Perceptions of fentanyl among African Americans who misuse opioids: implications for risk reduction

BACKGROUND

Fentanyl is a powerful synthetic opioid that is 50 times more powerful than heroin and has become ubiquitous in the illicit drug supply in the USA. Studies show that among people who use drugs, fentanyl is sometimes viewed as a desirable substance due to its high potency and low cost, while others have an unfavorable perception because of its association with overdose. Unfortunately, studies on the perceptions of fentanyl are relatively rare and existing studies tend to rely on samples with little African American representation. The objective of this study, therefore, was to identify and describe perceptions of fentanyl among African Americans who misuse opioids, while capturing their motivations for seeking out or avoiding fentanyl.

METHODS

In-depth interviews (n = 30) were conducted with a sample of African American adults who misuse opioids in Southwest Florida between August 2021 and February 2022. Audiotapes of interviews were transcribed, coded, and thematically analyzed.

RESULTS

Analyses revealed the presence of three subtypes of fentanyl-related perceptions: (1) fentanyl as an avoided adulterant, (2) fentanyl as a tolerated adulterant, and (3) fentanyl as a drug of choice.

CONCLUSIONS

These findings show that African Americans' perceptions of fentanyl are not monolithic and suggest the distribution of fentanyl test strips and naloxone may be an effective risk reduction strategy. Given that most studies on fentanyl rely on quantitative data from drug seizures and death certificates, this study uniquely contributes to the literature by capturing the voices of African Americans who use drugs.

Continuous fentanyl administration and spontaneous withdrawal decreases home cage wheel running in rats with and without hindpaw inflammation

Fentanyl is a potent analgesic with a rapid onset and short half-life that make it a useful treatment for pain and a lethal drug of abuse. The present study used voluntary home cage wheel running to assess the effect of hindpaw inflammation, fentanyl administration, and spontaneous fentanyl withdrawal. Fentanyl (0.32 or 1.0 mg/kg/day) or placebo osmotic pumps were implanted subcutaneously and rats received an intraplantar injection of Complete Freund's Adjuvant (CFA) or saline. Rats with hindpaw inflammation caused by CFA administration were less active than rats injected with saline into the hindpaw. The antinociceptive effect of 0.32 mg/kg/day of fentanyl was evident as a recovery of wheel running in these rats. Administration of 1 mg/kg/day of fentanyl almost completely inhibited wheel running during the first day in rats with and without hindpaw inflammation. Wheel running increased each subsequent day until the pumps were surgically removed after day 3. Withdrawal from 0.32 or 1 mg/kg/day of fentanyl caused a decrease in wheel running that lasted 2 days in rats without hindpaw inflammation. In contrast, withdrawal was only evident following termination of 1 mg/kg/day of fentanyl in rats with hindpaw inflammation. This decrease in running seemed to persist beyond the 3 days of assessment. These data demonstrate that fentanyl can either depress or restore activity depending on the dose and pain condition. Moreover, termination of 3 days of continuous fentanyl administration resulted in a dose and time dependent decrease in wheel running consistent with opioid withdrawal.

The motives and methods of methamphetamine and 'heroin' co-use in West Virginia

BACKGROUND

Opioid and methamphetamine co-use is increasing across the USA with overdoses involving these drugs also rising. West Virginia (WV) has led the US in opioid overdose death rates since at least 2013 and rising co-use of methamphetamine with opioids has played a greater role in deaths over the last 5 years.

METHODS

This study used rapid ethnography to examine methods and motivations behind opioids and methamphetamine co-use from the viewpoint of their consumers. Participants (n = 30) were people who injected heroin/fentanyl also using methamphetamine who participated in semi-structured interviews.

RESULTS

We found multiple methods of co-using opioids and methamphetamine, whether alternately or simultaneously and in varying order. Most prioritized opioids, with motives for using methamphetamine forming three thematic categories: 'intrinsic use', encompassing both inherent pleasure of combined use greater than using both drugs separately or for self-medication of particular conditions; 'opioid assisting use' in which methamphetamine helped people manage their existing heroin/fentanyl use; and 'reluctant or indifferent use' for social participation, reflecting methamphetamine's low cost and easy availability.

CONCLUSIONS

Methamphetamine serves multiple functions among people using opioids in WV. Beliefs persist that methamphetamine can play a role in preventing and reversing opioid overdose, including some arguments for sequential use being protective of overdose. 'Reluctant' uptake attests to methamphetamine's social use and the influence of supply. The impact on overdose risk of the many varied co-use patterns needs further investigation.

