Population Pharmacokinetic Modeling of Pyrazinamide Among Chinese Patients With Drug-Sensitive or Multidrug-Resistant Tuberculosis.

BACKGROUND: Pyrazinamide is used to treat drug-susceptible (DS) and multidrug-resistant (MDR) tuberculosis (TB). This study aimed to characterize the factors associated with the pharmacokinetic parameters of pyrazinamide and evaluate the disposition of the current regimen, which could provide suggestions for adequate dosing strategies for therapeutic targets. METHODS: A population pharmacokinetic model of pyrazinamide was developed based on the data from 499 plasma concentrations from 222 Chinese patients diagnosed with DS or MDR TB. Pyrazinamide exposure was best described using a one-compartment model. RESULTS: No significant differences were observed in the pharmacokinetic parameters between DS and MDR TB. The final covariate model showed that total body weight was the only significant covariate for apparent clearance, which increased by 0.45 L/h with a 10 kg increase in body weight. A simulation showed that for typical subjects weighing 40-80 kg, a fixed dosage of 1500 mg daily had an area under the concentration-time curve from 0 to 24 hours (AUC0-24) of 389.9-716.0 mg·h/L and peak serum concentrations of the drug (Cmax) of 32.2-44.8 mg/L. CONCLUSIONS: Fixed pyrazinamide doses of 1500, 1750, and 2000 mg are recommended for patients weighing 40-70, 70-80, and 80-90 kg, respectively, to achieve the exposure targets of AUC0-24 > 363 mg·h/L or Cmax > 35 mg/L to attain efficacy.

Functional metabolomics characterizes the contribution of farnesoid X receptor in pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome.

Consumption of herbal products containing pyrrolizidine alkaloids (PAs) is one of the major causes for hepatic sinusoidal obstruction syndrome (HSOS), a deadly liver disease. However, the crucial metabolic variation and biomarkers which can reflect these changes remain amphibious and thus to result in a lack of effective prevention, diagnosis and treatments against this disease. The aim of the study was to determine the impact of HSOS caused by PA exposure, and to translate metabolomics-derived biomarkers to the mechanism. In present study, cholic acid species (namely, cholic acid, taurine conjugated-cholic acid, and glycine conjugated-cholic acid) were identified as the candidate biomarkers (area under the ROC curve 0.968 [95% CI 0.908-0.994], sensitivity 83.87%, specificity 96.55%) for PA-HSOS using two independent cohorts of patients with PA-HSOS. The increased primary bile acid biosynthesis and decreased liver expression of farnesoid X receptor (FXR, which is known to inhibit bile acid biosynthesis in hepatocytes) were highlighted in PA-HSOS patients. Furtherly, a murine PA-HSOS model induced by senecionine (50 mg/kg, p.o.), a hepatotoxic PA, showed increased biosynthesis of cholic acid species via inhibition of hepatic FXR-SHP singling and treatment with the FXR agonist obeticholic acid restored the cholic acid species to the normal levels and protected mice from senecionine-induced HSOS. This work elucidates that increased levels of cholic acid species can serve as diagnostic biomarkers in PA-HSOS and targeting FXR may represent a therapeutic strategy for treating PA-HSOS in clinics.

A Synthetic External Control Study Comparing the Clinical Efficacy of Wendan Decoction and 19 Antidepressants.

BACKGROUND: Wendan decoction (WDD) has been used as a treatment for depression in China since the Tang Dynasty. However, high-quality evidence for this is lacking. This study proposed a novel synthetic external control method to evaluate its clinical efficacy. METHODS: We searched public databases for clinical trials of WDD for major depression. The rate of change of the Hamilton Depression Scale score from baseline was used as an efficacy indicator, and a model-based meta-analysis was performed to analyze the clinical efficacy of WDD. To establish a reference standard for efficacy, the antidepressant efficacy distributions of a placebo and 19 antidepressants were virtually synthesized based on the same conditions as the clinical trial characteristics of WDD. RESULTS: This study included 5 clinical trials with 177 participants. WDD showed a slow onset, with a time to reach the maximum effect of 9.71 weeks. At 8 weeks, the rate of change in the Hamilton Depression Scale score from baseline was 66.4% (95% CI = 62.3%-70.3%) in the WDD group. The pure effect value of WDD, after deducting the placebo effect, was 26.9% (95%CI = 23.0%-30.9%), which was comparable with 5 types of antidepressants and significantly higher than the others. CONCLUSION: The proposed external synthetic control method provides a solution to the bottleneck problem of clinical efficacy evaluation in real-world research on traditional Chinese medicine. WDD has high clinical development value for the treatment of depression, and large-scale randomized controlled trials are recommended to confirm its antidepressant effect.

