Comparison of Dexmedetomidine and Midazolam in Sedation for Percutaneous Drainage of Hepatic Hydatid Cysts

OBJECTIVE

Hydatid cyst still continues to be a public health problem. The basic treatment for the disease is surgery, but ultrasound-guided percutaneous drainage has become an important treatment alternative. Agents preferred for sedation during drainage performed under local anaesthesia must also preserve respiration and hemodynamic stability while providing adequate sedation. We compared the sedative properties of midazolam, which has a short duration of action, and a selective α2 adrenergic receptor agonist, dexmedetomidine, and the intraoperative complications.

METHODS

After approval by the clinical trials ethics committee, 40 patients with similar demographic data were randomized into two groups. All patients received 10 mg metoclopramide and 45.5 mg pheniramine before the procedure. Then, midazolam (0.07 mg kg(-1) IV bolus followed by 0.01 mg kg(-1) h(-1) infusion) was administered to Group 1, and dexmedetomidine (1 μg kg(-1) loading dose in 10 minutes, followed by 0.2 μg kg(-1) h(-1) continuous infusion) was administered to Group 2 for sedation. Just before the surgical procedure, all patients received IV propofol in a subhypnotic dose of 0.5 mg kg(-1); the dose was repeated if adequate sedation could not be achieved. Observer's assessment of alertness/sedation (OAA/S) scale and Bispectral index (BIS) were used to evaluate the sedation level during the procedure. Heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), peripheral oxygen saturation (SpO2) and end-tidal carbon dioxide pressure (ETCO2) were monitored before and after induction and every 5 minutes thereafter. Propofol requirement was noted for each group.

RESULTS

Sedation in the dexmedetomidine group was as effective and adequate as that observed in the midazolam group. BIS values were significantly lower in the dexmedetomidine group, especially after 10 minutes and thereafter. RR, SpO2, and ETCO2 were similar in both groups, whereas clinically insignificant decreases in HR and MAP were observed in the dexmedetomidine group. Propofol requirements were similar in both groups.

CONCLUSION

We conclude that dexmedetomidine, providing adequate sedation without respiratory depression, can be considered as an appropriate agent for sedation in surgical procedures performed under local anaesthesia.

Bispectral index score and observer's assessment of awareness/sedation score may manifest divergence during onset of sedation: Study with midazolam and propofol

Background:

Correlation between the clinical and electroencephalogram-based monitoring has been documented sporadically during the onset of sedation. Propofol and midazolam have been studied individually using the observer's assessment of awareness/sedation (OAA/S) score and Bispectral index score (BIS). The present study was designed to compare the time to onset of sedation for propofol and midazolam using both BIS and OAA/S scores, and to find out any correlation.

Methods:

A total of 46 patients (18-60 years, either sex, American Society of Anesthesiologists (ASA) I/II) posted for infraumbilical surgeries under spinal anaesthesia were randomly allocated to receive either injection propofol 1 mg/kg bolus followed by infusion 3 mg/kg/h (Group P, n=23) or injection midazolam 0.05 mg/kg bolus followed by infusion 0.06 mg/kg/h (Group M, n=23). Spinal anaesthesia was given with 2.5 ml to 3.0 ml of 0.5% bupivacaine heavy. When sensory block reached T6 level, sedation was initiated. The time to reach BIS score 70 and time to achieve OAA/S score 3 from the start of study drug were noted. OAA/S score at BIS score 70 was noted. Data from 43 patients were analyzed using SPSS 12 for Windows.

Results:

Time to reach BIS score 70 using propofol was significantly lower than using the midazolam (P<0.05). Time to achieve OAA/S score 3 using propofol was comparable with midazolam (P=0.358).

Conclusion:

A divergence exists between the time to reach BIS score 70 and time to achieve OAA/S score 3 using midazolam, compared with propofol, during the onset of sedation.

Effect of moxidectin on CYP3A4 activity as evaluated by oral midazolam pharmacokinetics in healthy subjects

In order to evaluate the potential for CYP3A4 induction by moxidectin, midazolam pharmacokinetic (PK) parameters were compared before and after moxidectin administration. Healthy subjects received a single 8 mg dose of moxidectin and 3 single 7.5 mg doses of midazolam 3 days before, and 7 and 89 days after the moxidectin. Blood samples were taken for 24 hours to measure midazolam and metabolites in plasma, and for 89 days to measure moxidectin in plasma after dose administration. Noncompartmental PK analyses were performed for each analyte. Analysis of variance was performed on log-transformed midazolam parameters with treatment day as a fixed effect. Adverse events were recorded and laboratory tests, physical examinations, pulse oximetry monitoring, vital sign measurement, and electrocardiograms performed. Thirty-nine subjects were enrolled in the study; PK data were available for 37 subjects. Moxidectin PK parameters were similar to previous studies. There were no significant changes in PK for midazolam or its metabolites 7 or 89 days after moxidectin administration. Adverse events were generally mild and there were no relevant changes in safety assessments. Thus, 8 mg moxidectin does not induce CYP3A4 activity and other CYP3A4 substrates are unlikely to be affected by moxidectin co-administration.

