Efficacy and safety of perioperative melatonin for postoperative delirium in patients undergoing surgery: a systematic review and meta-analysis

OBJECTIVE

To assess the efficacy and safety of perioperative melatonin and melatonin agonists in preventing postoperative delirium (POD).

METHODS

We conducted a systematic search for randomized controlled trials (RCTs) published through December 2022. The primary outcome was efficacy based on the incidence of POD (POD-I). Secondary outcomes included efficacy and safety according to the length of hospital or intensive care unit stay, in-hospital mortality, and adverse events. Subgroup analyses of POD-I were based on the type and dose of drug (low- and high-dose melatonin, ramelteon), the postoperative period (early or late), and the type of surgery.

RESULTS

In the analysis (16 RCTs, 1981 patients), POD-I was lower in the treatment group than in the control group (risk ratio [RR] = 0.57). POD-I was lower in the high-dose melatonin group than in the control group (RR = 0.41), whereas no benefit was observed in the low-dose melatonin and ramelteon groups. POD-I was lower in the melatonin group in the early postoperative period (RR = 0.35) and in patients undergoing cardiopulmonary surgery (RR = 0.54).

CONCLUSION

Perioperative melatonin or melatonin agonist treatment suppressed POD without severe adverse events, particularly at higher doses, during the early postoperative period, and after cardiopulmonary surgery.

Down-expression of the NLRP3 inflammasome delays the progression of diabetic retinopathy

The investigation aimed to evaluate the effects of Mcc950, an inhibitor of the NLRP3 inflammasome, on diabetic retinopathy (DR) mice. The general physiological condition of each group of mice was recorded. Retinal blood vessels were stained for observation of the density of blood vessels, and retinas were used for further morphological examination and fluorescent staining after the intravitreal injection of Mcc950. Mcc950 partially reversed hyperglycemia-induced vascular damage and had reduced histological changes compared to DR mice. IL-1β production in mice retinas in the diabetic model (DM) group increased, but pretreatment with Mcc950 significantly reversed these changes. Additionally, Mcc950 engineered reduced FITC dextran extravasation and vascular leakage. Therefore, it played an apparent protective role in DR and could be a new treatment strategy for DR.

Effect of enterally administered sleep-promoting medication on the intravenous sedative dose and its safety and cost profile in mechanically ventilated patients: A retrospective cohort study

BACKGROUND

The clinical effect of enteral administration of sleep-promoting medication (SPM) in mechanically ventilated patients remains unclear. This study aimed to investigate the relationship between enteral SPM administration and the intravenous sedative dose and examine the safety and cost of enteral SPM administration.

METHODS

This single-center retrospective cohort study was conducted in a Japanese tertiary hospital intensive care unit (ICU). The exposure was enteral SPM administration during mechanical ventilation. The outcome was the average daily propofol dose per body weight administered as a continuous sedative during mechanical ventilation. Patients were divided into three groups based on the timing of SPM administration at ICU admission: "administration within 48 hours (early administration [EA])," "administration after 48 hours (late administration [LA])," and "no administration (NA)." We used multiple linear regression models.

RESULTS

Of 123 included patients, 37, 50, and 36 patients were assigned to the EA, LA, and NA groups, respectively. The average daily propofol dose per body weight was significantly lower in the EA group than in the LA and NA groups (β -5.13 [95% confidence interval (CI) -8.93 to -1.33] and β -4.51 [95% CI -8.59 to -0.43], respectively). Regarding safety, enteral SPM administration did not increase adverse events, including self-extubation. The total cost of neuroactive drugs tended to be lower in the EA group than in the LA and NA groups.

CONCLUSIONS

Early enteral SPM administration reduced the average daily propofol dose per body weight without increasing adverse events.

NLPR3 inflammasome inhibition alleviates hypoxic endothelial cell death in vitro and protects blood-brain barrier integrity in murine stroke

In ischemic stroke (IS) impairment of the blood-brain barrier (BBB) has an important role in the secondary deterioration of neurological function. BBB disruption is associated with ischemia-induced inflammation, brain edema formation, and hemorrhagic infarct transformation, but the underlying mechanisms are incompletely understood. Dysfunction of endothelial cells (EC) may play a central role in this process. Although neuronal NLR-family pyrin domain-containing protein 3 (NLRP3) inflammasome upregulation is an established trigger of inflammation in IS, the contribution of its expression in EC is unclear. We here used brain EC, exposed them to oxygen and glucose deprivation (OGD) in vitro, and analyzed their survival depending on inflammasome inhibition with the NLRP3-specific drug MCC950. During OGD, EC death could significantly be reduced when targeting NLRP3, concomitant with diminished endothelial NLRP3 expression. Furthermore, MCC950 led to reduced levels of Caspase 1 (p20) and activated Gasdermin D as markers for pyroptosis. Moreover, inflammasome inhibition reduced the secretion of pro-inflammatory chemokines, cytokines, and matrix metalloproteinase-9 (MMP9) in EC. In a translational approach, IS was induced in C57Bl/6 mice by 60 mins transient middle cerebral artery occlusion and 23 hours of reperfusion. Stroke volume, functional outcome, the BBB integrity, and-in good agreement with the in vitro results-MMP9 secretion as well as EC survival improved significantly in MCC950-treated mice. In conclusion, our results establish the NLRP3 inflammasome as a critical pathogenic effector of stroke-induced BBB disruption by activating inflammatory signaling cascades and pyroptosis in brain EC.

Vincristine-induced peripheral neuropathy is driven by canonical NLRP3 activation and IL-1β release

Vincristine is an important component of many regimens used for pediatric and adult malignancies, but it causes a dose-limiting sensorimotor neuropathy for which there is no effective treatment. This study aimed to delineate the neuro-inflammatory mechanisms contributing to the development of mechanical allodynia and gait disturbances in a murine model of vincristine-induced neuropathy, as well as to identify novel treatment approaches. Here, we show that vincristine-induced peripheral neuropathy is driven by activation of the NLRP3 inflammasome and subsequent release of interleukin-1β from macrophages, with mechanical allodynia and gait disturbances significantly reduced in knockout mice lacking NLRP3 signaling pathway components, or after treatment with the NLRP3 inhibitor MCC950. Moreover, treatment with the IL-1 receptor antagonist anakinra prevented the development of vincristine-induced neuropathy without adversely affecting chemotherapy efficacy or tumor progression in patient-derived medulloblastoma xenograph models. These results detail the neuro-inflammatory mechanisms leading to vincristine-induced peripheral neuropathy and suggest that repurposing anakinra may be an effective co-treatment strategy to prevent vincristine-induced peripheral neuropathy.

Dual therapy with an oral non-vitamin K antagonist and a P2Y12 inhibitor vs triple therapy with aspirin, a P2Y12 inhibitor and a vitamin K antagonist for the treatment of diabetes mellitus patients with co-existing atrial fibrillation following percutaneous coronary intervention: A meta-analysis

BACKGROUND

In this analysis, we aimed to compare the efficacy and safety of dual therapy (DT) with a non-vitamin K oral anticoagulant (NOAC) and an adenosine diphosphate receptor antagonist (P2Y12 inhibitor) vs triple therapy (TT) with aspirin, a P2Y12 inhibitor and a vitamin K antagonist for the treatment of diabetes mellitus (DM) patients with co-existing atrial fibrillation (AF) following percutaneous coronary intervention (PCI).

METHODS

Medical Literature Analysis and Retrieval System Online (MEDLINE), http://www.ClinicalTrials.gov, Excerpta Medical data BASE (EMBASE), Web of Science, Cochrane Central and Google Scholar were the searched databases. Studies that were randomized trials or observational studies comparing DT vs TT for the treatment of DM patients with co-existing AF following PCI were included in this analysis. The adverse cardiovascular outcomes and bleeding events were the endpoints. This meta-analysis was carried out by the RevMan version 5.4 software. Risk ratios (RR) with 95% confidence intervals (CI) were used to represent data and interpret the analysis.