Quantitative comparison of different inhaled corticosteroids in the treatment of asthma in children.

BACKGROUND: The GINA recommends inhaled corticosteroids (ICSs) for the treatment of steps 2-3 of childhood asthma. However, the difference in efficacy between these drugs remains unclear. The purpose of this study was to compare the efficacy of different ICS drugs in the treatment of childhood asthma. METHODS: We searched PubMed and EMBASE for randomized controlled trials of ICSs in the treatment of childhood asthma. Using forced expiratory volume in the first second (FEV1) as the primary outcome, a time-course model of ICSs was constructed. In addition, the symptom-free days% were analyzed as a secondary outcome. RESULTS: Six studies involving 2237 children that reported FEV1 were included. The results showed that the ET50 of ciclesonide (CIC) and budesonide (BUD) was 1.23 and 2.97 weeks, respectively. Compared with them, FP had a higher efficacy. In terms of symptom-free days%, we found that the efficacy of beclometasone dipropionate was lower than that of CIC and fluticasone propionate. CONCLUSION: In this study, the efficacy of three ICS drugs was quantitatively compared, providing necessary information for the implementation of medication guidelines for steps 2-3 of asthma in children. IMPACT: This study analyzed the entire time-course of the drug efficacy of Inhaled corticosteroids in the treatment of asthma in children aged 5-12, which found that although the maximum efficacy of both ciclesonide and budesonide was the same, the onset speed of ciclesonide was faster than that of budesonide. The above information provides the necessary quantitative information for the implementation of medication guidelines for steps 2-3 asthma in children.

Quantitative evaluation of therapy options for relapsed/refractory diffuse large B-cell lymphoma: A model-based meta-analysis.

New therapies for relapsed/refractory diffuse large B-cell lymphoma (r/rDLBCL) have emerged in recent years, but there have been no comprehensive quantitative comparisons of the efficacy of these therapies. In this study, the efficacy characteristics of 11 types of treatment strategy and 63 treatment regimens were compared by model based meta-analysis. We found that compared with monotherapy, association therapy had significant benefits in terms of overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). However, whereas treatment regimens involving chemotherapy contributed to significant improvements in ORR and PFS, OS was not improved. In terms of treatment strategy, we identified chemotherapy in association with immunotherapy sequential autologous stem cell transplantation (ASCT), the association of two different types of immunotherapies, chemotherapy sequential ASCT, chemotherapy in association with immunotherapy, and chemotherapy in association with two types of immunotherapies as showing better efficacy. With respect to specific treatment regimens, we found that the following had better efficacy: rituximab in association with inotuzumab ozogamicin; rituximab in association with carmustine, etoposide, cytarabine, and melphalan sequential ASCT (R-BEAM+ASCT); lenalidomide in association with rituximab, etoposide, cisplatin, cytarabine, and methylprednisolone; iodine-131 tositumomab in association with BEAM sequential ASCT; and chemotherapy sequential chimeric antigen receptor T-cell immunotherapy, with median OS of 48.2, 34.2, 27.8, 25.8, and 25 months, respectively. Moreover, with respect to association therapy, there was a strong correlation between the 6-month PFS and 2-year OS. The findings of this study provide the necessary quantitative information for clinical practice and clinical trial design for the treatment of r/rDLBCL.

LABA/LAMA versus LABA/ICS fixed-dose combinations in the prevention of COPD exacerbations: a modeling analysis of literature aggregate data.