Effects of dexmedetomidine and xylazine on cardiovascular function during total intravenous anaesthesia with midazolam and ketamine and recovery quality and duration in horses

OBJECTIVES

To compare cardiovascular effects and recovery quality and duration of total intravenous anaesthesia (TIVA) with xylazine-ketamine-midazolam or dexmedetomidine-ketamine-midazolam.

STUDY DESIGN

Prospective, randomized experimental cross-over trial.

ANIMALS

Eight adult warmblood horses.

METHODS

After sedation with acepromazine and either xylazine [0.5 mg kg(-1) , intravenously (IV)] or dexmedetomidine (3.5 μg kg(-1) IV) anaesthesia was induced with ketamine and midazolam and maintained with a constant rate infusion (CRI) of xylazine (1 mg kg(-1)  hour(-1) ) [XKM] or dexmedetomidine (7 μg kg(-1)  hour(-1) ) [DKM] in combination with midazolam (0.1 mg kg(-1)  hour(-1) ), and ketamine infusion (initially 3 mg kg(-1)  hour(-1) ) for 120 minutes. Ketamine infusion rate was increased in response to positive reactions to electrical nociceptive stimulation performed every 30 minutes. Heart rate (HR), mean arterial blood pressure (MAP) and cardiac output (Q˙t) were measured before treatment (baseline), after sedation (not Q˙t), and during anaesthesia. Xylazine, dexmedetomidine, midazolam and ketamine kinetics were calculated, from plasma drug concentrations. Twenty minutes after end of TIVA, flumazenil (0.01 mg kg(-1) IV) was administered. Recovery quality and duration were assessed. Two-way analysis of variance with repeated measurements or Wilcoxon signed rank test as relevant were used to analyse data with an alpha of 5%.

RESULTS

Compared to baseline, MAP did not change, while similar, but limited, decreases in HR and Q˙t were observed in both TIVA's. Mean ketamine doses of 3.7 mg kg(-1)  hour(-1) were required with both treatments. Plasma concentrations of dexmedetomidine and xylazine showed high intra- and inter-individual changes with elimination half-lifes of 46 ± 7 minutes and 64 ± 13 minutes, respectively. Recovery quality was good to excellent with mean duration of 37 ± 16 and 46 ± 21 minutes after stopping TIVA with XKM and DKM, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Both drug combinations are suitable to maintain anaesthesia for two hours, with good cardiovascular and good to excellent recovery conditions.

Prophylactic midazolam and clonidine for emergence from agitation in children after emergence from sevoflurane anesthesia: a meta-analysis

BACKGROUND

Emergence agitation (EA) after emergence from sevoflurane anesthesia is a common phenomenon in children. The efficacy of prophylactic midazolam or clonidine in preventing EA is controversial.

OBJECTIVE

We performed a meta-analysis of clinical trials of the 2 drugs to evaluate their ability to prevent EA in pediatric patients after emergence from sevoflurane anesthesia.

METHODS

A comprehensive literature search was conducted to identify clinical trials that observed the effect of midazolam and clonidine on preventing EA in children after their emergence from sevoflurane anesthesia. All data were examined using the Mantel-Haenszel model to calculate the pooled odds ratio (OR) and 95% CI. I(2) was used to assess heterogeneity. Subgroup analysis was used to assess the effects of preoperative analgesics, routes of administration, and dose, and funnel plots were used to check publication bias.

RESULTS

After a comprehensive literature search, we found 12 papers that met the criteria for inclusion in this analysis, with a total of 447 children in the midazolam group and 767 children in the clonidine group. We found that both midazolam and clonidine decreased the incidence of EA (OR = 0.45 [95% CI, 0.29-0.70], P = 0.0004, I(2) = 46%; and OR = 0.24 [95% CI, 0.13-0.43], P < 0.00001, I(2) = 48%, respectively). Subgroup analysis indicated that preoperative analgesia may decrease the effect of midazolam against EA, whereas for clonidine, neither the route of administration (intravenous or caudal) nor the dose affected the results. Funnel plots did not detect publication bias in the midazolam group, but a bias was detected in the clonidine group.

CONCLUSIONS

This meta-analysis suggests that prophylactic administration of midazolam or clonidine could significantly decrease the incidence of sevoflurane-induced EA in pediatric patients.

Comparison of biochemical stress indicators in juvenile captive estuarine crocodiles (Crocodylus porosus) following physical restraint or chemical restraint by midazolam injection