RESULTS

A total number of 4970 participants were included whereby 2456 participants were assigned to the DT group and 2514 participants were assigned to the TT group. The enrollment period varied from year 2006 to year 2018. Our current results showed that major adverse cardiac events (RR: 1.00, 95% CI: 0.84-1.20; P = .98), mortality (RR: 1.08, 95% CI: 0.78-1.48; P = .66), myocardial infarction (RR: 1.02, 95% CI: 0.74-1.42; P = .90), stroke (RR: 0.94, 95% CI: 0.53-1.67; P = .84) and stent thrombosis (RR: 1.09, 95% CI: 0.56-2.10; P = .80) were similar with DT versus TT in these patients. However, the risks for total major bleeding (RR: 0.66, 95% CI: 0.54-0.82; P = .0001), total minor bleeding (RR: 0.74, 95% CI: 0.64-0.85; P = .0001), Thrombolysis in Myocardial Infarction (TIMI) defined major bleeding (RR: 0.58, 95% CI: 0.35-0.95; P = .03), TIMI defined minor bleeding (RR: 0.62, 95% CI: 0.42-0.92; P = .02), intra-cranial bleeding (RR: 0.34, 95% CI: 0.13-0.95; P = .04) and major bleeding defined by the International Society on Thrombosis and Hemostasis (RR: 0.68, 95% CI: 0.51-0.90; P = .008) were significantly higher with TT.

CONCLUSIONS

DT with a NOAC and a P2Y12 inhibitor was associated with significantly less bleeding events without increasing the adverse cardiovascular outcomes when compared to TT with aspirin, a P2Y12 inhibitor and a Vitamin K antagonist for the treatment of DM patients with co-existing AF following PCI. Hence, DT is comparable in efficacy, but safer compared to TT. This interesting hypothesis will have to be confirmed in future studies.

Preventative effects of ramelteon against postoperative delirium after elective liver resection

Background

Postoperative delirium was reported to be associated with increased postoperative mortality after liver resection. Therefore, it is crucial to prevent postoperative delirium in such cases. Ramelteon, an agonist of melatonin receptor has been suggested to be useful for preventing delirium. The aim of this study was to examine whether ramelteon is effective at preventing delirium after elective liver resection.

Methods

The cases of patients who underwent liver resection at Nara Medical University (Nara, Japan) between January 2014 and August 2018 were analyzed. During the period from January 2017 to August 2018, ramelteon was prospectively administered to patients who underwent liver resection [8 mg/day on the day before surgery and on postoperative days 1 to 3] (ramelteon group), whereas ramelteon was not administered during the period from January 2014 to December 2016 (control group). The perioperative outcomes of the two groups were compared.

Results

There were 120 patients in the ramelteon group and 186 patients in the control group. No significant intergroup differences in background factors, including age, gender, and preoperative serological laboratory data, were detected. The incidence of postoperative delirium was significantly lower in the ramelteon group (5.8% vs. 15.1%, P = 0.035). Multivariate analysis revealed that being aged ≥75 (P = 0.002), being male (P = 0.020), cardiovascular disease (P = 0.023), blood loss ≥1000ml (P = 0.001) and the absence of ramelteon treatment (P = 0.046) were independent risk factors for postoperative delirium.

Conclusion

The administration of ramelteon might reduce the risk of postoperative delirium after elective liver resection.

Non-GABA sleep medications, suvorexant as risk factors for falls: Case-control and case-crossover study

The aim of this study was to examine the risk of falls associated with the use of non-gamma amino butyric acid (GABA) sleep medications, suvorexant and ramelteon. This case-control and case-crossover study was performed at the Kudanzaka Hospital, Chiyoda Ward, Tokyo. A total of 325 patients who had falls and 1295 controls matched by sex and age were included. The inclusion criteria for the case group were hospitalized patients who had their first fall and that for the control were patients who were hospitalized and did not have a fall, between January 2016 and November 2018. The internal sleep medications administered were classified as suvorexant, ramelteon, non-benzodiazepines, benzodiazepines, or kampo. In the case-control study, age, sex, clinical department, the fall down risk score, and hospitalized duration were adjusted in the logistic regression model. In the case-control study, multivariable logistic regression showed that the use of suvorexant (odds ratio [OR]: 2.61, 95% confidence interval [CI]: 1.29-5.28), nonbenzodiazepines (OR: 2.49, 95% CI: 1.73-3.59), and benzodiazepines (OR: 1.65, 95% CI: 1.16-2.34) was significantly associated with an increased OR of falls. However, the use of ramelteon (OR: 1.40, 95% CI: 0.60-3.16) and kampo (OR: 1.55, 95% CI: 0.75-3.19) was not significantly associated with an increased OR of falls. In the case-crossover study, the use of suvorexant (OR: 1.78, 95% CI: 1.05-3.00) and nonbenzodiazepines (OR: 1.63, 95% CI: 1.17-2.27) was significantly associated with an increased OR of falls. Similar patterns were observed in several sensitivity analyses. It was suggested that suvorexant increases the OR of falls. This result is robust in various analyses. This study showed that the risk of falls also exists for non-GABA sleep medication, suvorexant, and thus it is necessary to carefully prescribe hypnotic drugs under appropriate assessment.

Enhanced bioactive compound production in broccoli cells due to coronatine and methyl jasmonate is linked to antioxidative metabolism

Elicited broccoli suspension-cultured cells (SCC) provide a useful system for obtaining bioactive compounds, including glucosinolates (GS) and phenolic compounds (PCs). In this work, coronatine (Cor) and methyl jasmonate (MJ) were used to increase the bioactive compound production in broccoli SCC. Although the use of Cor and MJ in secondary metabolite production has already been described, information concerning how elicitors affect cell metabolism is scarce. It has been suggested that Cor and MJ trigger defence reactions affecting the antioxidative metabolism. In the current study, the concentration of 0.5 μM Cor was the most effective treatment for increasing both the total antioxidant capacity (measured as ferulic acid equivalents) and glucosinolate content in broccoli SCC. The elicited broccoli SCC also showed higher polyphenol oxidase activity than the control cells. Elicitation altered the antioxidative metabolism of broccoli SCC, which displayed biochemical changes in antioxidant enzymes, a decrease in the glutathione redox state and an increase in lipid peroxidation levels. Furthermore, we studied the effect of elicitation on the protein profile and observed an induction of defence-related proteins. All of these findings suggest that elicitation not only increases bioactive compound production, but it also leads to mild oxidative stress in broccoli SCC that could be an important factor triggering the production of these compounds.

Factors associated to adequate time in therapeutic range with oral vitamin K antagonists in Tunisia

INTRODUCTION

  The quality of chronic anticoagulation and predictor factors of poor anticoagulant control in patients under acenocoumarol were unknown in North Africa.

METHODS

It is an observational study, carried out between November 2015 and November 30, 2016. The international normalized ratio (INR) values were prospectively obtained, and TTR was calculated using the Rosendaal method.

RESULTS

Overall, 215 patients were included in this study, with a mean age of 63±0,8 years. The prevalence of poor anticoagulation control was 78.1%; 95% CI [72.2-83.2] (168 patients with TTR less than 65%). The median TTR with the Rosendaal method was 44.4%. After multivariate adjustment, variables significantly associated with adequate anticoagulation level were: history of ischemic stroke (Adjusted OR equal to 4.3, 95% CI: 1.4-12.9), associated prescription of antiplatelet therapy (Adjusted OR equal to 3.5, 95% CI: 1.1-11.2), daily prescribed dose of coumarins less than 6 mg (Adjusted OR equal to 6.4, 95% CI: 1.1- 36) and lower risk of bleeding assessed as HAS-BLED score (Adjusted OR: 0.5, 95% CI: 0.3-0.8).

CONCLUSION

The quality of anticoagulation management with VKA among outpatients who received acenocoumarol was suboptimal. Strategies should be undertaken by clinicians and patients to improve the quality of anticoagulation, to address challenges to adverse cardiovascular outcomes in individuals treated with chronic anticoagulation.