Effect of the glucocorticoid receptor antagonist PT150 on acquisition and escalation of fentanyl self-administration following early-life stress

There is comorbidity between posttraumatic stress disorder (PTSD) and opioid use disorder (OUD), perhaps because PTSD-like stressful experiences early in life alter the hypothalamic-pituitary-adrenal stress axis to increase the risk for OUD. The present study determined if the glucocorticoid receptor antagonist PT150 reduces the escalation of fentanyl intake in rats exposed to a "two-hit" model of early-life stress (isolation rearing and acute stress). Male and female rats were raised during adolescence in either isolated or social housing and then were given either a single acute stress (restraint and cold-water swim) or control treatment in young adulthood. Rats were then treated daily with PT150 (50 mg/kg, oral) or placebo and were tested for acquisition of fentanyl self-administration in 1-hr sessions, followed by escalation across 6-hr sessions. Regardless of PT150 treatment or sex, acquisition of fentanyl self-administration in 1-hr sessions was greater in isolate-housed rats compared to social-housed rats; the acute stress manipulation did not have an effect on self-administration even though it transiently increased plasma corticosterone levels. During the 6-hr sessions, escalation of fentanyl was observed across all treatment groups; however, there was a significant PT150 Treatment × Sex interaction. While males self-administered more than females overall, PT150 decreased intake in males and increased intake in females, thus negating the sex difference. Although PT150 may serve as an effective treatment for reducing the risk of OUD following early-life stress in males, further work is needed to determine the mechanism underlying the differential effects of PT150 in males and females. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Nebulized fentanyl for respiratory symptoms in patients with COVID-19 (ventanyl trial)

Patients with coronavirus disease (COVID-19) commonly experience distressing and challenging respiratory symptoms. Interventions such as oxygen therapy, oral opiates, and traditional nebulizers like ipratropium bromide and salbutamol are variable in their efficacy, and therapy responses in patients are difficult to predict. The purpose of this study is to investigate the efficacy of nebulized fentanyl citrate on dyspnea, cough, and throat pain in patients with COVID-19 and evaluate the safety with any potential adverse events.In COVID-19, about 59% of patients will exhibit cough, 35% generalized body ache and sore throat, and 31% dyspnea. Some methods such as nebulized lidocaine, magnesium sulfate, and systemic opioids have been used to manage the respiratory symptoms. It has been previously shown that fentanyl nebulizer has beneficial effect in improving shortness of breath in patients with chronic obstructive pulmonary disease. The proposed theory behind that was that fentanyl decreased the rate of spontaneous respiratory rate, diminished the brain stem chemoreceptor response to hypoxia and hypercarbia, in addition to exhibiting a modulating effect on the brain stem. Therefore, we hypothesize that nebulized fentanyl has superior effect in improving shortness of breath and relieving cough compared to normal saline, in addition to its advantageous throat pain relief, while exhibiting fewer side effects in patients with COVID 19 infection. Therefore, this phase-III, randomized, comparative, parallel assignment, single-blinded clinical trial aims at assessing the efficacy and safety of nebulized fentanyl to suppress cough, improve breathlessness, and relieve throat pain in patients with COVID-19.

Predicting Maternal-Fetal Disposition of Fentanyl Following Intravenous and Epidural Administration Using Physiologically Based Pharmacokinetic Modeling

Fentanyl is an opioid analgesic used to treat obstetrical pain in parturient women through epidural or intravenous route, and unfortunately can also be abused by pregnant women. Fentanyl is known to cross the placental barrier, but how the route of administration and time after dosing affects maternal-fetal disposition kinetics at different stages of pregnancy is not well characterized. To address this knowledge gap, we developed a maternal-fetal physiologically based pharmacokinetic (mf-PBPK) model for fentanyl to evaluate the feasibility to predict the maternal and fetal plasma concentration-time profiles of fentanyl after various dosing regimens. As fentanyl is typically given via the epidural route to control labor pain, an epidural dosing site was developed using alfentanil as a reference drug and extrapolated to fentanyl. Fetal hepatic clearance of fentanyl was predicted from CYP3A7-mediated norfentanyl formation in fetal liver microsomes (intrinsic clearance = 0.20 ± 0.05 µl/min/mg protein). The developed mf-PBPK model successfully captured fentanyl maternal and umbilical cord concentrations after epidural dosing and was used to simulate the concentrations after intravenous dosing (in a drug abuse situation). The distribution kinetics of fentanyl were found to have a considerable impact on the time course of maternal:umbilical cord concentration ratio and on interpretation of observed data. The data show that mf-PBPK modeling can be used successfully to predict maternal disposition, transplacental distribution, and fetal exposure to fentanyl. SIGNIFICANCE STATEMENT: This study establishes the modeling framework for predicting the time course of maternal and fetal exposures of fentanyl opioids from mf-PBPK modeling. The model was validated based on fentanyl exposure data collected during labor and delivery after intravenous or epidural dosing. The results show that mf-PBPK modeling is a useful predictive tool for assessing fetal exposures to fentanyl opioid therapeutic regimens and potentially can be extended to other drugs of abuse.