Using a prospective, randomized study design we demonstrate that midazolam sedation minimizes acidosis compared with physical restraint in captive juvenile estuarine crocodiles during handling or noninvasive procedures at preferred body temperature. A dose of midazolam (5.0 mg/kg) was administered intramuscularly into the forelimb of 20 male estuarine crocodiles weighing 2-3.5 kg. Their heart and respiratory rate and degree of sedation were monitored until recovery and then daily for 7 subsequent days. Blood samples were taken at 30, 60, 90, 180, and 360 min. We recorded lactate, partial pressure of carbon dioxide (CO2), hematocrit, glucose, and blood pH. A second group (1.9-2.6 kg) was physically restrained for 5 min and the same parameters recorded. Physically restrained animals demonstrated elevated heart rate, respiratory rate, glucose, lactate, and anion gap compared with the midazolam-treated group. Physically restrained animals had lower pH, bicarbonate, and partial pressure of CO2 compared with the midazolam-treated group. Behavior in the physically restrained group in the days following the study was disrupted, with reluctance to feed and bask, compared with midazolam-treated animals whose behavior was normal. We conclude that midazolam administered in the forelimb of captive estuarine crocodiles of 2-3.5 kg provides predictable onset and duration of sedation enabling physical examination, sample collection, and translocation of the animals with minimal disturbance to lactate, pH, and CO2. Behavior following recovery appears normal.

Midazolam induces cellular apoptosis in human cancer cells and inhibits tumor growth in xenograft mice

Midazolam is a widely used anesthetic of the benzodiazepine class that has shown cytotoxicity and apoptosisinducing activity in neuronal cells and lymphocytes. This study aims to evaluate the effect of midazolam on growth of K562 human leukemia cells and HT29 colon cancer cells. The in vivo effect of midazolam was investigated in BALB/c-nu mice bearing K562 and HT29 cells human tumor xenografts. The results show that midazolam decreased the viability of K562 and HT29 cells by inducing apoptosis and S phase cell-cycle arrest in a concentration-dependent manner. Midazolam activated caspase-9, capspase-3 and PARP indicating induction of the mitochondrial intrinsic pathway of apoptosis. Midazolam lowered mitochondrial membrane potential and increased apoptotic DNA fragmentation. Midazolam showed reactive oxygen species (ROS) scavenging activity through inhibition of NADPH oxidase 2 (Nox2) enzyme activity in K562 cells. Midazolam caused inhibition of pERK1/2 signaling which led to inhibition of the anti-apoptotic proteins Bcl-XL and XIAP and phosphorylation activation of the pro-apoptotic protein Bid. Midazolam inhibited growth of HT29 tumors in xenograft mice. Collectively our results demonstrate that midazolam caused growth inhibition of cancer cells via activation of the mitochondrial intrinsic pathway of apoptosis and inhibited HT29 tumor growth in xenograft mice. The mechanism underlying these effects of midazolam might be suppression of ROS production leading to modulation of apoptosis and growth regulatory proteins. These findings present possible clinical implications of midazolam as an anesthetic to relieve pain during in vivo anticancer drug delivery and to enhance anticancer efficacy through its ROS-scavenging and pro-apoptotic properties.

Reduced exposure variability of the CYP3A substrate simvastatin by dose individualization to CYP3A activity

This study aimed to demonstrate that the dose of a CYP3A substrate (simvastatin) can be adapted individually on the basis of CYP3A activity as assessed by midazolam metabolic clearance. In 18 healthy participants individual CYP3A activity was quantified using midazolam metabolic clearance both alone and during CYP3A inhibition with 40 mg ritonavir. Thereafter, simvastatin acid exposure was determined after a simvastatin standard dose (40 mg) and doses adapted to individual CYP3A activity at baseline and during CYP3A inhibition. Interindividual variability of CYP3A activity and simvastatin acid AUC0-24 was large and both correlated (r(2)  = 0.745, P < .001). The adapted simvastatin doses ranged from 25 to 80 mg and their administration reduced simvastatin variability fivefold. Despite the low adapted simvastatin dose of 12 mg during CYP3A inhibition with ritonavir, exposure increased (point estimate of 4.2 [90% CI: 3.15-5.61]) probably caused by additional OATP1B1 inhibition. CYP3A activity-based dose adaptation can be used to reduce interindividual variability in simvastatin exposure.

Assessing the sedative effect of oral vs submucosal meperidine in pediatric dental patients

BACKGROUND

THE GOAL OF THIS INVESTIGATION WAS TO COMPARE THE BEHAVIORAL AND PHYSIOLOGICAL EFFECTS OF THREE SEDATIVE DRUG REGIMENS: oral meperidine (OM), submucosal meperidine (SM) and oral midazolam (M) in healthy pediatric patients.

MATERIALS AND METHODS

This study sample consisted of thirty children aged 24-72 months (mean = 41.1) exhibiting definitely negative behavior. Three sedative regimens including: Oral meperidine/hydroxyzine, oral midazolam/hydroxyzine and submucosal meperidine/oral hydroxyzine were administered randomly during three consecutive appointments with a crossover design. Houpt behavioral scale was employed for evaluating the sedation effect of each regimen by a calibrated independent Pediatric dentist. Physiologic parameters were also recorded including blood oxygen saturation and pulse rate. Data was analyzed using Wilcoxon-signed ranked test, Mc-Nemar, GEE Logistic regression, Friedman, Fisher exact and Cochran tests for significance.

RESULTS

Overall success rates were 50%, 46.7% and 26.7% for submucosal meperidine, oral meperidine and oral midazolam, respectively (P = 0.03). The probability of achieving a success in behavior control was more in 48-72 month olds. Child's age and drug type were the two main predictors of altered behavior. Evaluating the differences between the effects of three tested regimens on recorded physiological parameters showed no significant differences.