A survey of the effects of ramelteon on benzodiazepine-dependence: Comparison between a ramelteon add-on group and a continuous benzodiazepine administration group

In general, long-term benzodiazepine hypnotics are prescribed for patients in whom it is difficult to reduce benzodiazepine hypnotics. Unlike benzodiazepine receptor (BZ)-mediated sleep agents, ramelteon induces quasi-natural physiological sleep owing to its mechanism of action. We conducted a survey of ramelteon and BZ-dependence in patients with insomnia. Study subjects were patients with insomnia (42 cases), who were divided into a ramelteon group (22 cases; administered 8 mg/day of ramelteon before sleep in addition to BZ) and a control group (20 cases; continually administered only BZs), with a mean disease duration of 11.3 ± 9.6 years. All data were analyzed using two-way repeated measures analysis of variance. No significant difference was observed between the ramelteon group and the control group when a questionnaire concerning BZ-dependence and withdrawal symptoms was used. A significant improvement in scores at Week 16 from those at Week 0 was observed in the Pittsburgh Sleep Quality Index excerpt and in the Global Assessment of Functioning in the ramelteon group [corrected].The Wilcoxon rank-sum test showed that the number of concomitantly used BZ hypnotics decreased significantly in the ramelteon group after Week 16, while no such change was observed in the control group. Thus, by adding ramelteon to therapy for patients with long-term insomnia, we were able to reduce the number of benzodiazepine hypnotics that were used concomitantly.

Transport and metabolism behavior of brazilein during its entrance into neural cells

Brazilein, a natural small molecule, shows a variety of pharmacological activities, especially on nervous system and immune system. As a potential multifunctional drug, we studied the distribution and the transport behavior and metabolic behavior of brazilein in vivo and in vitro. Brazilein was found to be able to distribute in the mouse brain and transport into neural cells. A metabolite was found in the brain and in the cells. Positive and negative mode-MS/MS and Q-TOF were used to identify the metabolite. MS/MS fragmentation mechanisms showed the methylation occurred at the 10-hydroxyl of brazilein (10-O-methylbrazilein). Further, catechol-O- methyltransferase (COMT) was confirmed as a crucial enzyme correlated with the methylated metabolite generation by molecular docking and pharmacological experiment.

Positive selection in the chromosome 16 VKORC1 genomic region has contributed to the variability of anticoagulant response in humans

VKORC1 (vitamin K epoxide reductase complex subunit 1, 16p11.2) is the main genetic determinant of human response to oral anticoagulants of antivitamin K type (AVK). This gene was recently suggested to be a putative target of positive selection in East Asian populations. In this study, we genotyped the HGDP-CEPH Panel for six VKORC1 SNPs and downloaded chromosome 16 genotypes from the HGDP-CEPH database in order to characterize the geographic distribution of footprints of positive selection within and around this locus. A unique VKORC1 haplotype carrying the promoter mutation associated with AVK sensitivity showed especially high frequencies in all the 17 HGDP-CEPH East Asian population samples. VKORC1 and 24 neighboring genes were found to lie in a 505 kb region of strong linkage disequilibrium in these populations. Patterns of allele frequency differentiation and haplotype structure suggest that this genomic region has been submitted to a near complete selective sweep in all East Asian populations and only in this geographic area. The most extreme scores of the different selection tests are found within a smaller 45 kb region that contains VKORC1 and three other genes (BCKDK, MYST1 (KAT8), and PRSS8) with different functions. Because of the strong linkage disequilibrium, it is not possible to determine if VKORC1 or one of the three other genes is the target of this strong positive selection that could explain present-day differences among human populations in AVK dose requirement. Our results show that the extended region surrounding a presumable single target of positive selection should be analyzed for genetic variation in a wide range of genetically diverse populations in order to account for other neighboring and confounding selective events and the hitchhiking effect.

Ramelteon in the treatment of chronic insomnia: systematic review and meta-analysis

OBJECTIVE

As a melatonin receptor agonist, ramelteon has been approved in the United States as a treatment for insomnia. As a potential alternation, ramelteon should be further evaluated in different doses and populations. This systematic review with meta-analysis aims to determine the efficacy and safety of ramelteon in the treatment of chronic insomnia.

METHODS

We systematically searched and identified in Medline, Embase, PsycINFO and Cochrane Library until September 2011. We only included randomised controlled trials focused on ramelteon, vs. placebo, or any other treatment for patients with chronic insomnia. Data were extracted and evaluated by two independent investigators. If neither clinical nor statistical heterogeneity was found, we pooled results using a fixed-effect model.

RESULTS

Eight studies were selected to include from 175 identified references. There were significant improvements in all the outcomes (subjective and polysomnographic sleep latency, total sleep time and latency to REM), except for the percentage of REM. By subgroup analysis, subjective sleep latency was reduced only in the patients of 18-64 years old, without in the patients over 65 years old. For the safety, ramelteon was not associated with higher risk ratio of any frequent adverse events comparing with control.

CONCLUSION

The efficacy and safety of ramelteon are promising for the chronic insomnia patients. More researches are required for robust conclusions, particularly well-designed; double-blind randomised controlled trials with higher doses of ramelteon (32 or 64 mg) for the older population comparing with other sedative hypnotics.

Pharmacokinetics of valerenic acid in rats after intravenous and oral administrations

Valerenic acid (VA), a sesquiterpenoid, is one of the major secondary bioactive metabolites of VALERIANA OFFICINALIS L. Until now IN VIVO studies on the absorption, bioavailability, disposition, and metabolism of VA are limited. We established and validated an LC-MS/MS assay for the determination of VA in rat plasma and successfully used this method for pharmacokinetic studies in rats after intravenous (i. v.) and oral administrations. The plasma concentration-time data was analyzed by both non-compartmental and compartmental approaches using WinNonlin software. Following i. v. administration, the disposition of VA in rat plasma was biphasic, subdivided into a fast distribution and a slow elimination phase. The half-life of the distribution phase was 6-12 min, and that of the terminal elimination phase 6-46 h, indicating a possible large tissue binding. Disposition PK of valerenic acid after oral treatment was also described by a two-compartment model with a clearance (CL/F) of 2-5 L · h (-1) · kg (-1) and volume of distribution of (V (d)) 17-20 L · kg (-1). The extent of absorption (F) after oral administration was estimated to be 33.70 % with a half-life of 2.7-5 h. Dose proportionality was observed in terms of dose and AUCs, suggesting linear pharmacokinetics at the dose levels studied in rats.

Gender differences in highway driving performance after administration of sleep medication: a review of the literature

OBJECTIVES

It is generally assumed that there are minimal gender differences in the safety and efficacy of central nervous system drugs, as is evidenced by men and women receiving the same drug dosage. There is, however, evidence that drugs may have a differential effect on performance in men and women, given reported differences in pharmacokinetics as well as the presence or absence and severity of adverse effects. It is especially important to verify whether gender differences in performance exist in case of activities that have potentially dangerous outcomes such as driving a car. This review summarizes the current scientific evidence on gender differences in driving performance after treatment with hypnotic drugs.

METHODS

A literature search was conducted to obtain all studies that conducted on-road driving tests to examine the effects hypnotic drugs on driving. Cross-references were checked and technical reports and raw data were obtained, if possible.

RESULTS

Fourteen studies were evaluated. Many studies did not allow analyses of gender effects because only women were included. Others did not report data on gender analyses. Technical reports and additional data analyses revealed significant gender differences in driving performance the morning following bedtime administration of flurazepam (30 mg) and after middle-of-the-night administration of zolpidem (10 mg). No significant gender differences were found for ramelteon (8 mg), lormetazepam (1 and 2 mg), zaleplon (10 and 20 mg), and zopiclone (7.5 mg).

CONCLUSIONS

Although the available data are limited, the results show that significant gender differences have been found for some drugs but not others. Therefore, in the future more research is needed to reveal potential gender differences and to determine what mediates them.

