeutic target for the drug's concentration? 4) How to adjust the dosage of the drug to drive concentrations close to target? 5) Does evidence support the usefulness of TDM for this drug? We exemplify this approach through an overview of our development of the TDM of imatinib, the very first targeted anticancer agent. We express our position that a similar story shall apply to other drugs in this class, as well as to a wide range of treatments critical for the control of various life-threatening conditions. Despite hurdles that still jeopardize progress in TDM, there is no doubt that upcoming technological advances will shape and foster many innovative therapeutic monitoring methods.
The benzothiazinone lead compound, BTZ043, kills Mycobacterium tuberculosis by inhibiting the essential flavo‐enzyme DprE1, decaprenylphosphoryl‐beta‐D‐ribose 2‐epimerase. Here, we synthesized a new ...series of piperazine‐containing benzothiazinones (PBTZ) and show that, like BTZ043, the preclinical candidate PBTZ169 binds covalently to DprE1. The crystal structure of the DprE1‐PBTZ169 complex reveals formation of a semimercaptal adduct with Cys387 in the active site and explains the irreversible inactivation of the enzyme. Compared to BTZ043, PBTZ169 has improved potency, safety and efficacy in zebrafish and mouse models of tuberculosis (TB). When combined with other TB drugs, PBTZ169 showed additive activity against M. tuberculosis in vitro except with bedaquiline (BDQ) where synergy was observed. A new regimen comprising PBTZ169, BDQ and pyrazinamide was found to be more efficacious than the standard three drug treatment in a murine model of chronic disease. PBTZ169 is thus an attractive drug candidate to treat TB in humans.
Synopsis
Tuberculosis (TB) drug resistance is still spreading worldwide, emphasizing the need for new efficient drug combinations. PBTZ169 is here presented as an optimized, potent and synergistic preclinical drug candidate for the treatment of TB in humans.
The development of a new candidate drug, PBTZ169, for the treatment of tuberculosis is described.
Atomic level understanding of the action of PBTZ169 against its target DprE1 is available.
A new PBTZ169 combination therapy has been tested in a murine model and shown to be superior to the existing standard of care.
Tuberculosis (TB) drug resistance is still spreading worldwide, emphasizing the need for new efficient drug combinations. PBTZ169 is here presented as an optimized, potent and synergistic preclinical drug candidate for the treatment of TB in humans.
Biomarker-guided treatments are needed in psychiatry, and previous data suggest oxidative stress may be a target in schizophrenia. A previous add-on trial with the antioxidant N-acetylcysteine (NAC) ...led to negative symptom reductions in chronic patients. We aim to study NAC's impact on symptoms and neurocognition in early psychosis (EP) and to explore whether glutathione (GSH)/redox markers could represent valid biomarkers to guide treatment. In a double-blind, randomized, placebo-controlled trial in 63 EP patients, we assessed the effect of NAC supplementation (2700 mg/day, 6 months) on PANSS, neurocognition, and redox markers (brain GSH GSHmPFC, blood cells GSH levels GSHBC, GSH peroxidase activity GPxBC). No changes in negative or positive symptoms or functional outcome were observed with NAC, but significant improvements were found in favor of NAC on neurocognition (processing speed). NAC also led to increases of GSHmPFC by 23% (P = .005) and GSHBC by 19% (P = .05). In patients with high-baseline GPxBC compared to low-baseline GPxBC, subgroup explorations revealed a link between changes of positive symptoms and changes of redox status with NAC. In conclusion, NAC supplementation in a limited sample of EP patients did not improve negative symptoms, which were at modest baseline levels. However, NAC led to some neurocognitive improvements and an increase in brain GSH levels, indicating good target engagement. Blood GPx activity, a redox peripheral index associated with brain GSH levels, could help identify a subgroup of patients who improve their positive symptoms with NAC. Thus, future trials with antioxidants in EP should consider biomarker-guided treatment.
OBJECTIVE:To investigate pregnancy outcomes following maternal use of pregabalin.
METHODS:This multicenter, observational prospective cohort study compared pregnancy outcomes in women exposed to ...pregabalin with those of matched controls (not exposed to any medications known to be teratogenic or to any antiepileptic drugs). Teratology Information Services systematically collected data between 2004 and 2013.
RESULTS:Data were collected from 164 exposed pregnancies and 656 controls. A significantly higher major birth defect rate in the pregabalin group was observed after exclusion of chromosomal aberration syndromes, and when cases with exposure during first trimester of pregnancy were analyzed separately (7/116 6.0% vs 12/580 2.1%; odds ratio 3.0, 95% confidence interval 1.2–7.9, p = 0.03). The rate of live births was lower in the pregabalin group (71.9% vs 85.2%, p < 0.001), primarily due to a higher rate of both elective (9.8% vs 5.0%, p = 0.02) and medically indicated (5.5% vs 1.8%, p = 0.008) pregnancy terminations. In the Cox proportional cause specific hazards model, pregabalin exposure was not associated with a significantly higher risk of spontaneous abortion.
CONCLUSIONS:This study demonstrated a signal for increased risk of major birth defects after first trimester exposure to pregabalin. However, several limitations such as the small sample size, differences across groups in maternal conditions, and concomitant medication exposure exclude definitive conclusions, so these results call for confirmation through independent studies.
Objective
Therapeutic drug monitoring (TDM) of antiepileptic drugs (AEDs) is widely established for older generation AEDs, whereas there is limited evidence about newer AEDs. Our aim is to assess the ...benefit of TDM of newer generation AEDs in epilepsy.
Methods
We performed a randomized, controlled trial comparing systematic with rescue TDM of lamotrigine, levetiracetam, oxcarbazepine, topiramate, brivaracetam, zonisamide, or pregabalin. Participants were adults with epilepsy, in whom treatment with newer generation AEDs was initiated or needed adjustment. In the systematic TDM arm, AED plasma levels were available at each appointment, whereas in the rescue TDM arm, levels were known only if a study endpoint was reached (inefficacy or adverse events). The primary outcome was the proportion of participants followed 1 year without reaching one of the predefined endpoints.
Results
A total of 151 participants were enrolled; global retention in the study was similar in both arms (56% overall, 58% in the systematic, and 53% in the rescue TDM arm, p = 0.6, Cox regression). There was no difference in terms of outcome regarding treatment efficacy or tolerability. Partial adherence of clinicians to TDM (adjusting or not AED dosage based on blood levels) did not explain this lack of benefit.
Interpretation
This study provides class A evidence that systematic drug level monitoring of newer generation AEDs does not bring tangible benefits in the management of patients with epilepsy. Poor correlation between clinical effects and drug levels likely accounts for this finding. However, TDM is useful in several situations, such as pregnancy, as well as when there are compliance issues. ANN NEUROL 2020;87:22–29
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