CONCLUSION

All three regimens were proved safe within the limits of the current study. Meperidine sedation in both routes was considered to be more effective. Although there was less sleep and more head/oral resistance in midazolam group, the difference between groups was not significant.

Comparison of effects of ketamine, ketamine-dexmedetomidine and ketamine-midazolam on dressing changes of burn patients

Objective:

The aim of this randomized, controlled study was to compare the sedoanalgesic effects of ketamine-dexmedetomidine and ketamine-midazolam on dressing changes of burn patients.

Materials and Methods:

Following Ethics Committee approval and informed patient consent, 90 ASA physical statuses I and II adult burn patients were included in the study. Patients were randomly divided into three groups. Ten minutes before dressing change, the dexmedetomidine group (group KD) (n = 30) received a continuous infusion of dexmedetomidine at a rate of 1 μg kg^-1, the midazolam group (group KM) (n = 30) received a continuous infusion of midazolam at a rate of 0.05 mg kg^-1 and the saline group (group KS) (n = 30) received a continuous infusion of saline intravenously. One minute before dressing change, each patient was administered 1 mg kg^-1 ketamine intravenously. Hemodynamic variables, pain and sedation scores, the number of patients requiring additional ketamine, time to dressing change and recovery time were recorded.

Results:

Systolic blood pressure (SBP) values were significantly lower at, before and after ketamine administration; and 5, 10 and 15 minutes after the procedure in group KD in comparison with the other groups (P <0.05). There was no significant difference in pain scores among the groups during the study period. Sedation scores were significantly higher in group KD than in groups KM and KS at the end of the first hour (P <0.05). Time to dressing change and recovery time were similar in all the groups

Conclusion:

In burn patients undergoing dressing changes, although both combinations ketamine-dexmedetomidine and ketamine-midazolam offered an effective sedoanalgesia without causing any significant side effect, the former resulted in higher sedation and lower hemodynamic discrepancy.

Efficacy of dexmedetomidine compared with midazolam for sedation in adult intensive care patients: a systematic review

Patients in Intensive Care Unit (ICU) often require sedatives which commonly include midazolam and the more recently developed α2-receptor agonist, dexmedetomidine. It was our aim to compare the sedative and clinical effectiveness of dexmedetomidine vs midazolam in adults admitted to ICU, using an objective appraisal of randomized control trials. Medline, Embase, SCOPUS, Web of Knowledge, Cinhal, the United States National Library of Medicine, and the Cochrane Database of Systematic Reviews were searched using keywords: 'dexmedetomidine', 'midazolam', and 'intensive care'. These were limited to human studies and adults (>18 yr old). Six randomized controlled trials were found and were critically appraised using a standardized appraisal method. Two papers described the time spent by each intervention group within a specified target sedation range and both found no statistically significant difference between midazolam and dexmedetomidine (P=0.18 and P=0.15). A third paper found no statistically significant difference in the length of time that patients were sedated within a target zone (P=0.445). Two additional pilot studies did not report P values as they were insufficiently statistically powered. A final paper found that, of the eight occasions measured, patients on dexmedetomidine were more often within the target sedation range than patients on midazolam. The sedative benefits of dexmedetomidine vs midazolam remain inconclusive. While some secondary outcomes showed clinical effectiveness of dexmedetomidine, more research is needed to validate the findings of these studies.

Drug-drug interactions and metabolism in cytochrome P450 2C knockout mice: application to troleandomycin and midazolam

Drug-drug interactions (DDIs) may cause serious drug toxicity and delay development of candidate drugs. Screening using human liver microsomes and hepatocytes can help predict DDIs but do not always provide the degree of certainty required for confident progression of a candidate drug. Thus a suitable in vivo test system could be of great value. Here a Cyp2c knockout (KO) mouse was investigated for studying DDIs using midazolam (MDZ) a standard human CYP3A4 substrate and troleandomycin (TAO) a potent human CYP3A4 inhibitor. Pharmacokinetics (PK) and biotransformation of MDZ were investigated following dosing to Cyp2c KO and wild type mice before and after TAO treatment. The noteworthy differences in the metabolism of MDZ in Cyp2c KO compared to wild type mice confirms the important role that Cyp2c enzymes play in the murine metabolism of MDZ in vivo. The impact of Cyp3a inhibition produced a further increase in circulating MDZ concentrations in all individuals from both strains of mice though the impact of the elimination of the Cyp2c pathway in the KO mice on the AUC was less than perhaps expected. We have shown that TAO produces an increase in the MDZ concentration and a reduction in the 1'hydroxymidazolam/midazolam formation ratio but the expected difference in the magnitude of this effect between the wild type and the Cyp2c KO mice was not seen. The magnitude of the TAO effect was also smaller than is reported in humans. Hence further work is required before this animal model could be used to predict clinical interactions.