Effectiveness of ramelteon for insomnia symptoms in older adults with obstructive sleep apnea: a randomized placebo-controlled pilot study

STUDY OBJECTIVES

To evaluate the effectiveness of ramelteon, a melatonin receptor agonist, for the treatment of insomnia in older adults starting auto-titrating positive airway pressure (APAP) therapy for sleep apnea.

METHODS

A parallel group, randomized, double-blind, placebo-controlled pilot effectiveness clinical trial. The study enrolled 21 research study participants who were ≥ 60 years old and had obstructive sleep apnea, defined by an apnea-hypopnea index (AHI) ≥ 5 events/h, with complaints of insomnia. The primary outcome measure was change in sleep onset latency determined from polysomnography at 4 weeks. Research study participants, all of whom were starting on APAP, were randomized to ramelteon 8 mg (n = 8) or placebo (n = 13).

RESULTS

Ramelteon treatment was associated with a statistically significant difference in sleep onset latency (SOL) as measured by polysomnography of 28.5 min (± 16.2 min) compared to placebo (95% C.I. 8.5 min to 48.6 min, effect size 1.35, p = 0.008). This was due to a 10.7 (± 17.0) min SOL reduction in the ramelteon arm and a 17.8 (± 23.5) min SOL increase in the placebo arm. No change was noted in subjective sleep onset latency (-1.3 min, ± 19.3 min, 95% C.I.: -21.4 min to 18.7 min). No statistically significant changes were noted in the AHI, sleep efficiency (polysomnography and self-report), APAP adherence, Pittsburgh Sleep Quality Index global score, or Epworth Sleepiness Scale score when comparing ramelteon vs. placebo. Four adverse events occurred in the ramelteon arm and 2 in the placebo arm; none were considered to be related to treatment.

CONCLUSIONS

Ramelteon was effective in improving objective, but not subjective, sleep onset latency even in older adults who were starting APAP therapy for sleep apnea. Further research is warranted in examining the role of ramelteon in the care of older adults with insomnia symptoms and sleep apnea.

Ramelteon prior to a short evening nap impairs neurobehavioral performance for up to 12 hours after awakening

STUDY OBJECTIVES

Planned naps can improve performance when the habitual or nocturnal sleep schedule is disrupted. It may be difficult, however, to achieve sleep during a nap, particularly during the circadian peak in alertness in the early evening. Prior studies with the melatonin agonist, ramelteon, reported that this hypnotic does not impair neurobehavioral performance. We tested whether ramelteon could improve nap efficiency in the early evening and subsequent performance during a simulated 8-h night shift.

METHODS

10 healthy volunteers aged 19-31 years participated in an inpatient randomized, double-blind, placebo-controlled crossover study. Ramelteon 8 mg or placebo was administered 30 min prior to a 2-h nap opportunity commencing 13 h after each individual's habitual morning wake time.

RESULTS

Ramelteon did not significantly affect sleep efficiency during the nap prior to the night shift. Following the nap, ramelteon was associated with significantly worse neurobehavioral performance on assessments immediately following the nap and during the simulated night shift.

CONCLUSIONS

Although ramelteon did not significantly affect sleep during the nap, it was associated with significant impairments in neurobehavioral performance for up to 12 h after administration. High homeostatic sleep pressure combined with the circadian performance nadir may increase the vulnerability to hypnotic-induced neurobehavioral impairments. The findings do not support the use of ramelteon prior to an evening prophylactic nap, as there may be residual effects that last for several hours. Furthermore, this study highlights the pitfalls of applying side-effect profiles obtained in one context to another.

[Effect of brazilein on energy metabolism of cerebral ischemia-reperfusion in mice]

OBJECTIVE

To investigate brazilein's role in energy metabolism of cerebral ischemia-reperfusion in mice.

METHOD

Fourty mice were randomly divided into the sham group, ischemia group, brazilein 5 mg x kg(-1) group and brazilein 10 mg x kg(-1) group, each with ten cases. Cerebral ischemia model was the built. Mice were injected with brazilein three days before the operation, then they were killed. Cerebrum homogenate was prepared for the detecting of ATP, ADP, AMP and lactic acid by HPLC, expressions of MCT1 and MCT2 in mRNA level by RT-PCR.

RESULT

The lactic acid in cerebrum increased sharply 20 minutes after cerebral ischemia and decreased 1 hour after reperfusion, then returned to the normal level 24 hours after reperfusion. The charge of energy decreased significantly at the beginning of the ischemia-reperfusion, and the charge restored 1 hour after reperfusion though it was still much lower than the normal level at the time point of 24 hours. Moreover, MCT1 and MCT2 upregulated accompanied with the increase of lactate, MCT2 mRNA enhanced in brazilein 5 mg x kg(-1) group (P < 0.05) while both the two factors increased in brazilein 10 mg x kg(-1) group (P < 0.01).

CONCLUSION

Brazilein might protect neurons by changing the charge of energy.

Ramelteon: application withdrawn. Ramelteon in insomnia: withdrawal of marketing application in patients' best interests

The European Committee for Medicinal Products for Human Use (CHMP) has issued a negative opinion on the use of the melatonin receptor agonist ramelteon in insomnia, due to its unfavourable risk-benefit balance. In France, melatonin itself is licensed for use in this indication.

Effects of ramelteon 8 mg on objective sleep latency in adults with chronic insomnia on nights 1 and 2: pooled analysis

OBJECTIVE

Ramelteon is an MT(1)/MT(2) melatonin receptor agonist indicated for the treatment of insomnia characterized by difficulty with sleep onset. In previous clinical studies, ramelteon reduced latency to persistent sleep (LPS) in subjects with chronic insomnia. The goal of the current analysis was to determine the average reduction in LPS and overall adverse event profile for subjects taking ramelteon 8 mg.

RESEARCH DESIGN AND METHODS

This pooled analysis examined four randomized, double-blind, placebo-controlled clinical trials of ramelteon in subjects with chronic insomnia. The analysis included adults (age 18-83 years) with chronic insomnia who took ramelteon 8 mg or placebo. The primary endpoint of each trial was mean LPS, measured by polysomnography (PSG) on nights 1 and 2. Adverse events were collected for all subjects for the duration of each trial.

RESULTS

Efficacy data were available for 566 subjects who took ramelteon 8 mg (mean age 46.7 years) and 556 subjects who took placebo (mean age 47.8 years). Mean LPS at baseline was 66.6 min for the placebo group and 66.9 min for the ramelteon group. At nights 1 and 2, mean LPS for the ramelteon 8 mg group (30.2 min) was significantly less than the mean LPS for the placebo group (43.3 min). The least squares mean difference from placebo was -13.1 min (p < 0.001). Headache (8.9% ramelteon 8 mg, 8.8% placebo) and somnolence (3.5% ramelteon 8 mg, 0.7% placebo) were the most common adverse events.

CONCLUSIONS

Ramelteon 8 mg, on average, reduced LPS by approximately 13 min more than placebo on nights 1 and 2 of treatment in adults with chronic insomnia. Ramelteon was well tolerated with a low incidence of adverse events. This mean reduction in LPS versus placebo is similar to what has been reported for other classes of insomnia medications. However, these results reflect nights 1 and 2 of treatment and may not be representative of longer treatments.

Effect of ramelteon on middle-of-the-night balance in older adults with chronic insomnia

STUDY OBJECTIVES

To evaluate the effect of ramelteon on middle-of-the-night balance, mobility, and memory in older insomniacs.

METHODS

Thirty-three older adults (age > or = 65 years) with insomnia were enrolled in a single-dose, 3-way crossover study of balance after bedtime administration of ramelteon, 8 mg; zolpidem, 10 mg (positive control); or placebo. Subjects were administered study medication 30 minutes before bedtime and were awakened 2 hours after dosing to evaluate balance (Sensory Organization Test), turning speed and stability, memory (immediate and delayed word recall), and adverse events. There was a 4- to 10-day washout between treatments.

