Comparison of the Effects of Oral Midazolam and Intranasal Dexmedetomidine on Preoperative Sedation and Anesthesia Induction in Children Undergoing Surgeries

Background and Purpose: Premedication with either oral midazolam or intranasal dexmedetomidine prior to surgery remains less than ideal. The aim of this study was to investigate whether the combination of those two drug regimens would have any beneficial effects on the preoperative sedation and the children’s compliance during anesthesia inhalation induction.Experimental Approach: One hundred thirty-eight children aged 2–6 years were randomly allocated into three groups: Group M with oral midazolam 0.5 mg kg−1, Group D with intranasal dexmedetomidine 2 μg kg−1, and Group M + D with intranasal dexmedetomidine 1 μg kg−1 plus oral midazolam 0.5 mg kg−1. The primary outcome was the children’s compliance during inhalation induction with sevoflurane. The secondary outcomes included the preoperative sedative effects, behavior scores, parental separation anxiety scores, and the postoperative incidence of emergence agitation and recovery time.Results: Subjects in Group M + D showed higher satisfaction scores of compliance (p = 0.0049) and mask acceptance (MAS) (p = 0.0049) during anesthesia inhalation induction. Subjects in Group M + D had a significantly shorter time than those in Groups M and D to achieve the desired sedation level (p < 0.001) and remained at a higher sedation score in the holding area and up to the anesthesia induction after drug administration (p < 0.001).Conclusion and Implications: We conclude that pediatric patients premedicated with intranasal dexmedetomidine 1 μg kg−1 plus oral midazolam 0.5 mg kg−1 had significantly improved anesthesia induction compliance, and quicker onset to achieve and maintain a satisfactory level of sedation than those premedicated separately with two drugs. Therefore, the combined premed regimen is a greater choice when we are expecting a higher quality of sedation and a smoother anesthesia induction in children undergoing the surgeries.

Exploring the side effect profile of 16-Ethynyl Salvinorin A

<p>Introduction: Drug addiction is a chronic and relapsing disorder that has widespread socioeconomic and health consequences. Globally, there are over 29.5 million people who are drug dependent, and New Zealand has one of the highest rates of drug use rates in the developed world. Currently, there are no Food and Drug Administration (FDA) approved pharmacotherapies that target psychostimulant addiction. Kappa opioid receptor (KOPr) agonists are being studied as a potential pharmacotherapy as it utilizes the brain’s own mechanism for controlling reward, however, KOPr agonists have unwanted side effects such as dysphoria and sedation. This thesis explores the KOPr agonists Salvinorin A (Sal A), a naturally-occurring, highly potent and short-acting non-nitrogenous KOPr agonist and a structural analogue, 16-Ethynyl Salvinorin A (16-Ethy). KOPr agonists, such as Sal A have known preclinical anti-addictive and anti-reward effects, therefore, this thesis focuses on evaluating Sal A and 16-Ethy in preclinical tests of reward and side effects. Methods: Male Sprague-Dawley rats were used in preclinical tests to evaluate common KOPr-mediated side-effects including anxiety (elevated plus maze), depression (forced swim test) sedation (locomotor activity) and aversion (conditioned place aversion). The anti-cocaine effects were also examined using self-administration, dose-response and drug-behavioural sensitisation tests. 16-Ethy was tested at 2 mg/kg in all experiments. Results: Acute pre-treatment of 16-Ethy induced sedative effects in non-habituated locomotor activity but when rats were habituated prior to administration, no sedation was observed. In contrast, Sal A (2 mg/kg) had sedative effects in habituated, but not in non-habituated locomotor activity (p = 0.0037). Compared to vehicle-treated rats, 16-Ethy and Sal A did not display pro-depressive effects in the forced swim test, show anxiogenic or aversive properties or modulate behavioural sensitisation to cocaine. Cocaine self-administration and dose-response tests were not successfully completed. Conclusion: At 2 mg/kg, 16-Ethy was found to display sedative effects in non-habituated locomotor activity but not in a habituated paradigm. Compared to vehicle-treated rats, 16-Ethy did not display pro-depressive effects in the forced swim test, or display anxiogenic or aversive properties and did not show significant cocaine sensitisation. Cocaine self-administration and dose-response tests were not successfully completed and will need to be repeated to ascertain the effects of 16-Ethy on them. However, 16-Ethy has shown glimpses of promise as a potential pharmacotherapy against addiction.</p>