Inhibitory effect of midazolam on MMP-9, MMP-1 and MMP-13 expression in PMA-stimulated human chondrocytes via recovery of NF-κB signaling

INTRODUCTION

Midazolam, a benzodiazepine, has a hypnotic effect and is widely used as an intravenous sedative. Past studies have clearly established that midazolam has beneficial effects in attenuating ischemia-reperfusion injury more than other currently used sedative drugs. However, the role of midazolam on chondroprotection via inhibition of matrix metalloproteinases (MMPs) is warrant investigation. The aim of this study was to examine the mechanisms of action of midazolam on MMP expression via nuclear factor κB (NF-κB) signaling in activated chondrosarcoma cells maintained in vitro.

MATERIAL AND METHODS

Chondrocytes, SW1353 cells, were stimulated with phorbol 12-myristate 13-acetate (PMA) in the absence or presence of various concentrations of midazolam (5-20 µM). Release of MMP-9 into the culture media was determined by gelatin zymography. The expressions of MMP-1, MMP-9 and MMP-13, phosphorylation of extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinases and degradation of IκB-α were determined by western blotting assay.

RESULTS

Midazolam significantly down-regulated PMA-induced MMP-9 protein expression at concentrations of 5, 10 and 20 µM, the values were 1.95 ±0.09 (p < 0.01), 1.71 ±0.12 (p < 0.01) and 1.35 ±0.20 (p < 0.001), respectively. At concentrations of 5, 10 and 20 µM, it was significantly inhibited the PMA-induced expressions of MMP-1 (2.27 ±0.10, 1.98 ±0.11 and 1.56 ±0.15; p < 0.001) and MMP-13 (0.89 ±0.04, 0.81 ±0.07, and 0.74 ±0.09; p < 0.001), respectively. Midazolam at concentrations of 10 and 20 µM for 15 min significantly reversed the rate of degradation (0.895 ±0.051; p < 0.05 and 0.926 ±0.060; p < 0.01, respectively) of IκB-α in PMA-chondrocyte cells. In addition, this sedative drug inhibited PMA-induced levels of phos-ERK (1.243 ±0.12, 1.108 ±0.16 and 0.903 ±0.19, respectively) and phos-p38 (1.146 ±0.10, 1.063 ±0.13 and 0.946 ±0.18, at concentrations of (5, 10 and 20 µM), respectively.

CONCLUSIONS

These results are important for understanding the mechanism of midazolam in inhibiting PMA-induced MMP expression through the signaling pathways of either NF-κB or ERK/p38 MAPKs down-regulation.

Association between bispectral index and age and use of sedative drugs in high spinal anaesthesia

OBJECTIVES

A prospective, randomized, double-blind study using bispectral index values to objectively quantify the sedative effect of high spinal anaesthesia in patients stratified according to age, and to determine whether sedative drugs are associated with additional adverse respiratory and haemodynamic effects in older patients.

METHODS

Patients who were electively scheduled for lower limb or abdominal surgery were recruited and allocated into one of three groups according to their age and whether midazolam and fentanyl were used: younger (20-40 years); and older (61-80 years) with or without midazolam and fentanyl intravenous infusion.

RESULTS

The study recruited a total of 90 patients (n = 30 per group). Intraoperative bispectral index values were significantly lower than preoperative values in all groups. Patients in the older age group had significantly lower intraoperative bispectral index values than younger patients. Older patients were significantly more likely to experience respiratory depression (arterial oxyhaemoglobin saturation <90%) than younger patients.

CONCLUSIONS

The sedative effect of high spinal anaesthesia is greater in older patients than in younger patients, with an increase in respiratory instability.

A review of the practice of sedation with inhalational anaesthetics in the intensive care unit with the AnaConDa(®) device

The intensive care unit (ICU) environment is often perceived to be hostile and frightening by patients due to unfamiliar surroundings coupled with presence of numerous personnel, monitors and other equipments as well as a loss of perception of time. Mechanical ventilation and multiple painful procedures that often need to be carried out in these critically ill patients add to their overall anxiety. Sedation is therefore required not only to allay the stress and anxiety, but also to allow for mechanical ventilation and other invasive therapeutic and diagnostic procedures to be performed. The conventional intravenous sedative agents used in ICUs suffer from problems of over sedation, tachyphylaxis, drug accumulation, organ specific elimination and often lead to patient agitation on withdrawal. All this tend to prolong the ventilatory as well as ICU and hospital discharge time, which increase the risk for infection and add to the overall increase in morbidity, mortality and hospital costs. In 2005, the anaesthetic conserving device (AnaConDa(®)) was marketed for ICU sedation with volatile anaesthetic agents. A number of trials have shown the effectiveness of using volatile anaesthetic agents for ICU sedation with the AnaConDa device. Compared with intravenous sedatives, use of volatile anaesthetic agents have resulted in shorter wake up and extubation time, lesser duration of mechanical ventilation and faster discharge from hospitals. This review shall focus on the benefits, technical pre-requisites and status of sedation with volatile anaesthetic agents in ICUs with the AnaConDa(®) device.