OBJECTIVES: This study aimed to quantitatively compare the efficacy and safety of long-acting ß2-agonist (LABA)/long-acting muscarinic antagonist (LAMA) and LABA/inhaled corticosteroid (ICS) fixed-dose combinations (FDCs) in preventing moderate or severe chronic obstructive pulmonary disease (COPD) exacerbations. METHODS: A literature search was performed using public databases. The time course characteristics of the probability of a moderate or severe exacerbation in stable COPD patients treated with LABA/LAMA and LABA/ICS FDCs were described by the parametric survival function. A random-effects model in a single-arm meta-analysis was used to analyze the incidence of serious adverse events (SAEs) and pneumonia. RESULTS: Twenty studies including 23,955 participants were included. The proportion of participants with a history of COPD exacerbation (%) in the previous year and the postbronchodilator forced expiratory volume in the first second (FEV1) (%predicted) were important factors affecting drug efficacy. After adjusting the above factors to median levels of 100% and 45.5%, respectively, the moderate or severe exacerbation rates at 52 weeks for olodaterol/tiotropium, formoterol/budesonide, indacaterol/glycopyrronium, formoterol/glycopyrronium, vilanterol/fluticasone, salmeterol/fluticasone, and vilanterol/umeclidinium were 38.3%, 41.0%, 42.6%, 47.0%, 47.5%, 47.9%, and 53.0%, respectively. In terms of safety, significant differences were observed among drugs containing different LABA/LAMA FDCs. CONCLUSIONS: This study showed that not all LABA/LAMA FDCs were superior to LABA/ICS FDCs in safety and in preventing moderate or severe exacerbations in patients with stable COPD, providing important quantitative information for COPD-related guidelines.

Population Pharmacokinetic Modeling of Bedaquiline among Multidrug-Resistant Pulmonary Tuberculosis Patients from China.

Bedaquiline has been widely used as a part of combination dosage regimens for the treatment of multidrug-resistant tuberculosis (MDR-TB) patients with limited options. Although the effectiveness and safety of bedaquiline have been demonstrated in clinical trials, limited studies have investigated the significant pharmacokinetics and the impact of genotype on bedaquiline disposition. Here, we developed a population pharmacokinetic model of bedaquiline to describe the concentration-time data from Chinese adult patients diagnosed with MDR-TB. A total of 246 observations were collected from 99 subjects receiving the standard recommended dosage. Bedaquiline disposition was well described by a one-compartment model with first-order absorption. Covariate modeling identified that gamma-glutamyl transferase (GGT) and the single-nucleotide polymorphism (SNP) rs319952 in the AGBL4 gene were significantly associated with the apparent clearance of bedaquiline. The clearance (CL/F) was found to be 1.4 L/h lower for subjects with allele GG in SNP rs319952 than for subjects with alleles AG and AA and to decrease by 30% with a doubling in GGT. The model-based simulations were designed to assess the impact of GGT/SNP rs319952 on bedaquiline exposure and showed that patients with genotype GG in SNP rs319952 and GGT ranging from 10 to 50 U/L achieved the targeted maximum serum concentration at steady state (Cmax,ss). However, when GGT was increased to 100 U/L, Cmax,ss was 1.68-fold higher than the highest concentration pursued. The model developed provides the consideration of genetic polymorphism and hepatic function for bedaquiline dosage in MDR-TB adult patients.

A Real-World Study of Risk Factors for QTc Prolongation in Schizophrenia Patients Receiving Atypical Antipsychotics.

PURPOSE: The risk of sudden cardiac death in patients receiving atypical antipsychotics may be related to QTc prolongation. The aim of this study was to investigate the risk factors for QTc prolongation to prevent QTc prolongation and guide clinical practice. METHODS: All electrocardiogram recordings of 913 schizophrenia patients who were receiving atypical antipsychotics were reviewed for prolonged QTc and associated conditions. Binary logistic regression analysis was used to investigate risk factors for QTc prolongation. RESULTS: Logistic regression analysis demonstrated that sex (odds ratio [OR], 0.386; P = 0.010), age (OR, 1.047; P = 0.000), high-density lipoprotein (OR, 0.257; P = 0.014), and antipsychotics dose (OR, 1.040; P = 0.036) were significantly associated with QTc prolongation. CONCLUSIONS: In patients with male sex, elder age, low high-density lipoprotein, or large antipsychotics dose, QTc should be monitored more frequently.