Comparison of epidural, spinal, and saddle block for holmium laser enucleation of prostate (HoLEP): A prospective randomized, comparative study

BACKGROUND

Holmium laser enucleation of the prostate (HoLEP) has become an important treatment modality for benign prostate hypertrophy. The aim of the present study was to compare regional anesthesia methods for HoLEP operation and to determine the optimal technique.

METHODS

Sixty patients with American Society of Anesthesiologists scores of I-III were randomly allocated into 3 groups. Patients in group E received an epidural block with 75 mg of bupivacaine plus 50 μg of fentanyl. In group S, 15 mg of bupivacaine and 50 μg fentanyl were used for spinal anesthesia. In group SA, patients received saddle block with 15 mg of bupivacaine and 50 μg of fentanyl.

RESULTS

Time to T10 dermatome block and to maximal level block were longest in group E (P < .05), and maximal sensorial block level was higher in group E than group SA (P < .05). There was a significant difference in postoperative motor block, but no difference in systolic blood pressure and heart rate.

CONCLUSION

Among 3 techniques, saddle block might be preferable in HoLEP because an adequate sensorial level was achieved with lower motor block and stable hemodynamics.

Influence of ketamine versus fentanyl on pain relief for pediatric orthopedic emergencies: A meta-analysis of randomized controlled studies

INTRODUCTION

The comparison of ketamine with fentanyl for pain control of pediatric orthopedic emergencies remains controversial. We conduct a systematic review and meta-analysis to explore the influence of ketamine versus fentanyl on pain management among pediatric orthopedic emergencies.

METHODS

We have searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through September 2020 for randomized controlled trials assessing the effect of ketamine versus fentanyl on pain management for pediatric orthopedic emergencies.

RESULTS

Five randomized controlled trials are included in the meta-analysis. Overall, compared with fentanyl for pediatric orthopedic emergencies, ketamine led to similar change in pain scores at 15 to 20 minutes (standard mean difference = -0.05; 95% confidence interval [CI] = -0.38 to 0.28; P = .77) and 30 minutes (standard mean difference = 0.11; 95% CI = -0.20 to 0.42; P = .49), as well as rescue analgesia (RR = 0.90; 95% CI = 0.54 to 1.51; P = .69), but revealed the increase in nausea/vomiting (RR = 2.65; 95% CI = 1.13 to 6.18; P = .02) and dizziness (RR = 3.83; 95% CI = 1.38 to 10.60; P = .01).

CONCLUSIONS

Ketamine may be similar to fentanyl in terms of the analgesic efficacy for pediatric orthopedic emergencies.

Intravenous Infusion of Fentanyl Has No Effect on Blood Concentration of Tacrolimus in Patients Receiving Hematopoietic Stem-Cell Transplantation

BACKGROUND

Both tacrolimus (TAC) and fentanyl are frequently used in patients receiving allogeneic hematopoietic stem-cell transplantation. A recently published report demonstrated that fentanyl can reduce the total body clearance of TAC; however, most patients in this study were administered concomitantly with azole antifungal agents, which are known to be strong inhibitors of CYP3A. Hence, the exact effect of fentanyl on TAC pharmacokinetics was unclear. In the current study, the authors retrospectively investigated the pharmacokinetic interaction between TAC and fentanyl in patients who were not concomitantly administered drugs that affect TAC metabolism.

METHODS

Patients with continuous infusion of TAC and fentanyl after hematopoietic stem-cell transplantation at the Tokyo Medical and Dental University between January 2014 and December 2018 were enrolled. The total body clearance of TAC was compared before and after the initiation or discontinuation of fentanyl.

RESULTS

Thirty patients (24 men and 6 women; median age, 11 years) were screened for their eligibility. Twenty-eight patients were enrolled for evaluating the effects of the fentanyl initiation on TAC pharmacokinetics; 2 patients were excluded because of the absence of data related to the TAC blood concentrations or the concomitant use of azole antifungals. Twenty patients were enrolled for investigating the effects of fentanyl discontinuation on TAC pharmacokinetics, whereas 10 patients were excluded because of the absence of data related to the blood concentration of TAC or the additional administration of azole antifungals. Furthermore, the total body clearance of TAC was not significantly affected by the initiation or discontinuation of fentanyl, although there were large interindividual variations. In addition, the results remained the same even when the analysis was performed independently for adults and children.

CONCLUSIONS

Intravenous infusion of fentanyl does not affect the pharmacokinetics of TAC.

Functional Profile of Systemic and Intrathecal Cebranopadol in Nonhuman Primates

BACKGROUND

Cebranopadol, a mixed nociceptin/opioid receptor full agonist, can effectively relieve pain in rodents and humans. However, it is unclear to what degree different opioid receptor subtypes contribute to its antinociception and whether cebranopadol lacks acute opioid-associated side effects in primates. The authors hypothesized that coactivation of nociceptin receptors and μ receptors produces analgesia with reduced side effects in nonhuman primates.