RESULTS

Ramelteon or zolpidem (positive control) was compared with placebo. There were no differences between placebo and ramelteon on the Sensory Organization Test (p = 0.837), turn time (p = 0.776), or turn sway (p = 0.982). The positive control (zolpidem) did reveal significant impairments on the Sensory Organization Test, turn time, and turn sway (p < 0.001, all). Immediate and delayed memory recall were not significantly different with ramelteon (p = 0.683 and p = 0.650, respectively). Immediate recall declined significantly with zolpidem (p = 0.002). Adverse events were infrequent (ramelteon, n = 7; placebo, n = 7; zolpidem, n = 13); none were serious.

CONCLUSION

In older adults, ramelteon did not impair middle-of-the night balance, mobility, or memory relative to placebo.

Ramelteon for insomnia symptoms in a community sample of adults with generalized anxiety disorder: an open label study

OBJECTIVE

Prior research confirms the relationship between insomnia and psychiatric disorders, particularly anxiety and depression. The effectiveness and tolerability of ramelteon was examined in adult generalized anxiety disorder (GAD) patients with insomnia symptoms.

METHODS

Twenty-seven adults with sleep disturbance meeting DSM-IV diagnostic criteria for GAD and partially responsive on an SSRI or SNRI by randomization visit (as signified by a Hamilton Anxiety scale [HAMA] maximum score of 15 and minimum of 8, Clinical Global Impressions Severity of Illness [CGI-S] scale of < or = 4 and > or = 2 [measuring anxiety symptoms], CGI-S of 4 [measuring insomnia symptoms], > or = 5 on the Pittsburgh Sleep Quality Index [PSQI], and > or = 10 on the Epworth Sleepiness Scale [ESS]) were treated openly for 10 weeks on ramelteon 8 mg at bedtime. Analysis was conducted using repeated measures methodology. Patient reported sleep diaries were maintained throughout the study.

RESULTS

Significant symptom reduction was observed on all scales (HAMA, ESS, CGI-I, CGI-S), with subjects falling asleep faster and sleeping longer. Headache upon stopping ramelteon, daytime tiredness, agitation, and depression were the most commonly reported side effects and were cited as transient.

CONCLUSION

Data from this 12-week open-label study suggests ramelteon is an effective and generally well tolerated treatment for insomnia symptoms in this community sample of adults with GAD.

Ramelteon: new drug. Insomnia: no role for risky placebos

(1) Patients complaining of insomnia should first be treated with non-drug measures (information, advice). Short-course benzodiazepine therapy can be tried if non-drug measures and established herbal remedies fail; (2) Ramelteon, a drug that antagonises receptors for melatonin, a hormone involved in circadian rhythms, is being considered for European marketing authorization in the treatment of insomnia; (3) Ramelteon has only been compared with placebo in clinical trials. Only one of three trials in which the patients were studied in their normal environment showed that ramelteon reduced the time to sleep onset, only by about 10 minutes. A similar reduction was observed in the artificial conditions of a sleep laboratory. There was no effect on sleep duration or on the number of night-time awakenings; (4) Ramelteon does not appear to have the disadvantages of benzodiazepines, such as residual daytime drowsiness, rebound insomnia on drug withdrawal, and dependence. But ramelteon provokes hyperprolactinaemia and was carcinogenic in experimental animals; (5) In practice, when a drug is needed for a patient complaining of insomnia, the best options are phytotherapy or short-course benzodiazepine treatment.

Evaluation of the efficacy and safety of ramelteon in subjects with chronic insomnia

OBJECTIVE

To evaluate efficacy and safety of ramelteon (MT1/MT2-receptor [corrected] agonist) in subjects with chronic primary insomnia.

METHODS

Randomized, multicenter, double-blind, placebo-controlled trial of nightly ramelteon treatment (8 mg or 16 mg) in adults (N=405) with primary chronic insomnia (DSM-IV-TR). Latency to persistent sleep (LPS), TST, sleep efficiency, wake time after sleep onset, and number of awakenings were measured by polysomnography. Subject-reported measures were also assessed.

RESULTS

LPS at Week 1 (primary measure) was significantly shorter with ramelteon 8 mg (32.2 min) or 16 mg (28.9 min) vs placebo (47.9 min; p <0.001). Significant improvements in LPS were maintained at Weeks 3 and 5. TST was significantly longer with both doses of ramelteon at Week 1 (p <0.001) vs placebo. Subject-reported sleep latency was significantly shorter with ramelteon 8 mg at Weeks 1, 3, and 5 (p <0.001) and ramelteon 16 mg at Weeks 1 and 3 (p < or =0.050) vs placebo. Wake time after sleep onset and number of awakenings were not significantly different with ramelteon 8 mg or 16 mg treatment vs placebo. Subjective TST was significantly longer with ramelteon 8 mg at Weeks 1, 3, and 5 (p < or =0.050) and ramelteon 16 mg at Week 1 (p = 0.003) vs placebo. Ramelteon had no clinically meaningful effect on sleep architecture, next-morning psychomotor tasks, alertness, or ability to concentrate. No withdrawal or rebound effects were observed.

CONCLUSIONS

Ramelteon reduced LPS over 5 weeks of treatment in subjects with chronic insomnia, with no clinically meaningful sleep architecture alterations, next-morning residual pharmacologic effects, and no evidence of rebound insomnia or withdrawal. No numerical differences were observed between the 2 doses of ramelteon.

A 2-night, 3-period, crossover study of ramelteon's efficacy and safety in older adults with chronic insomnia

OBJECTIVE

To assess the efficacy and safety of ramelteon, a selective melatonin MT1/MT2-receptor agonist, for insomnia treatment in older adults.

METHODS

In a randomized, 9-week, 3-period crossover trial conducted at 17 sleep centers, older adults (N = 100) with chronic primary insomnia (37 men, 63 women; mean age [range], 70.7 [65-83] years) were administered placebo, ramelteon 4 mg, and ramelteon 8 mg in three treatment phases for two consecutive nights. Each phase was separated by 5- to 12-day washout periods. Sleep was monitored via polysomnography. Subjective sleep parameters, using a Postsleep Questionnaire, were recorded, and residual pharmacologic effects were assessed.

RESULTS

Statistically significant reductions in latency to persistent sleep were observed with both ramelteon 4 mg and 8 mg compared to placebo (28.7 min vs. 38.4 min, p < 0.001; 30.8 min vs. 38.4 min, p = 0.005, respectively). Total sleep time (p = 0.036 and p = 0.007, respectively) and sleep efficiency (p = 0.037 and p = 0.007, respectively) were also significantly improved with ramelteon 4 mg and 8 mg compared to placebo. Statistically significant reductions in subjective sleep latency on a Postsleep Questionnaire were reported with ramelteon 4 mg versus placebo (p = 0.037), but not ramelteon 8 mg (p = 0.120); no significant differences on other subjective sleep assessments were reported. A lack of power limits interpretation of self-reported sleep parameters. Incidences of adverse events considered treatment related were placebo (7%), ramelteon 4 mg (11%), and ramelteon 8 mg (5%). No residual pharmacologic effects were observed via Digit Symbol Substitution Test, memory recall tests (immediate and delayed), visual analog scales (feelings and mood), and Postsleep Questionnaire (level of alertness and ability to concentrate).

CONCLUSIONS

In older adults with chronic primary insomnia, ramelteon produced significant reductions in latency to persistent sleep and increases in total sleep time and sleep efficacy, and showed no evidence of adverse next-day psychomotor or cognitive effects.