Quantitative comparison of dose-effect and time-course of fluticasone furoate and fluticasone propionate in adult and adolescent patients with persistent asthma: A systematic review and meta-analysis.

This study aimed to quantitatively compare the efficacy of fluticasone furoate (FF) and fluticasone propionate (FP) in adolescents and adults with asthma. We searched the PubMed and EMBASE databases for placebo-controlled trials that met the inclusion criteria. Pharmacodynamic models were established to describe the time-course of the primary outcome (trough forced expiratory volume in the first second [FEV1 ]). Secondary outcomes (asthma symptoms, quality of life and exacerbations) were also compared via a meta-analysis. A total of 14 articles were included in the analysis, involving 6640 subjects. The efficacy plateau of the two drugs could be reached in 2 weeks. The changes from the baseline in trough FEV1 (95% CI) at week 2 of FF at 200 and 100 µg/day were 0.168 L (0.064-0.199) and 0.127 L (0.048-0.163), respectively. The changes from the baseline in trough FEV1 (95% CI) at week 2 of FP at 1000, 500, 250 and 100 µg/day were 0.133 L (0.049-0.171), 0.127 L (0.043-0.163), 0.117 L (0.039-0.150) and 0.093 L (0.032-0.129), respectively. The efficacy of FP had reached a plateau at the maximum evaluated dose (1000 µg/day), while a plateau effect was not seen at the maximum evaluated dose of FF (200 µg/day). In terms of secondary outcomes, the relative effects of the two drugs relative to the placebo were similar and did not show obvious dose-effect relationships. In this study, the time-course and dose-effect characteristics of FP, FF and placebo were quantitatively evaluated, providing necessary quantitative information for asthma-related guidelines.

Modelling an evaluation of the efficacy and safety of gemcitabine combined with platinum in the treatment of non-small cell lung cancer.

WHAT IS KNOWN AND OBJECTIVES: Gemcitabine combined with platinum is currently the recommended first-line chemotherapy for advanced non-small cell lung cancer (NSCLC). This study aimed to quantitatively compare the efficacy and safety of gemcitabine-platinum combinations in the treatment of advanced NSCLC under different dosing regimens based on extensive literature data. METHODS: The PubMed and Cochrane Library databases were systematically searched for clinical trials in patients with NSCLC treated with a gemcitabine-platinum regimen. A parametric survival function was used to analyse the time course of overall survival (OS). The objective response rate (ORR) and the incidence of grade 3/4 adverse events were summarized using the random-effects model of a single-arm meta-analysis. RESULTS: The study included 63 arms from 47 publications, with a total sample size of 4344 patients for analysis. The model revealed that East Asians has a better survival benefit than non-East Asians, with a median OS of 16.4 (95% CI: 14.3-19.0) and 9.9 (95% CI: 8.1-12.4) months, respectively. Moreover, the OS of patients that underwent a 6-cycle treatment was significantly longer than those that had a 4-cycle treatment in non-East Asians, with a median OS of 10.2 (95% CI: 9.5-11.1) and 8.4 (95% CI: 7.7-9.3) months, respectively. However, the incidence of neutropenia, nausea and vomiting also increased after 6 cycles of treatment. When the dose of gemcitabine increased from 1000 mg/m2 to 1250 mg/m2 , the median OS was extended by approximately 1 month, but the incidence of grade 3/4 adverse reactions did not increase. WHAT IS NEW AND CONCLUSION: Race is an important factor affecting OS in the treatment of advanced NSCLC, which should be considered when conducting international multicentre clinical trials. Additionally, this study found that the OS increased with an increase in gemcitabine exposure, so it is necessary to construct an exposure-response model to obtain the best benefit-risk ratio for patients.

Population pharmacokinetics of tacrolimus in Chinese adult liver transplant patients.