METHODS

The antinociceptive, reinforcing, respiratory-depressant, and pruritic effects of cebranopadol in adult rhesus monkeys (n = 22) were compared with μ receptor agonists fentanyl and morphine using assays, including acute thermal nociception, IV drug self-administration, telemetric measurement of respiratory function, and itch-scratching responses.

RESULTS

Subcutaneous cebranopadol (ED50, 2.9 [95% CI, 1.8 to 4.6] μg/kg) potently produced antinociception compared to fentanyl (15.8 [14.6 to 17.1] μg/kg). Pretreatment with antagonists selective for nociceptin and μ receptors, but not δ and κ receptor antagonists, caused rightward shifts of the antinociceptive dose-response curve of cebranopadol with dose ratios of 2 and 9, respectively. Cebranopadol produced reinforcing effects comparable to fentanyl, but with decreased reinforcing strength, i.e., cebranopadol (mean ± SD, 7 ± 3 injections) versus fentanyl (12 ± 3 injections) determined by a progressive-ratio schedule of reinforcement. Unlike fentanyl (8 ± 2 breaths/min), systemic cebranopadol at higher doses did not decrease the respiratory rate (17 ± 2 breaths/min). Intrathecal cebranopadol (1 μg) exerted full antinociception with minimal scratching responses (231 ± 137 scratches) in contrast to intrathecal morphine (30 μg; 3,009 ± 1,474 scratches).

CONCLUSIONS

In nonhuman primates, the μ receptor mainly contributed to cebranopadol-induced antinociception. Similar to nociceptin/μ receptor partial agonists, cebranopadol displayed reduced side effects, such as a lack of respiratory depression and pruritus. Although cebranopadol showed reduced reinforcing strength, its detectable reinforcing effects and strength warrant caution, which is critical for the development and clinical use of cebranopadol.

EDITOR’S PERSPECTIVE

Escalation and reinstatement of fentanyl self-administration in male and female rats

RATIONALE

Escalation of drug intake and craving are two DSM-5 hallmark symptoms of opioid use disorder (OUD).

OBJECTIVES

This study determined if escalation of intake as modeled by long access (LgA) self-administration (SA) and craving measured by reinstatement are related.

METHODS

Adult male and female Sprague-Dawley rats were trained to self-administer fentanyl across 7 daily 1-h short access (ShA) sessions, followed by 21 SA sessions of either 1- or 6-h duration (ShA or LgA). Following 14 1-h extinction sessions, Experiment 1 assessed reinstatement induced by either fentanyl (10 or 30 µg/kg) or yohimbine (1 or 2 mg/kg), and Experiment 2 assessed reinstatement induced by a drug-associated cue light.

RESULTS

Females acquired fentanyl SA faster than males. When shifted to LgA sessions, LgA rats escalated fentanyl intake, but ShA rats did not; no reliable sex difference in the rate of escalation was observed. In extinction, compared to ShA rats, LgA rats initially responded less and showed less decay of responding across sessions. A priming injection of fentanyl induced reinstatement, with LgA rats reinstating more than ShA rats at the 30 µg/kg dose. Yohimbine (1 mg/kg) also induced reinstatement, but there was no effect of access group or sex. With cue-induced reinstatement, LgA females reinstated less than LgA males and ShA females.

CONCLUSION

Among the different reinstatement tests assessed, escalation of fentanyl SA increased only drug-primed reinstatement, suggesting a limited relationship between escalation of drug intake and craving (reinstatement) for OUD.

Comparison of efficacy between palonosetron-midazolam combination and palonosetron alone for prevention of postoperative nausea and vomiting in patients undergoing breast surgery and patient controlled analgesia: A prospective, randomized, double-blind study: A CONSORT-compliant study

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common complaint in patients following general anesthesia. Various antiemetics, including 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, are effective but still have limited efficacy. Therefore, combination therapy is preferable to using a single drug alone in high-risk patients. We performed a comparative study on the antiemetic effect of palonosetron, a 5-HT3 receptor antagonist, monotherapy vs palonosetron-midazolam combination therapy for the prevention of PONV.

METHODS

A total of 104 female patients scheduled for breast cancer surgery were enrolled. They were randomly divided into 2 groups, a palonosetron monotherapy group (group P) and palonosetron-midazolam combination therapy group (group PM). Both groups received 0.075 mg palonosetron intravenously after induction of anesthesia. Patient-controlled analgesia (PCA) was applied according to the allocated group. Intravenous (IV)-PCA in group P consisted of fentanyl 20 μg/kg plus normal saline (total volume: 100 ml); IV-PCA in group PM consisted of fentanyl 20 μg/kg plus midazolam 4 mg plus normal saline (total volume: 100 ml). Efficacy parameters were collected during 0 to 1, 1 to 6, 6 to 24, and 24 to 48 hours postoperative time intervals. These measures included complete response (defined as no PONV and no rescue anti-emetic use) rate, incidence of PONV, sedation score, rescue antiemetic use, rescue analgesic use, and numerical rating scale (NRS) for pain. The complete response rate during the 0 to 24 hours interval was analyzed as the primary outcome.