Anesthetic drug development: Novel drugs and new approaches

The ideal sedative–hypnotic drug would be a rapidly titratable intravenous agent with a high therapeutic index and minimal side effects. The current efforts to develop such agents are primarily focused on modifying the structures of existing drugs to improve their pharmacodynamic and pharmacokinetic properties. Drugs currently under development using this rational design approach include analogues of midazolam, propofol, and etomidate, such as remimazolam, PF0713, and cyclopropyl methoxycarbonyl-etomidate (MOC-etomidate), respectively. An alternative approach involves the rapid screening of large libraries of molecules for activity in structural or phenotypic assays that approximate anesthetic and target receptor interactions. Such high-throughput screening offers the potential for identifying completely novel classes of drugs. Anesthetic drug development is experiencing a resurgence of interest because there are new demands on our clinical practice that can be met, at least in part, with better agents. The goal of this review is to provide the reader with a glimpse of the novel anesthetic drugs and new developmental approaches that lie on the horizon.

A prospective, randomized, double blind and placebo-control study comparing the additive effect of oral midazolam and clonidine for postoperative nausea and vomiting prophylaxis in granisetron premedicated patients undergoing laparoscopic cholecystecomy

Background:

Reduction of postoperative nausea and vomiting (PONV) continues to be a major challenge in perioperative care in spite of introduction of newer antiemetics with better efficacy and safety profiles. Therefore, we evaluated the additive effect of oral midazolam and clonidine for PONV prophylaxis in granisetron premedicated patients undergoing laparoscopic cholecystectomy.

Materials and Methods:

In a prospective, randomized fashion, 120 selected cases were randomized into three groups: I, II or III to receive a tablet of midazolam (15 mg, n = 36), clonidine (150 mcg, n = 40), or glucose as placebo (5 g, n = 44) orally, 1 h before anesthesia. Occurrence of PONV along with need for rescue antiemetic during the first postoperative day was compared between groups as a primary outcome.

Results:

Episodes of PONV reduced significantly in Group II (15%) as compared to group I and III (22.2%, 59%) at various time points during the period of observation (P = 0.002). Need for rescue antiemetic was significantly lower in group I (13.88%) and II (5%) as compared to group III (52.27%, P < 0.001).

Conclusion:

Oral clonidine is better adjuvant for PONV prophylaxis, as compared to midazolam, in granisetron premedicated patients undergoing laparoscopic cholecystectomy.

Pharmacological treatment of neonatal seizures: a systematic review

Pharmacologic treatment options for neonatal seizures have expanded over the past 2 decades, and there is no consensus on optimal treatment strategy. We systematically reviewed the published literature to determine which medication(s) are most effective for treating neonatal seizures, by retrieving trials and observational investigations via PubMed (through August 2011) that focused on pharmacological seizure treatment of neonates (≤ 28 days old) and utilized continuous or amplitude-integrated EEG to confirm seizure diagnosis and cessation. Our search identified 557 initial articles and 14 additional studies after reference reviews, with 16 meeting inclusion criteria. Of these, 2 were randomized trials and only 3 additional investigations included comparison groups. We found limited evidence regarding the best pharmacologic treatment for neonatal seizures, but were able to devise a treatment algorithm from available data. These findings have the potential to serve as a clinical reference and to inform the design of comparative effectiveness investigations for neonatal antiepileptics.

Comparison of sedation effectiveness of remifentanil-dexmedetomidine and remifentanil-midazolam combinations and their effects on postoperative cognitive functions in cystoscopies: A randomized clinical trial

BACKGROUND

The aim of the study is to compare the effects of remifentanil/dexmedetomidine and remifentanil/midazolam combinations in monitored anesthesia care (MAC) during cystoscopies.

MATERIALS AND METHODS

Forty patients who received remifentanil infusion of 0.05 μg kg(-1) min(-1) for cytoscopy procedure were randomized into two groups: Either dexmedetomidine 1 mg kg(-1) (Group D) or midazolam 0.2 mg kg(-1) h(-1) (Group M) was administered intravenously for the first 10 min. Subsequently, anesthesia was maintained by using the bispectral index as a continuous infusion of dexmedetomidine (0.2-0.7 μg kg(-1) h(-1)) or midazolam (0.05-0.15 μg kg(-1) h(-1)). Heart rate, mean arterial pressure, mini-mental state examination findings, levels of sedation andanalgesia, and the patient's and surgeon's satisfaction were recorded.

RESULTS

Successful sedation and analgesia were achieved in all the patients. We were able to reach the target sedation level faster in Group D (P<0.0001). In Group D, the cognitive functions were less affected than in Group M (P<0.0001). Patient's and surgeon's satisfaction were significantly higher in Group D.

CONCLUSION

The targeted sedation levels were achieved in a shorter period with dexmedetomidine-remifentanil compared to midazolam-remifentanil. The dexmedetomidine-remifentanil combination was observed to affect the cognitive functions less than midazolam-remifentanil did with shorter recovery times. Besides, patient's and surgeon's satisfaction rates were superior with dexmedetomidine-remifentanil. It was concluded that dexmedetomidine-remifentanil may be a combination of choice for monitored anesthesia care applications in outpatient surgical procedures of short duration.