Tacrolimus is widely used in organ transplantation to prevent rejection. However, the narrow therapeutic window and the large inter-and intra-individual variability in the pharmacokinetics (PK) of tacrolimus make it difficult for individualization of dosing. This study aimed at developing a population pharmacokinetic model for estimating the oral clearance of tacrolimus in Chinese liver transplant patients, and identifying factors that contribute to the PK variability of tacrolimus. Data of 151 liver transplant patients who received tacrolimus were analyzed in this study. The population PK model was analyzed and the covariates including population demographic and biochemical characteristics, drug combination, and genetic polymorphism were explored using non-linear mixed-effects modeling approach. A single-compartment population PK model was developed, and the final model was CL/F = (14.6-2.38 × cytochrome P450 (CYP) 3A5-3.72 × WZC+1.04 × (POD/9)+2.48 × COR) × Exp(ηi ), where CYP3A5 was 1 for CYP3A5*3/*3, Wuzhi Capsule (WZC) was 1 when patients took tacrolimus combined with WZC, otherwise it was 0, corticosteroids (COR) was 1 when patients take tacrolimus combined with COR, otherwise, it was 0, POD was the post-operative day. Visual inspection and bootstrap indicated that the final model was stable and robust. In this study, we developed the first tacrolimus population PK model in Chinese adult liver transplant patients. We first determined the influence of WZC on tacrolimus in these people, which could provide useful PK information for the drug combination of tacrolimus and WZC. We also revealed the influence of genetic polymorphism of CYP3A5, POD, and a combination of COR on tacrolimus PK. Therefore, these significant factors should be taken into consideration in optimizing dosage regimens.

The impacts of race and regimens on the efficacy and safety of paclitaxel and platinum combination treatment for patients with advanced non-small cell lung cancer.

PURPOSE: Paclitaxel-platinum chemotherapy is the first-line treatment for advanced non-small cell lung cancer (NSCLC) patients. This study quantitatively evaluated the factors influencing the efficacy and safety of the paclitaxel-platinum regimen to provide the necessary reference for the development of clinical practice and clinical trials. METHODS: A literature search was performed using public databases. The parametric survival function was used to analyze the overall survival (OS) time course of patients treated with the paclitaxel-platinum regimen. The random effects model in the single-arm meta-analysis was used to analyze the objective response rate (ORR) and the incidence of grade 3-4 adverse events (AEs) under the predefined subgroups according to race and the regimen. RESULTS: A total of 31 studies consisting of 3365 participants were included in the analysis. Race was the most important determinant of efficacy and safety in the paclitaxel-platinum regimen, with the median survival time and ORR in East Asians and non-East Asians being 12.2 months (95% CI: 10.5-14.4 months) and 37% (95% CI: 32-41%) and 8.4 months (95% CI: 6.5-11.0 months) and 28% (95% CI: 25-32%), respectively. The incidence of grade 3-4 AEs such as leukopenia and neutropenia was about three times higher in East Asians compared to non-East Asians. CONCLUSIONS: The efficacy and safety of the paclitaxel-platinum regimen can vary between East Asian and non-East Asian populations and between different treatment schedules. The results of this study can provide a reliable and precise external control for the future evaluation of new treatment options for advanced NSCLC.

Analysis of Time-Course, Dose-Effect, and Influencing Factors of Antidepressants in the Treatment of Acute Adult Patients With Major Depression.

OBJECTIVE: Model-based meta-analysis was used to describe the time-course and dose-effect relationships of antidepressants and also simultaneously investigate the impact of various factors on drug efficacy. METHODS: This study is a reanalysis of a published network meta-analysis. Only placebo-controlled trials were included in this study. The change rate in depression rating scale scores from baseline was used as an efficacy indicator because a continuous variable is more likely to reflect subtle differences in efficacy between drugs. RESULTS: A total 230 studies containing 64 346 patients were included in the analysis. The results showed that the number of study sites (single or multi-center) and the type of setting (inpatient or noninpatient) are important factors affecting the efficacy of antidepressants. After deducting the placebo effect, the maximum pure drug efficacy value of inpatients was 18.4% higher than that of noninpatients, and maximum pure drug efficacy value of single-center trials was 10.2% higher than that of multi-central trials. Amitriptyline showed the highest drug efficacy. The remaining 18 antidepressants were comparable or had little difference. Within the approved dose range, no significant dose-response relationship was observed. However, the time-course relationship is obvious for all antidepressants. In terms of safety, with the exception of amitriptyline, the dropout rate due to adverse events of other drugs was not more than 10% higher than that of the placebo group. CONCLUSION: The number of study sites and the type of setting are significant impact factors for the efficacy of antidepressants. Except for amitriptyline, the other 18 antidepressants have little difference in efficacy and safety.

