Population pharmacokinetics of intravenous colistin sulfate and dosage optimization in critically ill patients.

Aims: To explore the population pharmacokinetics of colistin sulfate and to optimize the dosing strategy for critically ill patients. Methods: The study enrolled critically ill adult patients who received colistin sulfate intravenously for more than 72 h with at least one measurement of plasma concentration. Colistin concentrations in plasma or urine samples were measured by ultraperformance liquid chromatography tandem mass spectrometry (LC-MS/MS). The population pharmacokinetics (PPK) model for colistin sulfate was developed using the Phoenix NLME program. Monte Carlo simulation was conducted to evaluate the probability of target attainment (PTA) for optimizing dosing regimens. Results: A total of 98 plasma concentrations from 20 patients were recorded for PPK modeling. The data were adequately described by a two-compartment model with linear elimination. During modeling, creatinine clearance (CrCL) and alanine aminotransferase (ALT) were identified as covariates of the clearance (CL) and volume of peripheral compartment distribution (V2), respectively. In addition, colistin sulfate was predominantly cleared by the nonrenal pathway with a median urinary recovery of 10.05% with large inter-individual variability. Monte Carlo simulations revealed a greater creatinine clearance associated with a higher risk of sub-therapeutic exposure to colistin sulfate. The target PTA (≥90%) of dosage regimens recommended by the label sheet was achievable only in patients infected by pathogens with MIC ≤0.5 mg/L or with renal impairments. Conclusion: Our study showed that the dose of intravenous colistin sulfate was best adjusted by CrCL and ALT. Importantly, the recommended dosing regimen of 1.0-1.5 million units daily was insufficient for patients with normal renal functions (CrCL ≥80 ml/min) or those infected by pathogens with MIC ≥1.0 mg/L. The dosage of colistin sulfate should be adjusted according to renal function and drug exposure.

Celecoxib-induced drug fever: A rare case report and literature review.

WHAT IS KNOWN AND OBJECTIVE: Drug fever is frequently misdiagnosed, especially during concurrent infection. Celecoxib causes various adverse effects; however, celecoxib-induced drug fever is rarely reported. CASE SUMMARY: A 32-year-old man presented with pyrexia after 17 days of celecoxib therapy, which was reintroduced following 3-day total drug cessation. His fever recurred after this unsuspected rechallenge, which aided in the ultimate identification of the offending drug. A Naranjo Score of 8 led us to infer that drug fever was "probably" caused by celecoxib. WHAT IS NEW AND CONCLUSION: This is the first report of celecoxib-induced drug fever, aimed at assisting its diagnosis, particularly with rarely suspected causative drugs.

External evaluation of published population pharmacokinetic models of polymyxin B.

OBJECTIVES: Several population pharmacokinetics (popPK) models for polymyxin B have been constructed to optimize therapeutic regimens. However, their predictive performance remains unclear when extrapolated to different clinical centers. Therefore, this study aimed to evaluate the predictive ability of polymyxin B popPK models. METHODS: A literature search was conducted, and the predictive performance was determined for each selected model using an independent dataset of 20 patients (92 concentrations) from the Third Xiangya Hospital. Prediction- and simulation-based diagnostics were used to evaluate model predictability. The influence of prior information was assessed using Bayesian forecasting. RESULTS: Eight published studies were evaluated. In prediction-based diagnostics, the prediction error within ± 30% was over 50% in two models. In simulation-based diagnostics, the prediction- and variability-corrected visual predictive check (pvcVPC) showed satisfactory predictivity in three models, while the normalized prediction distribution error (NPDE) tests indicated model misspecification in all models. Bayesian forecasting demonstrated a substantially improvement in the model predictability even with one prior observation. CONCLUSION: Not all published models were satisfactory in prediction- and simulation-based diagnostics; however, Bayesian forecasting improved the predictability considerably with priors, which can be applied to guide polymyxin B dosing recommendations and adjustments for clinicians.

Investigation of the Pharmaceutical Care in One Elderly Parkinson's Disease Patient with Psychotic Symptoms.