Exploring the side effect profile of 16-Ethynyl Salvinorin A

<p>Introduction: Drug addiction is a chronic and relapsing disorder that has widespread socioeconomic and health consequences. Globally, there are over 29.5 million people who are drug dependent, and New Zealand has one of the highest rates of drug use rates in the developed world. Currently, there are no Food and Drug Administration (FDA) approved pharmacotherapies that target psychostimulant addiction. Kappa opioid receptor (KOPr) agonists are being studied as a potential pharmacotherapy as it utilizes the brain’s own mechanism for controlling reward, however, KOPr agonists have unwanted side effects such as dysphoria and sedation. This thesis explores the KOPr agonists Salvinorin A (Sal A), a naturally-occurring, highly potent and short-acting non-nitrogenous KOPr agonist and a structural analogue, 16-Ethynyl Salvinorin A (16-Ethy). KOPr agonists, such as Sal A have known preclinical anti-addictive and anti-reward effects, therefore, this thesis focuses on evaluating Sal A and 16-Ethy in preclinical tests of reward and side effects. Methods: Male Sprague-Dawley rats were used in preclinical tests to evaluate common KOPr-mediated side-effects including anxiety (elevated plus maze), depression (forced swim test) sedation (locomotor activity) and aversion (conditioned place aversion). The anti-cocaine effects were also examined using self-administration, dose-response and drug-behavioural sensitisation tests. 16-Ethy was tested at 2 mg/kg in all experiments. Results: Acute pre-treatment of 16-Ethy induced sedative effects in non-habituated locomotor activity but when rats were habituated prior to administration, no sedation was observed. In contrast, Sal A (2 mg/kg) had sedative effects in habituated, but not in non-habituated locomotor activity (p = 0.0037). Compared to vehicle-treated rats, 16-Ethy and Sal A did not display pro-depressive effects in the forced swim test, show anxiogenic or aversive properties or modulate behavioural sensitisation to cocaine. Cocaine self-administration and dose-response tests were not successfully completed. Conclusion: At 2 mg/kg, 16-Ethy was found to display sedative effects in non-habituated locomotor activity but not in a habituated paradigm. Compared to vehicle-treated rats, 16-Ethy did not display pro-depressive effects in the forced swim test, or display anxiogenic or aversive properties and did not show significant cocaine sensitisation. Cocaine self-administration and dose-response tests were not successfully completed and will need to be repeated to ascertain the effects of 16-Ethy on them. However, 16-Ethy has shown glimpses of promise as a potential pharmacotherapy against addiction.</p>