Effect of a herbal extract containing curcumin and piperine on midazolam, flurbiprofen and paracetamol (acetaminophen) pharmacokinetics in healthy volunteers

AIMS

Turmeric extract derived curcuminoids (curcumin, demethoxycurcumin and bisdemethoxycurcumin) are currently being evaluated for the treatment of cancer and Alzheimer's dementia. Previous in vitro studies indicate that curcuminoids and piperine (a black pepper derivative that enhances curcuminoid bioavailability) could inhibit human CYP3A, CYP2C9, UGT and SULT dependent drug metabolism. The aim of this study was to determine whether a commercially available curcuminoid/piperine extract alters the pharmacokinetic disposition of probe drugs for these enzymes in human volunteers.

METHODS

A randomized placebo-controlled six way crossover study was conducted in eight healthy volunteers. A standardized curcuminoid/piperine preparation (4 g curcuminoids plus 24 mg piperine) or matched placebo was given orally four times over 2 days before oral administration of midazolam (CYP3A probe), flurbiprofen (CYP2C9 probe) or paracetamol (acetaminophen) (dual UGT and SULT probe). Plasma and urine concentrations of drugs, metabolites and herbals were measured by HPLC. Subject sedation and electroencephalograph effects were also measured following midazolam dosing.

RESULTS

Compared with placebo, the curcuminoid/piperine treatment produced no meaningful changes in plasma C(max), AUC, clearance, elimination half-life or metabolite levels of midazolam, flurbiprofen or paracetamol (α = 0.05, paired t-tests). There was also no effect of curcuminoid/piperine treatment on the pharmacodynamics of midazolam. Although curcuminoid and piperine concentrations were readily measured in plasma following glucuronidase/sulfatase treatment, unconjugated concentrations were consistently below the assay thresholds (0.05-0.08 μM and 0.6 μM, respectively).

CONCLUSION

The results indicate that short term use of this piperine-enhanced curcuminoid preparation is unlikely to result in a clinically significant interaction involving CYP3A, CYP2C9 or the paracetamol conjugation enzymes.

Continuous intravenous anaesthesia with sufentanil and midazolam in medetomidine premedicated New Zealand White rabbits

BACKGROUND

Anaesthesia in rabbits is associated with a high mortality rate, compared to that in cats and dogs. Total intravenous anaesthesia (TIVA) with drugs that provide cardiovascular stability and are rapidly metabolised could be of benefit for use in rabbits. The aim was to evaluate cardiorespiratory effects of TIVA with sufentanil-midazolam in eight New Zealand White rabbits. Subcutaneous premedication with medetomidine (0.1 mg/kg BW) was followed by IV administration of a mixture of 2.5 μg/mL sufentanil and 0.45 mg/mL midazolam at a rate of 0.3 mL/kg BW/h for anaesthetic induction. Additionally, intravenous boluses of 0.1 mL of the mixture were administered every 20 s until the righting reflex was lost. Following endotracheal intubation, anaesthesia was maintained for 60 min with an infusion rate adjusted to supress the pedal withdrawal reflex. Air and oxygen (1:2) were delivered at 3 L/min. Physiological variables were recorded before induction and at predefined time points during and after anaesthesia.

RESULTS

Righting and pedal withdrawal reflexes were lost within 3 and 5 min, respectively. Doses of sufentanil and midazolam were 0.48 μg/kg BW and 0.09 mg/kg BW for induction, and 0.72 μg/kg BW/h and 0.13 mg/kg BW/h for maintenance. Apnoea occurred in two rabbits. Induction of anaesthesia caused a significant increase in heart rate, cardiac output and arterial CO2 partial pressure and a decrease in mean arterial pressure, respiratory rate and pH. Mean time from stopping the infusion to endotracheal extubation was 5 min, and to return of the righting reflex 7 min. Anaesthesia was characterized by induction and recovery without excitation, with muscle relaxation, and absence of the pedal withdrawal reflex.

CONCLUSIONS

TIVA with sufentanil-midazolam provided smooth induction and recovery of anaesthesia in rabbits but with marked hypotension and respiratory depression, requiring mechanical ventilation. Further evaluation is needed to establish if the protocol is useful for rabbits undergoing surgery.

Inhibition of cancer cell proliferation by midazolam by targeting transient receptor potential melastatin 7

Transient receptor potential melastatin 7 (TRPM7), a Ca²⁺-permeable channel, has been demonstrated to be present in cancer cells and involved in their growth and proliferation. The present study used midazolam, a benzodiazepine class anesthesic, to pharmacologically intervene in the expression of TRPM7 and to inhibit cancer cell proliferation. Midazolam significantly inhibited the growth and proliferation of FaDu human hypopharyngeal squamous cell carcinoma cells, concurring with the induction of G₀/G₁ cell cycle arrest and blockage of Rb activation. Central-type and peripheral-type benzodiazepine receptor antagonists did not abrogate proliferation inhibition by midazolam, while the specific TRPM7 agonist bradykinin reversed this effect. In addition, other benzodiazepines, diazepam and clonazepam also exhibited anti-proliferative activities. The inhibitory activity on cancer cell growth and proliferation, combined with the TRPM-dependent mechanism, reveals the anticancer potential of midazolam as a TRPM7 inhibitor and supports the suggestion that TRPM7 is a valuable target for pharmaceutical intervention.