A 66-year-old male patient with a 10-year course of Parkinson's disease (PD) was admitted for hallucination lasting a half a month. After treatment with levodopa/carbidopa, selegiline, and piribedil, the patient's motor symptoms were improved while no significant effects were observed on psychotic symptoms. A clinical pharmacist analyzed the pharmacologic and pharmacokinetic characteristics of selegiline and piribedil, summarized the scheme of PD with psychotic symptoms in the literature, and discovered that selegiline might potentiate psychotic side effects of piribedil, while the use of levodopa/carbidopa cannot be ruled out either. Finally, the clinical pharmacist proposed to reduce the dosage of levodopa/carbidopa, increase the dosage of selegiline and quetiapine, and discontinue piribedil. The clinician accepted this suggestion. After the adjustment of medication, the patient's motor symptoms were absolutely improved and the psychotic symptoms were notably improved. This case study suggests that long-term treatment with levodopa/carbidopa and piribedil, along with the progression of the disease itself, could contribute to the emergence of psychotic symptoms in PD. Additionally, selegiline could potentiate psychotic side effects of piribedil. Neurology clinical pharmacists should work alongside neurology clinicians at the bedside to optimize pharmacotherapy, improve patient safety, and contribute to scholarly efforts.

MicroRNA-195 Activates Hepatic Stellate Cells In Vitro by Targeting Smad7.

BACKGROUND AND AIM: Aberrant activation of the TGF-ß1/Smad pathway contributes to the activation of hepatic stellate cells (HSCs). MicroRNA-195 has been shown to regulate the activation of HSCs. The aim of this study was to investigate the role of miRNA-195 in HSCs activation. METHODS: A liver fibrotic rat model induced by diethylnitrosamine was established. Dual luciferase reporter assays were performed to verify that Smad7 was the target of miRNA-195. The expression levels of miR-195, Smad7, and α-SMA in HSC-T6 transfected, respectively, with miR-195 mimic, inhibitor, or control were measured by qRT-PCR. The protein expression of Smad7 was detected by Western blot analysis. RESULTS: Enhanced miR-195 and decreased Smad7 were observed in diethylnitrosamine-induced liver fibrotic rats (P < 0.05). Dual luciferase reporter assays showed that the miR-195 mimic significantly suppressed the luciferase activity of a reporter plasmid carrying the binding site of miR-195 on the 3'UTR of Smad7 (P < 0.05). The miR-195 mimics activated HSCs, further elevated miR-195 and α-SMA (P < 0.01), and reduced the Smad7 level (P < 0.05). The miR-195 inhibitors blocked the activation of HSCs, reduced the expression of miR-195 and α-SMA (P < 0.01), and upregulated the expression of Smad7 (P < 0.05). CONCLUSION: Collectively, we demonstrated that miRNA-195 activated HSCs by targeting Smad7.

[Reversal effect of aloe emodin liposomes on cisplatin resistance line A549/DDP human lung adenocarcinoma cells].

OBJECTIVE: To determine the reversal effect of aloe emodin liposomes (AE-L) on cisplatin resistance human lung adenocarcinoma cell line A549/DDP. METHOD: The un-cytotoxic and cytotoxic concentration of AE-L, and un-cytotoxic concentration of E-L were determined by MTT. The sensitivity of cisplatin were determined by MTT assay in above 3 groups. The intracellular concentration of cisplatin was detected by inductively coupled plasma mass spectrometry (ICP-MS). RESULT: The maximum non-toxic concentration group of AE-L (2.0 mg x L(-1)) increased the sensitivity of cisplatin in A549/DDP, decreased IC50 of cisplatin in A549/DDP from 16.81 mg x L(-1) to 5.86 mg x L(-1), and the hyp-cytotoxic concentration (7.0 mg x L(-1) ) group's IC50 decreased to 4.34 mg x L(-1); AE-L groups significantly increased intracellular concentration of cisplatin in A549/DDP cells. CONCLUSION: The results showed that aloe emodin can reverse multidrug resistance (MDR) of A549/DDP cells and the mechanism might be associated with the increase of intracellular concentration of cisplatin.

[High-performance liquid chromatography-mass spectrometry for determining olmesartan in human plasma].

OBJECTIVE: To establish a simple and rapid HPLC-MS method for determining the contents of olmesartan in human plasma. METHODS: Plasma were precipitated with trifluoroacetic acid, then analyzed on an HyPurity C(18) column (150 mm 2.1 mm, 5 microm). Samples at 40 degrees celsius;. The mobile phase consisted of water-methanol- acetonitrile(14:60:26) with a flow rate of 0.22 ml/min. RESULTS: The lower limit of qualification was 25 microg/L. The calibration curve was linear over the range of 25-3200 microg/L (r=0.9998), with the intra-day and inter-day RSD less than 15%. CONCLUSION: The method is sensitive, rapid and suitable for the study of pharmacokinetics and bioavailability of olmesartan.