Kappa Opioid Receptor Agonists: New Targets In The Treatment Of Pain

<p>Background and Purpose: Pain, although necessary for survival, can become pathological affecting an estimated 1 in 5 adults globally. It is also the most common reason people seek medical attention. Mu opioid receptor (MOPr) agonists, such as morphine, are the gold standard treatment for pain. Although these drugs have excellent analgesic properties, adverse effects such as addiction, tolerance and respiratory depression make their use problematic. An estimated 10,000 New Zealanders are addicted to prescription opiates, highlighting the need for better drugs to treat pain. Kappa opioid receptor (KOPr) agonists have analgesic properties and, unlike MOPr agonists, are also anti-addictive. Unfortunately, adverse effects such as sedation and dysphoria, have limited their therapeutic potential. The discovery of KOPr agonists that have analgesic properties without inducing adverse effects can allow for better, more efficient treatments of pain. We are the first to report the analgesic potential of novel Salvinorin A (Sal A) analogues: Tetrahydropyran Salvinorin A (THP Sal A) and Mesyl Salvinorin B (Mesyl Sal B). Experimental Approach and Compounds Tested: This study uses animal behavioural models to characterise the analgesic, anti-oedematous, sedative and hypothermic effects of a structurally new class of KOPr agonists including Sal A, THP Sal A and Mesyl Sal B. The known peripherally restricted KOPr agonist, ICI 204,448, was used to evaluate the peripherally mediated analgesic mechanisms of KOPr agonists. The tail-flick and intradermal formalin test were used to assess acute central and peripheral pain processes respectively. Sedative effects were monitored via rotarod performance test; thermoregulatory effects were also recorded. Key Results: ICI 204,448 attenuated inflammatory pain at a dose of 1 mg/kg (P<0.05, 30 min) and 2 mg/kg (P<0.001, 30-35 min). Although it showed no centrally mediated analgesic effects, it was found to be sedative at a dose of 2 mg/kg (P<0.01, 15-60 min). Sal A (2 mg/kg) attenuated inflammatory pain (P<0.01, 25-35 min) at the same dose it was sedative (P<0.01, 2-15 min). Although it treated acute thermal pain at a non-sedative dose (1 mg/kg, P<0.001, 10-15 min), it has a short duration of action (˜15 min). THP Sal A attenuated both thermal and inflammatory pain. Unfortunately, it was also sedative at both 1 mg/kg (P<0.01, 15-45 min) and 2 mg/kg (P<0.001, 15-90 min). Mesyl Sal B significantly attenuated both central (1mg/kg, P<0.01, 30-60 min) and peripheral (2 mg/kg, P<0.01, 30 min) pain processes. Although Mesyl Sal B was found to have a weak analgesic effect in all pain assays, it was not sedative. Conclusions and Implications: KOPr agonists attenuate acute nociceptive and inflammatory pain. Structural modification of Sal A at the C-2 position alters its analgesic effects in vivo. Substitution with a tetrahydropyran group greatly improves central analgesic effects; however, sedative effects were also observed. Although substitution with a mesylate group produced no sedative effects, it had reduced effects on central and peripheral pain processes. The lack of sedation by Mesyl Sal B makes it a good target for future research in pain. Its longer duration of action compared to Sal A suggests it has a better metabolic profile. The creation of more soluble KOPr compounds would allow for better dose-testing to evaluate therapeutic potential of KOPr analgesics.</p>

Kappa Opioid Receptor Agonists: New Targets In The Treatment Of Pain

<p>Background and Purpose: Pain, although necessary for survival, can become pathological affecting an estimated 1 in 5 adults globally. It is also the most common reason people seek medical attention. Mu opioid receptor (MOPr) agonists, such as morphine, are the gold standard treatment for pain. Although these drugs have excellent analgesic properties, adverse effects such as addiction, tolerance and respiratory depression make their use problematic. An estimated 10,000 New Zealanders are addicted to prescription opiates, highlighting the need for better drugs to treat pain. Kappa opioid receptor (KOPr) agonists have analgesic properties and, unlike MOPr agonists, are also anti-addictive. Unfortunately, adverse effects such as sedation and dysphoria, have limited their therapeutic potential. The discovery of KOPr agonists that have analgesic properties without inducing adverse effects can allow for better, more efficient treatments of pain. We are the first to report the analgesic potential of novel Salvinorin A (Sal A) analogues: Tetrahydropyran Salvinorin A (THP Sal A) and Mesyl Salvinorin B (Mesyl Sal B). Experimental Approach and Compounds Tested: This study uses animal behavioural models to characterise the analgesic, anti-oedematous, sedative and hypothermic effects of a structurally new class of KOPr agonists including Sal A, THP Sal A and Mesyl Sal B. The known peripherally restricted KOPr agonist, ICI 204,448, was used to evaluate the peripherally mediated analgesic mechanisms of KOPr agonists. The tail-flick and intradermal formalin test were used to assess acute central and peripheral pain processes respectively. Sedative effects were monitored via rotarod performance test; thermoregulatory effects were also recorded. Key Results: ICI 204,448 attenuated inflammatory pain at a dose of 1 mg/kg (P<0.05, 30 min) and 2 mg/kg (P<0.001, 30-35 min). Although it showed no centrally mediated analgesic effects, it was found to be sedative at a dose of 2 mg/kg (P<0.01, 15-60 min). Sal A (2 mg/kg) attenuated inflammatory pain (P<0.01, 25-35 min) at the same dose it was sedative (P<0.01, 2-15 min). Although it treated acute thermal pain at a non-sedative dose (1 mg/kg, P<0.001, 10-15 min), it has a short duration of action (˜15 min). THP Sal A attenuated both thermal and inflammatory pain. Unfortunately, it was also sedative at both 1 mg/kg (P<0.01, 15-45 min) and 2 mg/kg (P<0.001, 15-90 min). Mesyl Sal B significantly attenuated both central (1mg/kg, P<0.01, 30-60 min) and peripheral (2 mg/kg, P<0.01, 30 min) pain processes. Although Mesyl Sal B was found to have a weak analgesic effect in all pain assays, it was not sedative. Conclusions and Implications: KOPr agonists attenuate acute nociceptive and inflammatory pain. Structural modification of Sal A at the C-2 position alters its analgesic effects in vivo. Substitution with a tetrahydropyran group greatly improves central analgesic effects; however, sedative effects were also observed. Although substitution with a mesylate group produced no sedative effects, it had reduced effects on central and peripheral pain processes. The lack of sedation by Mesyl Sal B makes it a good target for future research in pain. Its longer duration of action compared to Sal A suggests it has a better metabolic profile. The creation of more soluble KOPr compounds would allow for better dose-testing to evaluate therapeutic potential of KOPr analgesics.</p>