RESULTS

Although the complete response rate between 0 and 24 hours was higher in group PM (42.3% and 48.1% in group P and PM, respectively), there was no statistically significant difference (P = .55). The complete response rates in other time intervals were not different between the 2 groups as well. The sedation score and NRS score also showed no differences between the 2 groups.

CONCLUSIONS

The combination therapy of palonosetron with midazolam did not lead to a greater reduction in the incidence of PONV than monotherapy in patients undergoing breast surgery and receiving IV-PCA containing fentanyl.

A novel dual agonist of glucagon-like peptide-1 receptors and neuropeptide Y2 receptors attenuates fentanyl taking and seeking in male rats

There has been a dramatic increase in illicit fentanyl use in the United States over the last decade. In 2018, more than 31,000 overdose deaths involved fentanyl or fentanyl analogs, highlighting an urgent need to identify effective treatments for fentanyl use disorder. An emerging literature shows that glucagon-like peptide-1 receptor (GLP-1R) agonists attenuate the reinforcing efficacy of drugs of abuse. However, the effects of GLP-1R agonists on fentanyl-mediated behaviors are unknown. The first goal of this study was to determine if the GLP-1R agonist exendin-4 reduced fentanyl self-administration and the reinstatement of fentanyl-seeking behavior, an animal model of relapse, in rats. We found that systemic exendin-4 attenuated fentanyl taking and seeking at doses that also produced malaise-like effects in rats. To overcome these adverse effects and enhance the clinical potential of GLP-1R agonists, we recently developed a novel dual agonist of GLP-1Rs and neuropeptide Y2 receptors (Y2Rs), GEP44, that does not produce nausea-like behavior in drug-naïve rats or emesis in drug-naïve shrews. The second goal of this study was to determine if GEP44 reduced fentanyl self-administration and reinstatement with fewer adverse effects compared to exendin-4 alone. In contrast to exendin-4, GEP44 attenuated opioid taking and seeking at a dose that did not suppress food intake or produce adverse malaise-like effects in fentanyl-experienced rats. Taken together, these findings indicate a novel role for GLP-1Rs and Y2Rs in fentanyl reinforcement and highlight a potential new therapeutic approach to treating opioid use disorders.

Perioperative Opioid Consumption is Not Reduced in Cyanotic Patients Presenting for the Fontan Procedure

Adequate pain control is a critical component of the perioperative approach to children undergoing repair of congenital heart disease (CHD). The impact of specific anatomic and physiologic disturbances on the management of analgesia has been largely unexplored at the present time. Studies in other pediatric populations have found an association between chronic hypoxemia and an increased sensitivity to the effects of opioid medications. The purpose of this retrospective study was to examine perioperative opioid administration and opioid-associated adverse effects in children undergoing surgical repair of CHD, with a comparison between patients with and without chronic preoperative cyanosis. Patients between the ages of 2 and 5 years whose tracheas were extubated in the operating room were included and were classified in the cyanotic group if they presented for the Fontan completion. The primary outcomes of interest were intraoperative and postoperative opioid administration. Secondary outcomes included pain scores and opioid-related side effects. The study cohort included 156 patients. Seventy-one underwent the Fontan procedure, twelve of which were fenestrated. Fontan patients received fewer opioids intraoperatively (11.33 µg/kg fentanyl equivalents versus 12.56 µg/kg, p = 0.03). However, there were no differences with regards to opioid consumption postoperatively and no correlation between preoperative oxygen saturation and total opioid administration. There were no differences between groups with regards to the respiratory rate nadir, postoperative pain scores, or the incidence of opioid-related side effects. In contrast to other populations with chronic hypoxemia exposure, children with cyanotic CHD did not appear to have increased sensitivity to the effects of opioid medications.