Comparative Efficacy of Drugs for the Treatment of Chronic Constipation: Quantitative Information for Medication Guidelines.

BACKGROUND: Quantitative information is scarce with regard to guidelines for currently prescribed medications for constipation. Furthermore, these guidelines do not reflect the differences in the number of bowel movements caused by each drug. GOALS: In this study, we used a model-based meta-analysis to quantitatively estimate the deviations from the baseline number of spontaneous bowel movements (SBMs) and complete spontaneous bowel movements (CSBMs) associated with pharmacotherapy for chronic constipation to bridge the knowledge gap in the guidelines for current medications. STUDY: A comprehensive survey was conducted using literature databases. In this study, we also included randomized placebo-controlled trials on chronic constipation. Pharmacodynamic models were established to describe the time course of the numbers of SBMs and CSBMs produced by each drug. RESULTS: Data from 20 studies (comprising 9998 participants and 8 drugs) were used to build this model. The results showed that bisacodyl had the greatest effect on increasing the frequency of bowel movements, whereas plecanatide yielded the lowest increase in the number of SBMs and CSBMs. After eliminating the placebo effect, the maximal increase in bowel movement frequency associated with bisacodyl was 6.8 for SBMs (95% confidence interval: 6.1-7.6) and 4.7 for CSBMs (95% confidence interval: 4.3-5.1) per week. These numbers are ∼4 times higher than the number of bowel movements produced by plecanatide. The change in the frequency of SBMs and CSBMs for other drugs, such as sodium picosulfate, velusetrag, linaclotide, elobixibat, lubiprostone, and prucalopride, was similar. The highest increases in the frequency of SBM and CSBM were 2.5 to 4 and 1 to 2.1 per week, respectively. Bisacodyl had the most noticeable loss of efficacy between week 1 and week 4; it reduced the frequencies of SBMs and CSBMs by 2.3 and 2.2, respectively. By contrast, the changes in the frequencies of SBMs and CSBMs were not as great with other drugs. CONCLUSIONS: The data provided in this study may be a valuable supplement to the medication guidelines for the treatment of chronic constipation.

Quantitative comparison of drug efficacy in treating hot flashes in patients with breast cancer.

OBJECTIVE: This study aimed to quantitatively evaluate drug efficacy and identify relevant factors that affect the relief of hot flashes in patients with breast cancer. METHODS: A comprehensive literature search was performed using public databases. Randomized clinical studies on drug therapy for the treatment of hot flashes in patients with breast cancer were identified. A time-effect model was established, and crucial pharmacodynamic parameters, such as maximal efficacy (Emax) and onset time (ET50), were used to reflect the differences in efficacy among the drugs. RESULTS: Eighteen studies involving 5178 subjects were included. It was found that the baseline of hot flashes was an important factor for the Emax value of drugs. After correcting the baseline to the level of eight times per day, the Emax values of progesterone, selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors (SSRIs/SNRIs), neuroleptic agents, tibolone, phytoestrogen, other types of drugs, and placebo were 8.3(95%CI 6.8, 9.9),5.1(95%CI 4.4, 5.7), 4.4(95%CI 3.6, 5.3), 4.0(95%CI 3.6, 4.3), 3.4(95%CI 2.4, 4.3), 2.5(95%CI 0.8, 4.2), and 2.7(95%CI 2.1, 3.3), respectively. The ET50 of all the drugs were approximately 2-2.5 weeks, which was obviously longer than that of the placebo (1.2 weeks). When compared with the previously reported efficacy characteristics in natural menopausal women, no significant difference was found between the two populations. CONCLUSIONS: Progesterone showed the highest efficacy, followed by SSRIs/SNRIs, neuroleptic agents, and tibolone, while phytoestrogen and other types of drugs showed no efficacy advantages. There is a significant association between the baseline of hot flashes and drug efficacy, while there was no significant difference between breast cancer patients and natural menopausal women.

Quantifying placebo responses in clinical evaluation of neuropsychiatric symptoms in Alzheimer's disease.