Linarin, a Glycosylated Flavonoid, with Potential Therapeutic Attributes: A Comprehensive Review

Many flavonoids, as eminent phenolic compounds, have been commercialized and consumed as dietary supplements due to their incredible human health benefits. In the present study, a bioactive flavone glycoside linarin (LN) was designated to comprehensively overview its phytochemical and biological properties. LN has been characterized abundantly in the Cirsium, Micromeria, and Buddleja species belonging to Asteraceae, Lamiaceae, and Scrophulariaceae families, respectively. Biological assessments exhibited promising activities of LN, particularly, the remedial effects on central nervous system (CNS) disorders, whereas the remarkable sleep enhancing and sedative effects as well as AChE (acetylcholinesterase) inhibitory activity were highlighted. Of note, LN has indicated promising anti osteoblast proliferation and differentiation, thus a bone formation effect. Further biological and pharmacological assessments of LN and its optimized semi-synthetic derivatives, specifically its therapeutic characteristics on osteoarthritis and osteoporosis, might lead to uncovering potential drug candidates.

A PROSPECTIVE RANDOMIZED STUDY TO EVALUATE THE ANALGESIC AND SEDATIVE EFFECTS OF FENTANYL AND MIDAZOLAM TO NALBUPHINE AND MIDAZOLAM IN PATIENTS UNDERGOING AWAKE FIBEROPTIC

Background- Awake nasal or oral flexible fiberoptic intubation (AFOI) is technique of choice in known or anticipated difficult airway . The main aim was to have calm and cooperative patient who can follow verbal commands while maintaining adequate oxygenation . In our study, we compared the analgesic and sedative effects of fentanyl and midazolam with nalbuphine and midazolam in patients undergoing awake fiberoptic intubationmore tolerable and comfortable for the patient but also to ensure optimal intubating conditions. Material and Methods– A prospective, randomized comparison study among patients between the age of 18 and 60yrs of either sex, with anticipated difficult airway . We compared the analgesic and sedative effects of fentanyl and midazolam with nalbuphine and midazolam in patients undergoing awake fiberoptic intubation. The primary objectives of our study were to observe the level of sedation, intubation score and OAS score after completion of procedure. The secondary objectives included assessment of patient comfort, intubation time, hemodynamic changes and complications. Results – We found that comfort score and intubation time were significant lesser in Group which received fentanyl and midazolam than Group which received nalbuphine and midazolam . (p<0.05). The intubation attempt was similar in both groups (P>0.05). Conclusion– we concluded that both regimens used in this study provided comparable intubating conditions, better sedation and analgesia was observed in group fentanyl for airway procedure events. Our study concluded fentanyl to be the drug of choice for blunting of pressor response in such patients.