Comparison of opioid local anesthetic combination regimens using the number of self-administrated boluses in patient-controlled epidural analgesia after cesarean section: A retrospective single-center study

ABSTRACT

The aim of this study was to assess the efficacy of combined opioids by comparing four regimens of patient-controlled epidural analgesia (PCEA) after cesarean section.Parturient patients who underwent elective or emergent cesarean section under combined spinal and epidural anesthesia from April 2013 to March 2016 were retrospectively analyzed. Based on PCEA, they were assigned to one of 4 groups: local anesthetic alone (LA), epidural single morphine administration during surgery followed by local anesthetic alone (M), local anesthetic combined with fentanyl 10 μg/h (F10), or local anesthetic combined with fentanyl 20 μg/h (F20). The primary outcome was the number of PCEA boluses used. Secondary outcomes included the use of rescue analgesia, postoperative nausea and vomiting, and postoperative pruritus.A total of 250 parturients were analyzed. Whereas the number of PCEA boluses in the LA group was significantly higher than in the other combined opioid groups on the day of surgery and postoperative day 1 (LA: 3 [1-6] and 7 [4-9] vs M: 2 [0-4] and 4 [0-7] vs F10: 1 [0-4] and 3 [0-6] vs F20: 1 [0-3] and 2 [0-8], P = .012 and 0.010, respectively), within the combined opioid groups, the number was not significantly different. Significantly fewer patients in the F20 group required rescue analgesia on postoperative day 1 and 2 (25 and 55%) than those in the M (66 and 81%) and F10 (62 and 66%) groups (P < .001 and P = .007, respectively). Postoperative nausea and vomiting and pruritus were significantly higher in the M group (P < .008 and P = .024, respectively).The results of the present study suggest that local anesthetic alone after a single administration of morphine, or local anesthetic combined with fentanyl 10 μg/h would generally be adequate for PCEA, whereas local anesthetic combined with fentanyl 20 μg/h would be suitable for conventional epidural analgesia.

Analgesic comparison of dezocine plus propofol versus fentanyl plus propofol for gastrointestinal endoscopy: A meta-analysis

INTRODUCTION

As the adjunctive anesthesia to propofol, both dezocine and fentanyl showed some potential for gastrointestinal endoscopy. This meta-analysis aimed to compare their efficacy and safety.

METHODS

PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of dezocine versus fentanyl for the anesthesia of patients undergoing gastrointestinal endoscopy were included.

RESULTS

Five RCTs involving 677 patients were included in the meta-analysis. Overall, compared with fentanyl plus propofol for gastrointestinal endoscopy, dezocine plus propofol resulted in the reduction in propofol dose(mean difference [MD] = -11.72; 95% confidence interval [CI] = -22.83 to -0.61; P = .04), awakening time (std. MD = -1.79; 95% CI = -3.31 to -0.27; P = .02) and hypopnea (risk ratio [RR] = 0.16; 95% CI = 0.06-0.41; P = .0002), but had no remarkable effect on induction time (MD = 1.20; 95% CI = -0.98 to 3.39; P = .28), postoperative pain score (MD = -0.38; 95% CI = -1.00 to 0.24; P = .24), nausea or vomiting (RR = 0.45; 95% CI = 0.10-1.98; P = .29).

CONCLUSION

Dezocine plus propofol may be better for the anesthesia of gastrointestinal endoscopy than fentanyl plus propofol.

Comparison of lidocaine, huffing maneuver and combination of both in prevention fentanyl induced cough before induction of anesthesia: a double-blind, prospective, randomized placebo-controlled study

BACKGROUND

Intravenous bolus injection of fentanyl has been frequently reported to be associated with cough reflex during patient anesthesia. However, the search for the most effective protocol continues. This study aimed to compare the effect of reducing cough reflex after injection of fentanyl in a fusion protocol by combining the injections of lidocaine and Huffing maneuver and comparing with a placebo control group, before anesthesia induction.

METHODS

This prospective randomized controlled trial study was performed on 400 patients who were divided into four groups of combined protocol (group 1), lidocaine group (group 2), Huffing maneuver group (group 3), and the control receiving normal saline (group 4). Then patients were injected with 2. 5 μg /kg fentanyl and monitored for 2 min regarding their cough reflex, as well as the severity.

RESULTS

In group one, 9 patients (9%), in group two, 45 patients (45%), 22 patients (22%) in group three, and in group four, 75 patients (75%), developed cough reflex following fentanyl injection. Also, 13 patients (13%) developed moderate and 4 (4%) developed severe coughs in the control group reported, while no reports of severe or moderate cough were among the intervention groups. There was a significant difference between the intervention group and the control group both in terms of the rate and severity of the fentanyl-induced cough.

CONCLUSION

By using a combination of lidocaine injection along and Huffing maneuver, better results can be obtained in reducing the frequency, and also the severity of cough followed by fentanyl injection.

TRIAL REGISTRATION

The trial was registered with IRCT.IR (09/03/2018-No. IRCT20141009019470N74 ).

Determination of equi-analgesic doses of inhaled methoxyflurane versus intravenous fentanyl using the cold pressor test in volunteers: a randomised, double-blinded, placebo-controlled crossover study

Background

Inhaled methoxyflurane for acute pain relief has demonstrated an analgesic effect superior to placebo. Data comparing methoxyflurane to an opioid are needed. The aim of this study was to determine the equi-analgesic doses of inhaled methoxyflurane vs i.v. fentanyl. Both drugs have an onset within minutes and an analgesic effect of 20–30 min.