PURPOSE: This study aimed to establish a non-linear mixed effects model to quantitatively analyze the placebo responses of neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD). METHODS: A comprehensive literature search was conducted in public databases. Placebo-controlled randomized AD clinical trials using the neuropsychiatric inventory (NPI) score as the primary or secondary outcome were included. Non-linear mixed effects model was used to describe the time course of the placebo responses of NPS in AD clinical trials. Potential affecting factors were tested as covariates. RESULTS: A total of 32 clinical studies (involving 3942 subjects) were included in model-based analysis. We found that the maximal placebo responses of NPS were reached at week 4 approximately, after which rebound effects appeared. The baseline NPI score had a significant impact on the placebo responses. Higher baseline NPI score tended to cause greater reductions in NPI score at week 8 and a smaller degree of rebound. For AD patients whose normalized baseline NPI score was 10 points and 30 points, the reduction in normalized NPI score at week 8 was estimated to be 0.83 and 7.43 points, respectively; and the rebound rate after week 8 was estimated to be 0.1 points/week and 0.08 points/week, respectively. CONCLUSIONS: The duration of 4 weeks is sufficient to determine the drug efficacy for assessing NPS in AD clinical trials. The baseline NPI score was a key factor associated with placebo responses of NPS, which should be considered when designing future clinical trials and conducting comparisons across trials.

Efficacy of triptans for the treatment of acute migraines: a quantitative comparison based on the dose-effect and time-course characteristics.

OBJECTIVES: This study aimed to establish a pharmacodynamic model to quantitatively compare the efficacy characteristics of seven kinds of triptans and their different dosage forms in the treatment of acute migraines. METHODS: Clinical studies of triptans in the treatment of acute migraines were comprehensively searched in the public databases. Pharmacodynamic models were established to describe the dose-effect and time-course of each kind of triptan for the proportion of patients who became pain free or had pain relief. RESULTS: A total of 92 articles involving 47,376 subjects were included in the analysis. After eliminating the placebo effect, oral eletriptan (40 mg) had the highest efficacy among all oral drugs at the maximum approved dose, and the proportion of patients who became pain free and had pain relief were 30.9% and 37.9% at 2 h, respectively. However, oral naratriptan (2.5 mg) had the lowest efficacy, and the proportion of patients who became pain free and had pain relief was 10.3% and 21.6% at 2 h, respectively. The efficacy of subcutaneous administration was significantly higher than that of oral administration, and the efficacy of nasal spray administration was comparable to that of oral administration. Regarding the dose-effect, the efficacy of the sumatriptan nasal spray significantly increased within the FDA (Food and Drug Administration)-approved dose range. When the dose was increased from 5 to 20 mg of sumatriptan nasal spray, the proportion of patients who became pain free and had pain relief increased by 16.8% and 18.3% at 2 h, respectively. Regarding the time-course, the time of onset of subcutaneous sumatriptan (6 mg) was the fastest, and the fraction of patients who were pain free at 2 h accounted for 90.6% of that at 4 h. CONCLUSIONS: This study evaluated the efficacy characteristics of seven kinds of triptans and their different dosage forms. The present findings provide necessary quantitative information for migraine medication guidelines.

Population pharmacokinetics of moxifloxacin and its concentration-QT interval relationship modeling in Chinese healthy volunteers.