Anesthetic effects of a mixture of medetomidine, midazolam and butorphanol in two strains of mice

The combination of ketamine and xylazine is a widely used anesthetic for laboratory animals. However, due to an abuse problem in Japan, ketamine has been specified as a narcotic since 2007. Instead of using ketamine, Kawai et al. reported an injectable formula with an equivalent effect to the mixture of ketamine and xylazine [11]. The mixture of 0.3 mg/kg body weight (b.w.) medetomidine (Med.), 4.0 mg/kg b.w. midazoram (Mid.), and 5.0 mg/kg b.w. butorphanol (But.) produced an anesthetic duration of around 40 min in outbred ICR mice. However, the anesthetic effect of the mixture for inbred mice strains remains unknown. Therefore, we examined anesthetic effects of the mixture of Med., Mid., and But. in the BALB/c and C57BL/6J strains. After intraperitoneal injection into mice, right front paw, left hind paw, and tail pinch reflexes as well as corneal and righting reflexes were observed. Every 5 min, we scored each reflex category as 0 for reaction or 1 for no reaction. As long as the total score was at least 4 out of 5, we considered the mixture as putting a mouse in a surgical anesthetic state. The mixture produced an anesthetic duration of more than 45 min in both strains of mice. These results indicate that the mixture of Med., Mid., and But. can be a useful and effective anesthesia for the BALB/c and C57BL/6J strains of inbred mice as well as outbred ICR mice.

Prophylactic administration of haloperidol plus midazolam reduces postoperative nausea and vomiting better than using each drug alone in patients undergoing middle ear surgery

Aims:

The efficacy of using midazolam or haloperidol for prevention of postoperative nausea and vomiting (PONV) has been investigated before. The main object of the present study was to evaluate the anti-emetic effects of combining administration of intravenous haloperidol with intravenous midazolam on PONV in patients underwent middle ear surgery in comparison with using each drug alone.

Methods:

Study design was randomized, double-blind, placebo-controlled. 80 patients, aged 18-60 years, scheduled for middle ear surgery in Kashani Hospital Medical Center under general anesthesia were enrolled in this randomized, double-blind, placebo-controlled study. Patients were divided into 4 groups of 20 each and received haloperidol 2 mg i.v. (Group H); midazolam 2 mg i.v. (Group M); haloperidol 2 mg plus midazolam 2 mg i.v. (Group HM); saline i.v. (Group C). The incidences of PONV and complete response were evaluated at 0-2 hours after arrival to the PACU and 2-24 hours after arrival to the ward in 4 groups.

Results:

Patients in group HM had significantly lower incidence of PONV compared with groups H, M, and C throughout 0-24 h (P<00.5). The HM group had the lowest incidence of PONV (0-2, 2-24, and 0-24 h) and the highest incidence of complete response. Postoperative anti-emetic requirement was significantly less in group HM compared with group M or H (P<0.05).

Conclusion:

Combine administration of haloperidol 2 mg plus midazolam 2 mg significantly reduced PONV better than using each drug alone in patients underwent middle ear surgery under general anesthesia.

Preanesthetic medication in children: A comparison of intranasal dexmedetomidine versus oral midazolam

Background:

Relieving preoperative anxiety is an important concern for the pediatric anesthesiologist. Midazolam has become the most frequently used premedication in children. However, new drugs such as the α₂ -agonists have emerged as alternatives for premedication in pediatric anesthesia.

Methods:

One hundred and twenty children scheduled for adenotonsillectomy were enrolled in this prospective, double-blind, randomized study. The children were divided into two equal groups to receive either intranasal dexmedetomidine 1 μg/kg (group D), or oral midazolam 0.5 mg/kg (group M) at approximately 60 and 30 mins, respectively, before induction of anesthesia. Preoperative sedative effects, anxiety level changes, and the ease of child-parent separation were assessed. Also, the recovery profile and postoperative analgesic properties were assessed.

Results:

Children premedicated with intranasal dexmedetomidine achieved significantly lower sedation levels (P=0.042), lower anxiety levels (P=0.036), and easier child-parent separation (P=0.029) than children who received oral midazolam at the time of transferring the patients to the operating room. Postoperatively, the time to achieve an Aldrete score of 10 was similar in both the groups (P=0.067). Also, the number of children who required fentanyl as rescue analgesia medication was significantly less (P=0.027) in the dexmedetomidine group.

Conclusion:

Intranasal dexmedetomidine appears to be a better choice for preanesthetic medication than oral midazolam in our study. Dexmedetomidine was associated with lower sedation levels, lower anxiety levels, and easier child-parent separation at the time of transferring patients to the operating room than children who received oral midazolam. Moreover, intranasal dexmedetomidine has better analgesic property than oral midazolam with discharge time from postanesthetic care unit similar to oral midazolam.