Methods

Twelve subjects were included in a randomised, double-blinded, placebo-controlled crossover study with four treatments: placebo (NaCl 0.9%), fentanyl 25 μg i.v., fentanyl 50 μg i.v., or inhaled methoxyflurane 3 ml. The subjects reported pain intensity using the verbal numeric rating scale (VNRS) from 0 to 10 during the cold pressor test (CPT). The CPT was performed before (CPT 1), 5 min (CPT 2), and 20 min (CPT 3) after drug administration.

Results

Inhaled methoxyflurane and fentanyl 25 μg reduced VNRS scores significantly compared with placebo at CPT 2 (–1.14 [estimated difference in VNRS between treatment groups with 95% confidence interval {CI}: –1.50 to –0.78]; –1.15 [95% CI: –1.51 to –0.79]; both P<0.001) and CPT 3 (–0.60 [95% CI: –0.96 to –0.24]; –0.84 [95% CI: –1.20 to –0.47]; both P<0.001). There were no significant differences between the two drugs. Methoxyflurane had significantly higher VNRS scores than fentanyl 50 μg at CPT 2 (0.90 [95% CI: 0.54–1.26]; P<0.001) and CPT 3 (0.57 [95% CI: 0.21–0.94]; P<0.001).

Conclusions

Inhaled methoxyflurane 3 ml was equi-analgesic to fentanyl 25 μg i.v. at CPT 2. Both resulted in significantly less pain than placebo. Fentanyl 50 μg i.v. demonstrated analgesia superior to methoxyflurane.

Clinical trial registration

NCT03894800

Tolerance to Opioid-Induced Respiratory Depression in Chronic High-Dose Opioid Users: A Model-Based Comparison With Opioid-Naïve Individuals

Chronic opioid consumption is associated with addiction, physical dependence, and tolerance. Tolerance results in dose escalation to maintain the desired opioid effect. Intake of high-dose or potent opioids may cause life-threatening respiratory depression, an effect that may be reduced by tolerance. We performed a pharmacokinetic-pharmacodynamic analysis of the respiratory effects of fentanyl in chronic opioid users and opioid-naïve subjects to quantify tolerance to respiratory depression. Fourteen opioid-naïve individuals and eight chronic opioid users received escalating doses of intravenous fentanyl (opioid-naïve subjects: 75-350 µg/70 kg; chronic users: 250-700 µg/70 kg). Isohypercapnic ventilation was measured and the fentanyl plasma concentration-ventilation data were analyzed using nonlinear mixed-effects modeling. Apneic events occurred in opioid-naïve subjects after a cumulative fentanyl dose (per 70 kg) of 225 (n = 3) and 475 µg (n = 6), and in 7 chronic opioid users after a cumulative dose of 600 (n = 2), 1,100 (n = 2), and 1,800 µg (n = 3). The time course of fentanyl's respiratory depressant effect was characterized using a biophase equilibration model in combination with an inhibitory maximum effect (Emax ) model. Differences in tolerance between populations were successfully modeled. The effect-site concentration causing 50% ventilatory depression, was 0.42 ± 0.07 ng/mL in opioid-naïve subjects and 1.82 ± 0.39 ng/mL in chronic opioid users, indicative of a 4.3-fold sensitivity difference. Despite higher tolerance to fentanyl-induced respiratory depression, apnea still occurred in the opioid-tolerant population indicative of the potential danger of high-dose opioids in causing life-threatening respiratory depression in all individuals, opioid-naïve and opioid-tolerant.

Early adolescent subchronic low-dose nicotine exposure increases subsequent cocaine and fentanyl self-administration in Sprague-Dawley rats

An exponential rise in nicotine-containing electronic-cigarette use has been observed during the period of adolescence. Preclinical studies have shown that nicotine exposure during early adolescence, but not adulthood, increases subsequent drug intake and reward. Although growing clinical trends highlight that stimulant use disorders are associated with the opioid epidemic, very few studies have assessed the effects of adolescent nicotine exposure on opioid intake. The objective of our current study is to develop a new animal model to assess the causal relationship of adolescent nicotine exposure on subsequent opioid intake. In this effort, we first replicate previous studies using a well-established 4-day nicotine paradigm. Rats are pretreated with a low dose of nicotine (2 × , 30 μg/kg/0.1 mL, intravenous) or saline during early adolescence (postnatal days 28-31) or adulthood (postnatal days 86-89). Following nicotine pretreatment on postnatal day 32 or postnatal day 90, animals underwent operant intravenous self-administration for the psychostimulant, cocaine [500 μg/kg/infusion (inf)] or the opioid, fentanyl (2.5 μg/kg/inf). We successfully show that adolescent but not adult, nicotine exposure enhances cocaine self-administration in male rats. Furthermore, we illustrate early adolescent but not adult nicotine exposure enhances fentanyl self-administration, independent of sex. Overall, our findings highlight that adolescence is a unique period of development that is vulnerable to nicotine-induced enhancement for cocaine and fentanyl self-administration in rats.