Development of l-CDB-4022 as a nonsteroidal male oral contraceptive: induction and recovery from severe oligospermia in the adult male cynomolgus monkey (Macaca fascicularis)

The present study was undertaken to examine the antispermatogenic effect of l-CDB-4022 in the adult male cynomolgus monkey. Monkeys (four per group) were dosed via nasogastric tube for 7 d with l-CDB-4022 at 12.5 mg/kg.d or vehicle (d 0=first day of dosing). Plasma levels of l-CDB-4022 and its deesterified metabolite were nondetectable prior to treatment and in all vehicle-treated monkeys. Peak levels of l-CDB-4022 and its metabolite were observed at 4 h after dosing with steady-state levels apparent around d 4. Sperm concentration and total sperm per ejaculate were decreased to levels below 1x10(6) sperm/ml or sperm/ejaculate in l-CDB-4022-treated monkeys by d 17 and remained suppressed through wk 6. Sperm motility also declined to 0% for 6 wk. Testicular volume was reduced in l-CDB-4022-treated monkeys through d 21. The left testis and epididymis were removed from all monkeys on d 24. At this time, the most mature germ cells in the seminiferous tubules of testes from l-CDB-4022-treated monkeys were either spermatocytes or round spermatids. Immature germ cells, but not mature sperm, were found in the efferent ducts and collapsed epididymal lumen of l-CDB-4022-treated monkeys. A steady recovery in sperm motility, concentration, and total sperm per ejaculate was observed in l-CDB-4022-treated monkeys such that these parameters were not different from those of vehicle-treated monkeys by wk 16. Volume of the remaining testis increased in vehicle- and l-CDB-4022-treated monkeys after hemicastration; however, the increase in l-CDB-4022-treated monkeys was delayed compared with that observed in the vehicle-treated monkeys. The morphology of the remaining testis and epididymis, which were removed on wk 17, was normal. Serum inhibin B levels were increased in l-CDB-4022-treated monkeys during the dosing interval; thereafter serum inhibin B levels declined such that there was no difference between the groups by wk 3. l-CDB-4022 treatment did not affect circulating levels of testosterone, LH, FSH, or estradiol. In conclusion, these data indicate that in the cynomolgus monkey, a representative higher primate, l-CDB-4022 exerts a selective antispermatogenic action, which was reversible under the conditions of this study and thus has potential as a nonhormonal oral male contraceptive.

Ramelteon: a novel treatment for the treatment of insomnia

Ramelteon, a potent agonist for the melatonin MT1 and MT2 brain receptors, has recently been granted approval by the US FDA for the treatment of insomnia associated with sleep onset. The drug has not exhibited potential for abuse or dependency in laboratory tests, nor does it interact with neurotransmitter receptors most associated with these phenomena, hence it has the great advantage of being a nonscheduled drug. Few data have been published in peer-reviewed journals describing its efficacy and side effects in patients with insomnia; however, side effects noted to date appear minor. No comparison study has been performed to determine whether the recommended dose of ramelteon 8 mg has any advantage over physiologic doses of melatonin (0.3 mg), particularly for long-term use.

Searching for new options for treating insomnia: are melatonin and ramelteon beneficial?

Insomnia is one of the most common complaints faced in clinical practice. The limited pharmacological options available make the treatment of this complaint a challenge. All of the available benzodiazepines and non-benzodiazepine hypnotics have the potential to induce addiction, cause withdrawal symptoms, or trigger rebound insomnia. Further, the evidence supporting the utility of commonly prescribed options such as antidepressants and antipsychotics is limited. Melatonin is a hormone that has been associated with soporific effects. Based on this premise, a melatonin receptor agonist was created. Ramelteon was approved by the Food and Drug Administration in 2005 and is the only medication indicated for the long-term treatment of insomnia. A critical review with a clinical perspective of randomized, placebo-controlled clinical trials was conducted to determine the efficacy of melatonin and ramelteon for the treatment of insomnia. Based on this review, it appears that more placebo-controlled trials are indicated before valid judgments concerning the efficacy of both melatonin and ramelteon can be made. In the meantime, there is some support for the use of melatonin for the treatment of insomnia, and findings concerning ramelteon also appear promising. Nevertheless, clinicians who prescribe melatonin or ramelteon should be cautious and carefully monitor both potential benefits and adverse effects, since data on melatonin are based on studies with multiple limitations and only three controlled trials have been done with ramelteon.

Pharmacokinetics of valerenic acid after administration of valerian in healthy subjects

OBJECTIVES

To describe the pharmacokinetics of valerenic acid in a group of healthy adults after a single oral dose of valerian using a newly developed sensitive assay for serum concentrations of valerenic acid, a commonly used marker for qualitative and quantitative analysis of valerian root and valerian products.

STUDY DESIGN

Six healthy adults (22-61 years, five men, one female) received a single 600 mg dose of valerian at 08:00. Blood samples were collected for 8 h after administration. Valerenic acid was extracted from serum and measured using a LC/MS/MS method developed in our laboratory.

RESULTS

The maximum serum concentration of valerenic acid for five of the six subjects occurred between 1 and 2 h ranging from 0.9 to 2.3 ng/mL. Valerenic acid serum concentrations were measurable for at least 5 h after the valerian dose. One subject showed a peak plasma value at 1 h and a second peak at 5 h. The elimination half-life (T(1/2)) for valerenic acid was 1.1 +/- 0.6 h. The area under the concentration time curve (AUC) as a measure of valerenic acid exposure was variable (4.80 +/- 2.96 microg/mL. h) and not correlated with subject's age or weight.

CONCLUSIONS

Assuming that valerenic acid serum concentrations correlate with the pharmacological activity of valerian, the timing of the valerenic acid peak concentration is consistent with the standard dosage recommendation to take valerian 30 min to 2 h before bedtime. Ongoing studies are evaluating the relationship between valerenic acid serum concentrations and objective measures of sleep in patients.

Ramelteon

Ramelteon, approved in the US for the treatment of insomnia characterised by difficulty with sleep onset, is a highly selective agonist for the melatonin MT1/MT2 receptors, which are believed to mediate the circadian rhythm in mammals. Ramelteon has negligible affinity for the MT3 binding sites and other receptors in the brain, including the opiate, dopamine, benzodiazepine and serotonin receptors, which may explain the lack of significant adverse events and lack of abuse or dependence potential observed with ramelteon. In three clinical trials in patients with chronic insomnia, ramelteon 8mg was effective in reducing sleep latency, without being associated with any significant or clinically relevant residual effects. It also generally increased total sleep time and, where assessed, sleep efficiency. In a first-night-effect model of transient insomnia, ramelteon 8mg was significantly more effective than placebo at reducing sleep latency and increasing total sleep time. Ramelteon was generally well tolerated; the most commonly reported adverse events occurring in more ramelteon than placebo recipients were somnolence (5% vs 3%), fatigue (4% vs 2%) and dizziness (5% vs 3%). Adverse events were mostly mild or moderate in nature. Ramelteon has been shown to have no potential for abuse or dependence.

An efficacy, safety, and dose-response study of Ramelteon in patients with chronic primary insomnia

BACKGROUND AND PURPOSE

To evaluate the efficacy, safety, and dose response of Ramelteon, a novel highly selective MT1/MT2 receptor agonist, in patients with chronic primary insomnia.

PATIENTS AND METHODS

A randomized, multicenter, double-blind, placebo-controlled, five-period crossover study design was performed. A total of 107 patients, aged 18-64 years, were randomized into a dosing sequence that included 4, 8, 16, and 32 mg of Ramelteon and placebo. Patients received all five treatments, with a 5- to 12-day washout period between treatments, and served as their own controls. Medication was administered 30 min before habitual bedtime and polysomnographic monitoring. Next-day residual effects were assessed with two visual analog scales (mood and feeling), digit symbol substitution test (DSST), word-list memory tests (immediate recall and delayed recall), and a post-sleep questionnaire that ascertained patients' alertness and ability to concentrate.

RESULTS

All tested doses of Ramelteon resulted in statistically significant reductions in latency to persistent sleep (LPS) and increases in total sleep time (TST). No next-day residual effects were apparent at any dose, as compared with placebo. There were no differences in the number or type of adverse events between any active treatment and placebo group. The most commonly reported adverse events were headache, somnolence, and sore throat.

CONCLUSIONS

Ramelteon demonstrated a statistically significant reduction in LPS and a statistically significant increase in TST, with no apparent next-day residual effects, in patients with chronic primary insomnia.

