Expert Opinion on Drug Metabolism & Toxicology

Garzon, Simone; Laganà, Antonio Simone; Monastra, Giovanni

doi: 10.1080/17425255.2019.1651839pmid: 31382802

Background: D-chiro-inositol (DCI) and glucose transporter inhibitors may inhibit myo-inositol (MI) transporters, and the aim is to clinically evaluate their effect on MI absorption.Research design and methods: Fasting 18 healthy volunteers received orally 6000 mg MI, 6000 mg MI with 1000 mg DCI, and 6000 mg MI with SelectSIEVE® Apple PCQ and Sorbitol, Maltodextrin and Sucralose (PCQ-SMS), in three different phases with a washout period of 7 days. At each phase, blood samples were collected before administration, and every 60 minutes until 540 minutes after administration. MI plasma levels (μmol/L) were quantified by gas chromatography-mass spectrometry; maximum plasma concentration (Cmax), time to reach it (Tmax), and the area under the time-concentration curve of MI (AUC 0-540) were evaluated.Results: The Cmax of MI alone (Tmax = 180min) was 1.29-fold higher than those of MI with DCI (Tmax = 180min) (p < 0.001) and 1.69-fold higher than those of MI with PCQ-SMS (Tmax = 240min) (p < 0.001). The AUC 0-540 was reduced by 19.09% in MI plus DCI (p = 0.0118) and by 31.8% in MI plus PCQ-SMS (p < 0.001) as compared to MI alone.Conclusions: DCI, glucose transporter inhibitors and sugars, such as sorbitol and maltodextrin, seem to inhibit MI absorption, decreasing MI plasma concentration as compared to MI alone.

Kunnumakkara, Ajaikumar B.; Harsha, Choudhary; Banik, Kishore; Vikkurthi, Rajesh; Sailo, Bethsebie L.; Bordoloi, Devivasha; Gupta, Subash C.; Aggarwal, Bharat B.

doi: 10.1080/17425255.2019.1650914pmid: 31361978

Introduction: Since ancient times, turmeric has been used in several folklore remedies against various ailments. The principal component of turmeric is curcumin and its efficacy has been advocated in various in vitro, in vivo and clinical studies for different chronic diseases. However, some studies suggest that curcumin bioavailability is a major problem.Areas covered: This article discusses over 200 clinical studies with curcumin that have demonstrated the pronounced protective role of this compound against cardiovascular diseases, inflammatory diseases, metabolic diseases, neurological diseases, skin diseases, liver diseases, various types of cancer, etc. The review also describes the combination of curcumin with many natural and synthetic compounds as well as various formulations of curcumin that have shown efficacy in multiple clinical studies.Expert opinion: The therapeutic potential of curcumin, as demonstrated by clinical trials has overpowered the myth that poor bioavailability of curcumin poses a problem. Low curcumin bioavailability in certain studies has been addressed by using higher concentrations of curcumin within nontoxic limits. Moreover, curcumin, in combination with other compounds or as formulations, has shown enhanced bioavailability. Hence, bioavailability is not a problem in the curcumin-mediated treatment of chronic diseases. Therefore, this golden nutraceutical presents a safe, low-cost and effective treatment modality for different chronic diseases.

Allegaert, Karel; Flint, Robert; Smits, Anne

doi: 10.1080/17425255.2019.1655540pmid: 31402708

Introduction: Vancomycin is commonly administered to neonates, while observational data on therapeutic drug monitoring (TDM, trough levels) suggest that vancomycin exposure and dosage remain substandard.Area covered: Data on vancomycin pharmacokinetics (PK) and its covariates are abundant. Consequently, modeling is an obvious tool to improve targeted exposure, with a shift from TDM trough levels to area under the curve (AUC24h) targets, as in adults. Continuous administration appeared as a practice to facilitate AUC24h target attainment, while Bayesian model-supported targeting emerged as a novel tool. However, the AUC24h/MIC (minimal inhibitory concentration) target itself should consider neonate-specific aspects (bloodstream infections, coagulase-negative staphylococci, protein binding, underexplored causes of variability, like assays, preparation and administration inaccuracies, or missing covariates).Expert opinion: To improve targeted exposure in neonates, initial vancomycin prescription should be based on ‘a priori model-based individual dosing’ using validated dosing regimens, followed by further tailoring by dosing optimization applying Bayesian estimation-assisted TDM. Future research should focus on the feasibility to integrate these tools (individualized dosing, Bayesian models) in clinical practice, and to perform PK/PD studies in the relevant animal models and human neonatal setting (coagulase-negative staphylococci, bloodstream infections).

Miscio, Giuseppe; Paroni, Giulia; Bisceglia, Paola; Gravina, Carolina; Urbano, Maria; Lozupone, Madia; Piccininni, Carla; Prisciandaro, Michele; Ciavarella, Grazia; Daniele, Antonio; Bellomo, Antonello; Panza, Francesco; Di Mauro, Lazzaro; Greco, Antonio; Seripa, Davide

doi: 10.1080/17425255.2019.1658742pmid: 31512953

Introduction: Over the last decade, the spread of next-generation sequencing technology along with the rising cost in health management in national health systems has led to widespread use/abuse of pharmacogenetic tests (PGx) in the practice of many clinical disciplines. However, given their clinical significance, it is important to standardize these tests for having an interaction with the clinical analysis laboratory (CAL), in which a PGx service can meet these requirements.Areas covered: A diagnostic test must meet the criteria of reproducibility and validity for its utility in the clinical routine. This present review mainly describes the utility of introducing PGx tests in the CAL routine to produce correct results useful for setting up personalized drug treatments.Expert opinion: With a PGx service, CALs can provide the right tool to help clinicians to make better choices about different categories of drugs and their dosage and to manage the economic impact both in hospital-based settings and in National Health Services, throughout electronic health records. Advances in PGx also allow a new approach for pharmaceutical companies in order to improve drug development and clinical trials. As a result, CALs can achieve a powerful source of epidemiological, clinical, and research findings from PGx tests.

Zhang, Ying; Yan, Hao; Xu, Zhifei; Yang, Bo; Luo, Peihua; He, Qiaojun

doi: 10.1080/17425255.2019.1663169pmid: 31478386

Introduction: The phosphatidylinositide 3-kinase/AKT/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway has emerged as an important target in cancer therapy. Numerous PI3K/AKT/mTOR pathway inhibitors are extensively studied; some are used clinically, but most of these drugs are undergoing clinical trials. Potential adverse effects, such as severe hepatotoxicity and pneumonitis, have largely restricted the application and clinical significance of these inhibitors. A summary of mechanisms underlying the adverse effects is not only significant for the development of novel PI3K/AKT/mTOR inhibitors but also beneficial for the optimal use of existing drugs.Areas covered: We report a profile of the adverse effects, which we consider the class effects of PI3K/AKT/mTOR inhibitors. This review also discusses potential molecular toxicological mechanisms of these agents, which might drive future drug discovery.Expert opinion: Severe toxicities associated with PI3K/AKT/mTOR inhibitors hinder their approval and limit long-term clinical application of these drugs. A better understanding regarding PI3K/AKT/mTOR inhibitor-induced toxicities is needed. However, the mechanisms underlying these toxicities remain unclear. Future research should focus on developing strategies to reduce toxicities of approved inhibitors as well as accelerating new drug development. This review will be useful to clinical, pharmaceutical, and toxicological researchers.