The influence of cardiac output on propofol and fentanyl pharmacokinetics and pharmacodynamics in patients undergoing abdominal aortic surgery

Cardiac output (CO) is expected to affect elimination and distribution of highly extracted and perfusion rate-limited drugs. This work was undertaken to quantify the effect of CO measured by the pulse pressure method on pharmacokinetics and pharmacodynamics of propofol and fentanyl administrated during total intravenous anesthesia (TIVA). The data were obtained from 22 ASA III patients undergoing abdominal aortic surgery. Propofol was administered via target-controlled infusion system (Diprifusor) and fentanyl was administered at a dose of 2-3 µg/kg each time analgesia appeared to be inadequate. Hemodynamic measurements as well as bispectral index were monitored and recorded throughout the surgery. Data analysis was performed by using a non-linear mixed-effect population modeling (NONMEM 7.4 software). Three compartment models that incorporated blood flows as parameters were used to describe propofol and fentanyl pharmacokinetics. The delay of the anesthetic effect, with respect to plasma concentrations, was described using a biophase (effect) compartment. The bispectral index was linked to the propofol and fentanyl effect site concentrations through a synergistic Emax model. An empirical linear model was used to describe CO changes observed during the surgery. Cardiac output was identified as an important predictor of propofol and fentanyl pharmacokinetics. Consequently, it affected the depth of anesthesia and the recovery time after propofol-fentanyl TIVA infusion cessation. The model predicted (not observed) CO values correlated best with measured responses. Patients' age was identified as a covariate affecting the rate of CO changes during the anesthesia leading to age-related difference in individual patient's responses to both drugs.

Pain management in patients with chronic kidney disease and end-stage kidney disease

PURPOSE OF REVIEW

This review evaluates current recommendations for pain management in chronic kidney disease (CKD) and end-stage kidney disease (ESKD) with a specific focus on evidence for opioid analgesia, including the partial agonist, buprenorphine.

RECENT FINDINGS

Recent evidence supports the use of physical activity and other nonpharmacologic therapies, either alone or with pharmacological therapies, for pain management. Nonopioid analgesics, including acetaminophen, topical analgesics, gabapentinoids, serotonin-norepinephrine reuptake inhibitors, and TCA may be considered based on pain cause and type, with careful dose considerations in kidney disease. NSAIDs may be used in CKD and ESKD for short durations with careful monitoring. Opioid use should be minimized and reserved for patients who have failed other therapies. Opioids have been associated with increased adverse events in this population, and thus should be used cautiously after risk/benefit discussion with the patient. Opioids that are safer to use in kidney disease include oxycodone, hydromorphone, fentanyl, methadone, and buprenorphine. Buprenorphine appears to be a promising and safer option due to its partial agonism at the mu opioid receptor.

SUMMARY

Pain is poorly managed in patients with kidney disease. Nonpharmacological and nonopioid analgesics should be first-line approaches for pain management. Opioid use should be minimized with careful monitoring and dose adjustment.

Anticipatory prescribing in community end-of-life care in the UK and Ireland during the COVID-19 pandemic: online survey

BACKGROUND

Anticipatory prescribing (AP) of injectable medications in advance of clinical need is established practice in community end-of-life care. Changes to prescribing guidelines and practice have been reported during the COVID-19 pandemic.

AIMS AND OBJECTIVES

To investigate UK and Ireland clinicians' experiences concerning changes in AP during the COVID-19 pandemic and their recommendations for change.

METHODS

Online survey of participants at previous AP national workshops, members of the Association for Palliative Medicine of Great Britain and Ireland and other professional organisations, with snowball sampling.

RESULTS

Two hundred and sixty-one replies were received between 9 and 19 April 2020 from clinicians in community, hospice and hospital settings across all areas of the UK and Ireland. Changes to AP local guidance and practice were reported: route of administration (47%), drugs prescribed (38%), total quantities prescribed (35%), doses and ranges (29%). Concerns over shortages of nurses and doctors to administer subcutaneous injections led 37% to consider drug administration by family or social caregivers, often by buccal, sublingual and transdermal routes. Clinical contact and patient assessment were more often remote via telephone or video (63%). Recommendations for regulatory changes to permit drug repurposing and easier community access were made.

CONCLUSIONS

The challenges of the COVID-19 pandemic for UK community palliative care has stimulated rapid innovation in AP. The extent to which these are implemented and their clinical efficacy need further examination.