In situ poly(urea-formaldehyde) microencapsulation of dicyclopentadiene

Microencapsulated healing agents that possess adequate strength, long shelf-life and excellent bonding to the host material are required for self-healing materials. Urea-formaldehyde microcapsules containing dicyclopentadiene were prepared by in situ polymerization in an oil-in-water emulsion that meet these requirements for self-healing epoxy. Microcapsules of 10-1000 microm in diameter were produced by appropriate selection of agitation rate in the range of 200-2000 rpm. A linear relation exists between log(mean diameter) and log(agitation rate). Surface morphology and shell wall thickness were investigated by optical and electron microscopy. Microcapsules are composed of a smooth 160-220 nm inner membrane and a rough, porous outer surface of agglomerated urea-formaldehyde nanoparticles. Surface morphology is influenced by pH of the reacting emulsion and interfacial surface area at the core-water interface. High yields (80-90%) of a free flowing powder of spherical microcapsules were produced with a fill content of 83-92 wt% as determined by CHN analysis.

Cancer chemotherapy by liposomal 6-[12-(dimethylamino)ethyl]aminol-3-hydroxy-7H-indeno[2,1-clquinolin-7-one dihydrochloride (TAS-103), a novel anti-cancer agent

A novel anti-tumor agent, 6-[[2-(dimethylamino)ethyl]amino]-3-hydroxy-7H-indeno[2,1-c]quinolin-7-one dihydrochloride (TAS-103), effectively inhibits both topoisomerase I and II activities. To enhance anti-tumor efficacy and to reduce the side effects of the agent, liposomalization of TAS-103 was performed. TAS-103 was effectively entrapped in liposomes by a remote-loading method, and was stable at 4 degrees C and in the presence of 50% serum. To evaluate the anti-tumor efficacy of liposomal TAS-103, the growth inhibition against Lewis lung carcinoma cells in vitro and the therapeutic efficacy against solid tumor-bearing mice in vivo were examined. Liposomal TAS-103 showed strong cytotoxic effect against Lewis lung carcinoma cells in a dose dependent manner and effectively suppressed solid tumor growth accompanying longer survival time of tumor-bearing mice in comparison with the mice treated with free TAS-103. These results suggest that liposomal TAS-103 is useful for cancer therapy.

Metabolism and urinary excretion of a new quinoline anticancer drug, TAS-103, in humans

1. TAS-103, a novel condensed quinoline derivative, has been developed as an anticancer drug targeting topoisomerases I and II. 2. The purpose of the present study was to characterize the metabolism and urinary excretion of TAS-103 after the intravenous infusion of a single dose to patients in Phase I clinical trials. 3. Five metabolites were detected using high-performance liquid chromatography (HPLC) photodiode array and a precursor scan by liquid chromatography mass spectrometry mass spectrometry (LC/MS/MS). 4. Structures of the five metabolites were determined using the results of enzymatic hydrolysis and the analysis of production mass spectra obtained by LC/MS/MS, and by comparing HPLC retention times and UV, mass and production mass spectra of authentic standards. 5. The metabolites were identified as demethyl-TAS-103 glucuronide (DM-TAS-103-G), TAS-103 glucuronide (TAS-103-G), TAS-103 glucuronide N-oxide (NO-TAS-103-G), demethyl-TAS-103 (DM-TAS-103) and TAS-103 N-oxide (NO-TAS-103). 6. The mean total amount of TAS-103 and TAS-103-G in urine was only 6.03% of the dose, suggesting that urine is not the main elimination route. TAS-103 was extensively metabolized, and a small percentage of the parent drug (0.41%) was found in urine.

In vitro antitumor activity of TAS-103 against freshly-isolated human colorectal cancer

DNA topoisomerases (Topo) are enzymes that relieve the secondary twist on the DNA strand in the process of DNA synthesis and transcription; therefore they are unique targeting molecules for the chemotherapy of colorectal cancer. TAS-103 (6-[[2-(dimethylamino)ethyl]amino]-3-hydroxy-7H-in-deno [2,1-c]quinolin-7-one dihydrochloride, MW; 406.31), a novel quinoline derivative, has recently been established as a Topo I and Topo II inhibitor. The aim of the present study was to investigate the antitumor activity of TAS-103 by the MTT assay in human highly-purified and freshly-isolated colorectal cancer cells. To our knowledge, this is the first data concerning the antitumor activity of TAS-103 in highly-purified and isolated human colorectal cancer cells. TAS-103 showed the strongest antitumor activity among the conventional anticancer agents for colorectal cancer (p<0.05). The combination with CDDP augmented the antitumor activity of TAS-103 (p<0.05), indicating that CDDP is one of the most potent candidates to be used in combination with TAS-103. To predict the clinical effect of TAS-103, the expressions of Topo I and Topo II were measured by quantitative PCR. However, a correlation between the expression of Topo and the antitumor activity of TAS-103 was not established. In conclusion, according to this data, TAS-103 may be useful in the chemotherapy of colorectal cancer.

Phase I clinical and pharmacogenetic study of weekly TAS-103 in patients with advanced cancer

PURPOSE

TAS-103 is an inhibitor of both topoisomerase I and II enzymes with broad antitumor activity. It is metabolized to TAS-103-glucuronide (TAS-103-G) predominantly by uridine diphosphate glucuronosyltransferase isoform 1A1 (UGT1A1). We conducted a phase I study to determine the maximum-tolerated dose (MTD) and dose-limiting toxicity (DLT) of TAS-103 when administered on a weekly schedule to patients with advanced cancer. In addition, we evaluated the influence of UGT1A1 genotype on the pharmacokinetics and toxicity of TAS-103.

PATIENTS AND METHODS

Thirty-two patients were treated with escalating doses (50 to 200 mg/m(2)) of TAS-103, administered intravenously over 1 hour each week for 3 weeks. Pharmacokinetic analysis was performed at the 130-, 160-, and 200-mg/m(2) dose levels. UGT1A1 genotypes were determined using reverse-transcription polymerase chain reaction techniques.

RESULTS

DLT (grade 3 neutropenia) was observed in 5 of 12 patients at 160 mg/m(2) and in 3 of 6 patients at 200 mg/m(2). At 160 mg/m(2), there was a significant correlation between areas under the curve (AUCs) for TAS-103 and TAS-103-G (r = 0.76, P <.05) and an apparent relationship between TAS-103 AUC and D 15 absolute neutrophil count (r = -0.63, P <.05, n = 11, one outlier excluded). UGT1A1 genotype did not influence clearance of TAS-103.

CONCLUSION

We recommend a dose of 130 to 160 mg/m(2), or 250 to 300 mg administered using the above weekly schedule for phase II studies. Further studies to characterize the pharmacodynamics and pharmacogenetics of TAS-103 are warranted.

Concentration-dependent actions of a new indene derivative, TN-871, in the enteric nervous system

Intracellular electrical recordings and fluorimetric measurement of intracellular Ca2+ concentration ([Ca2+]i) were made from enteric neurons of the guinea-pig myenteric and submucosal plexuses to examine the actions of 2-n-butyl-1-(4-methylpiperazinyl)5,6-ethylendioxyindene x 2HCl (TN-871) on neural activity in the single cell. TN-871 affected neuronal electrophysiological properties and synaptic transmission in the enteric nervous system in a concentration-dependent manner; TN-871 at lower concentrations hyperpolarized enteric neurons and/or facilitated synaptic transmission, whereas at higher concentrations it depolarized enteric neurons and/or inhibited synaptic transmission. Experiments with fura-2 showed that TN-871 modulated both resting [Ca2+]i and [Ca2+]i-transient associated with action potentials. Thus, the present results demonstrated that TN-871 at lower concentrations facilitates but at higher concentrations depresses Ca2+-dependent or Ca2+-involving processes, suggesting that TN-871 may affect the Ca2+ dynamics in enteric neurons either directly, indirectly or both.