Moxifloxacin (MX) is an 8-methoxyquinolone antimicrobial drug, which is often used as a positive control in thorough QT (TQT) studies. In the present study we established the population pharmacokinetics model of MX and the relationship of MX concentrations with the QT and various corrected QT (QTc) intervals, and compared the results with other ethnicities. The MX data used for modeling were obtained from a published TQT interval prolongation study of antofloxacin with MX as the positive control. In this four-period crossover study, 24 adult Chinese healthy volunteers received either 200 or 400 mg of oral antofloxacin once daily, 400 mg of MX, or a placebo. Population concentration-effect models were used to investigate the relationship between MX concentrations and QT interval prolongation, baseline-adjusted QTc (ΔQTc), or ΔQTc adjusted with time-matched placebo corrections (ΔΔQTc). The influencing factors of MX PK and the concentration-QTc relationship were determined through covariate screening. Simulation studies were conducted in R2.30 by using the final model with the estimated population mean and intra-individual and inter-individual variability. The estimated pharmacokinetic parameters and the estimated slope of the MX concentration-QT/ΔQTc/ΔΔQTc relationship were described using models and were compared to results for other ethnicities from the literature. We showed that the population pharmacokinetic parameter estimates for total plasma clearance (CL/F), the volume of distribution of central compartment (Vc/F), the distributional clearance in plasma (Q), the volume of distribution of peripheral compartment (Vp/F), and the absorption rate constant (Ka) were 8.22 L/h, 104 L, 3.98 L/h, 37.7 L, and 1.81 1/h, respectively. There was no significant covariate included in the final model. QT interval prolongation of MX estimates ranging from 9.77 to 12.91 ms at the mean average maximum concentration of MX (4.36 µg/mL) and a mean slope ranging from 2.33 to 2.96 ms per µg/mL. In conclusion, no ethnic differences were observed for the MX pharmacokinetic parameters and QT interval prolongation.

Comparative efficacy of nonhormonal drugs on menopausal hot flashes.

PURPOSE: The effects of nonhormonal drugs on menopausal hot flashes are still not well quantified. We therefore did a model-based meta-analysis (MBMA) to quantitate and compare the efficacy features of nonhormonal drugs on menopausal hot flashes. METHODS: Literature was searched in the public databases to extract data of clinical trials on nonhormonal drugs, including selective serotonin reuptake inhibitors (SSRIs) or serotonin norepinephrine reuptake inhibitors (SNRIs), gabapentin, clonidine, and soy isoflavones. Pharmacodynamic models were used for the quantitative analysis of each drug. RESULTS: Thirty-nine studies were included in the analysis. The results revealed a classic pharmacodynamic maximal effect (Emax) model could describe the time course of hot-flash reduction by nonhormonal drugs. After deducting placebo effects, the Emax of SSRIs/SNRIs, gabapentin, clonidine, and soy isoflavones was 13.9 %, 14.8 %, 18.5 %, and 25.0 %, respectively. The time to achieve half of the maximal effect (ET50) of SSRIs/SNRIs, gabapentin, clonidine, and soy isoflavones was 0.18 weeks, 0 weeks, 0 weeks, and 11.6 weeks, respectively. The results showed that SSRIs/SNRIs, gabapentin, and clonidine had a rapid onset, which could reach the maximum effect immediately. However, the onset of soy isoflavones was very slow, and a duration of 16.6 weeks was needed to surpass the efficacy of paroxetine (a type of SSRIs). CONCLUSIONS: The information provided in this study can be used as valuable supplementary information for treatment guidelines of nonhormonal drugs on menopausal hot flashes.

Quantitative efficacy of soy isoflavones on menopausal hot flashes.

AIM: This study aimed to quantitate the efficacy of soy isoflavones in the treatment of menopausal hot flashes. METHODS: Model based meta-analysis (MBMA) was used to quantitate the efficacy of soy isoflavones. We conducted a systemic literature search to build a time-effect model for placebo and soy isoflavones in treating menopausal hot flashes. Studies were identified, subjected to inclusion and exclusion criteria, and reviewed. RESULTS: From 55 articles, 16 studies of soy isoflavones met the inclusion criteria, and contained 65 and 66 mean effect values in placebo and soy isoflavone groups, respectively, from about 1710 subjects. Interestingly, the developed model was found to describe adequately the time course of hot flashes reduction after administration of placebo and soy isoflavones. Using this model, we found that the maximal percentage change of hot flashes reduction by soy isoflavones was 25.2% after elimination of the placebo effect, accounting for 57% of the maximum effects of estradiol (Emax-estradiol = 44.9%). However, a time interval of 13.4 weeks was needed for soy isoflavones to achieve half of its maximal effects, much longer than estradiol, which only required 3.09 weeks. These results suggest that treatment intervals of 12 weeks are too short for soy isoflavones, which require at least 48 weeks to achieve 80% of their maximum effects. CONCLUSIONS: Soy isoflavones show slight and slow effects in attenuating menopausal hot flashes compared with estradiol.