Current Drug Metabolism - Volume 24, Issue 1, 2023

Meropenem, as a carbapenem antibiotic, is commonly used in critically ill pediatric patients with severe infection because of its broad antimicrobial spectrum, high penetration into tissues, and favorable safety profile. Due to pathophysiological changes in critically ill children, the available evidence has demonstrated that the standard dosage regimens of meropenem could not meet an appropriate pharmacodynamic (PD) target attainment in severely infected children. Therefore, we reviewed the pharmacokinetic (PK) profile of meropenem in critically ill children, therapeutic drug monitoring (TDM), and dose optimization based on PK/PD. Meropenem kills bacteria in a timedependent manner and its efficacy is positively correlated with the percentage of the time of dosing interval during which the free serum concentration of meropenem remains above the minimum inhibitory concentration (MIC) of the pathogen (%fT>MIC), which is related to PK/PD targets. For critically ill children, TDM-based dosage optimization and setting even higher PK/PD targets seem necessary to be considered. The currently available studies have revealed that increasing the dose and the application of the extended or continuous infusion of meropenem were able to achieve better PK/PD targets. According to limited clinical data on efficacy and safety, these treatment measures cannot yet be adopted as routine regimens only when serious infections caused by drug-resistant bacteria or strains with high values of MIC are suspected. Further high-quality randomized controlled trials (RCTs) or observational studies with sufficient sample sizes are required to confirm the efficacy and safety of these modes of administration.

Traditional Chinese medicine Heshouwu, named Polygoni Multiflori Radix in Pharmacopoeia of the People’s Republic of China (PPRC, 2020), is derived from the root tuber of Polygonum multiflorum Thunb., Heshouwu or processed Heshouwu is well known for its function in reducing lipids and nourishing the liver. However, increasing cases of Heshouwu-induced hepatotoxicity were reported in recent years. Researchers have begun to study the paradoxical effects of Heshouwu on the liver. 2,3,5,4'-tetrahydroxystilbene-2-&O-β-D-glucoside (TSG), an abundant functional component of Heshouwu, shows various biological activities, among which its effect on the liver is worthy of attention. This paper reviews the current studies of TSG on hepatoprotection and hepatotoxicity, and summarizes the doses, experimental models, effects, and mechanisms of action involved in TSG’s hepatoprotection and hepatotoxicity, aiming to provide insight for future study of TSG and understanding the effects of Heshouwu on the liver. Emerging evidence suggests that TSG ameliorates both pathological liver injury and chemical-induced liver injury by modulating lipid metabolism, inhibiting the inflammatory response and oxidative stress in the liver. However, with the reports of clinical cases of Heshouwu induced liver injury, it has been found that long-term exposure to a high dose of TSG cause hepatocyte or hepatic tissue damage. Moreover, TSG may cause hepatotoxicity by affecting the transport and metabolism of other possible hepatoxic compounds in Heshouwu. Studies indicate that trans-TSG can be isomerized into cis-TSG under illumination, and cis-TSG had a less detrimental dose to liver function than trans- TSG in LPS-treated rats. In brief, TSG has protective effects on the liver, but liver injury usually occurs under highdose TSG or is idiosyncratic TSG-induced liver injury.

Herb medicine has a long history of application and is still used worldwide. With the development of complementary and alternative medicine, the interaction between herb and drugs has attracted more and more attention. Herb-drug interactions (HDI) could cause decreased efficiency, increased toxicity, and affect the drug absorption and disposition processes due to the interference of their pharmacological or pharmacokinetic effects. Hence, the mechanisms and results of herb-pharmacokinetic interactions should be comprehensively summarized. Here, we have summarized the mechanisms of HDI and pharmacokinetic interactions in the last ten years based on searching on PubMed, Science Direct, and Web of Science with different keywords. Besides, the pharmacokinetic interactions were related to nine commonly used herbs and drugs, including Ginseng, Salvia miltiorrhiza, Ginkgo biloba, Garlic, Coptis chinensis, St. John's wort, Ginger, Licorice, Silythistle and Fructus Schisandrae. This review provides an overview of HDI to provide a reference for the rational and safe clinical use of herbs and drugs.

Background: Selection of the optimal antimicrobial posology in critically ill patients remains a challenge, especially in patients with sepsis who undergo continuous renal replacement therapy (CRRT). This systematic review aimed to analyze factors that influence the extracorporeal removal of linezolid. Methods: A comprehensive search was performed to identify studies published up to March 2022 in PubMed, MEDLINE and EMBASE databases. Studies involving adults receiving CRRT and treatment with linezolid were considered eligible if the CRRT setting and linezolid’s pharmacokinetic parameters were clearly mentioned. Results: Six out of 110 potentially relevant studies were included. A total of 101 treatments were identified among 97 enrolled patients. Our analysis showed that continuous veno-venous hemodiafiltration (CVVHDF) was the most frequential used modality (52 cases). Despite distribution volume, the clearance (CL) of linezolid in these studies had large variability. Extracorporeal linezolid removal may be markedly impacted by CRRT dose. There is significant between-subject variability in the probability of pharmacokinetics-pharmacodynamics (PK-PD) target attainment of patients treated with CRRT. Conclusion: Dose adjustment, shortening the dosing interval, and continuous infusion were proposed as regimen optimization. Therapeutic drug monitoring is recommended due to the high variability of linezolid exposure among patients with CRRT, specifically for those whose bodyweight is high, renal function is preserved, and the MIC of infection bacteria is above 2 μg/mL.