Antitumor activity of a novel quinoline derivative, TAS-103, with inhibitory effects on topoisomerases I and II

A novel quinoline derivative, TAS-103 (6-[[2-(dimethylamino)ethyl]amino]-3-hydroxy-7H-indeno[2,1-c]quinolin -7-one dihydrochloride), was developed as an anticancer agent targeting topoisomerases (topo) I and II, with marked efficacy in solid tumors. TAS-103 inhibited topo I and II (IC50: 2 microM, 6.5 microM) at a concentration similar to or lower than those of previous agents, and had a strong cytotoxic effect on P388 and KB cells (IC50: 0.0011 microM, 0.0096 microM). TAS-103 stabilized topo I and II-DNA cleavable complexes in KB cells, generating a similar amount of topo II-DNA complex to that induced by etoposide (VP-16) but a smaller amount of topo I-DNA complex than that produced by camptothecin (CPT). In the in vivo study, intermittent i.v. administration was markedly effective against s.c.-implanted murine tumors. Furthermore, TAS-103 had marked efficacy against various lung metastatic tumors, and a broad antitumor spectrum in human tumor xenografts (derived from lung, colon, stomach, breast, and pancreatic cancer). The efficacy of TAS-103 was generally greater than that of irinotecan (CPT-11), VP-16, or cis-diamminedichloroplatinum (CDDP).

Local inhibition of sebaceous gland growth by topically applied RU 58841

The biological activity of a series of nonsteroidal, pure androgen receptor inhibitors was compared using the Syrian hamster ear skin sebaceous gland model. RU 58841, RU 56187, RU 38882 and cyproterone acetate were applied topically for 4 weeks on the ventral ear pinna of sexually mature male Syrian hamsters. Their order of efficacy was as follows: RU 58841 > RU 56187 > RU 38882 > cyproterone acetate. Maximal reduction of 60% in the size of the sebaceous glands was observed in hamsters treated with RU 58841 at a dose of 10 micrograms per day. This degree of inhibition occurred without any systemic side effects as shown by the absence of inhibition on the contralateral untreated ear pinna. Longer treatment did not produce greater inhibition since extending the treatment period from 4 weeks to 12 weeks showed similar data. The effect of RU 58841 was reversible since the inhibited sebaceous glands returned to normal size within 4 weeks after the cessation of the topical applications. The potent localized inhibition of sebaceous glands by RU 58841 demonstrates the excellent potential of this compound as a topical drug for the treatment of acne and other androgen-mediated disorders.

[Chronology of regression of hypertensive ventricular hypertrophy during antihypertensive therapy with beta blockers]

To define the time course of regression of left ventricular hypertrophy (LVH) during antihypertensive therapy with beta-blocking agents, 73 hypertensive patients were serially studied by echocardiography during 12-months therapy with beta-blockers. Blood pressure decreased significantly after 1 month and further on after 12 months (from 164 +/- 18/110 +/- 9 to 139 +/- 14/94 +/- 7 mmHg, p < 0.001). Left ventricular (LV) end-diastolic dimension increased significantly after 1 month (from 51.2 +/- 3.9 to 52.2 +/- 4.7 mm, p < 0.01) and decreased after 12 months (50.4 +/- 4.0 mm, p < 0.05). Septal and posterior wall thickness decreased progressively after 1 month and 3 months, respectively. LV mass index decreased significantly after 3 months, and further on after 12 months (from 164 +/- 42 to 145 +/- 33 g/m2, p < 0.001). LV fractional shortening did not significantly change throughout the study. Thus, a reduction of hypertensive LVH occurred after 3 months of therapy with beta-blocking agents and went on during the subsequent months without impairment of LV systolic function.

High performance liquid chromatography and pharmacokinetics of the non-steroidal anti-inflammatory drug oxindanac in calves

A high-performance liquid chromatographic method for the determination of the non-steroidal anti-inflammatory drug, oxindanac, in calf plasma is described. Recoveries over the concentration range 0.375 to 62.5 micrograms/ml were 90.2-107.8% with interassay coefficients of variation of 2.1-22.3%. The limit of detection was estimated as 0.10 micrograms/ml and the limit of quantification calculated to be 0.24 micrograms/ml in a 1 ml plasma sample. This method was used to establish the pharmacokinetics following intravenous (i.v.), intramuscular (i.m.) and oral (p.o.) administration to calves of oxindanac at a dose rate of 2 mg/kg. The elimination t1/2 was long (t1/2 21.2 h after i.v. injection) and absorption was rapid (t1/2a 0.072 h) and complete (F > 100%) following i.m. administration. Bioavailability was incomplete (F = 66.6%) following p.o. administration to calves that had been fed on milk, and Wagner-Nelson analysis revealed two absorption phases (t1/2's 0.20 and 1.9 h). Oxindanac produced long-lasting inhibition of serum TxB2 production, with mean Emax values (% inhibition) of 96.8, 94.1 and 81.3 following i.v., i.m. and p.o. administration, respectively. A single i.v. or i.m. injection of 2 mg/kg oxindanac will probably be active in calves for at least 36-48 h.

Bidirectional chiral inversion of the enantiomers of the nonsteroidal antiinflammatory drug oxindanac in dogs

The nonsteroidal antiinflammatory drug oxindanac exists as two enantiomers, with most of its pharmacological activity residing in the (S)-isomer. The behavior of its enantiomers was investigated in dogs. Bidirectional inversion occurred in heparinised plasma and blood, with a ratio of enantiomers [S:R] of 7.3:1 being achieved at equilibrium after incubation for 24 h at 37 degrees C. There was no detectable inversion of either isomer in plasma incubated at 4 degrees C for up to 8 h or in aqueous solution at 37 degrees C for up to 36 h. Bidirectional inversion also occurred in vivo, with a ratio of plasma AUC (0 infinity)s [S:R] of 8.1:1. The ratio of enantiomers reached equilibrium within 2 hr following (S)- or rac-oxindanac, and within 8 h following (R)-oxindanac. Elimination t1/2s of the isomers were the same (R, 12.1 h, S, 13.3 h). There were no differences in the ratio of enantiomers following oral or intravenous application, suggesting that a systemic site for inversion was predominant. Although concentrations of the respective isomers were similar at equilibrium following administration of either (R)-, (S)-, or rac-oxindanac, AUC (0 infinity)s differed due to the delay in reaching equilibrium. The extent of inversion to the (S)-isomer was 100, 73.2, and 60.7% after administration of (S)-, rac-, and (R)-oxindanac, respectively. Although pharmacological activity might be equivalent at equilibrium following administration of either (R)-, (S)-, or rac-oxindanac; efficacy at early time points should be superior in the order (S) > racemate > (R).(ABSTRACT TRUNCATED AT 250 WORDS)

The use of intradermal carrageenan in calves to estimate the dose of oxindanac, a nonsteroidal anti-inflammatory drug

A simple and humane model of inflammation, induced by the intradermal injection of 0.3 mL of sterile 2% carrageenan, was characterized in calves by measuring the volume of skin swelling plus histological analysis of skin biopsies. Carrageenan produced a biphasic increase in skin swelling, with an early edematous response followed by a more chronic cellular infiltrate. The swelling and sensitivity to pressure observed in the early response were suitable for testing the antiedematous and analgesic activity of a new nonsteroidal anti-inflammatory drug (NSAID), oxindanac. Pretreatment with intravenous oxindanac at doses from 0.5 to 8.0 mg/kg reduced the volume of swelling and this reached statistical significance (p < 0.05) at 2 mg/kg. The ED50 and ED90 values for inhibition of the peak swelling volume (4 h) were estimated to be 1 mg/kg and 2 mg/kg, respectively. These compare with an ED90 of 2.0 mg/kg for inhibition of serum TxB2 production, an index of platelet cyclo-oxygenase activity. The dose of oxindanac required for antiedematous activity correlated, therefore, with maximal inhibition of serum TxB2. The analgesic activity of oxindanac reached no clear maximum response, but statistically significant difference (p < 0.05) from placebo was reached with doses of 2 mg/kg and above. It is concluded that intradermal carrageenan produced a simple, humane and useful model for dose estimation of a new NSAID in calves.