Formulation of Metoclopramide Hydrochloride-Loaded Lipid Carriers by QbD Approach for Combating Nausea: Safety and Bioavailability Evaluation in New Zealand Rabbit.

The focus of the research was to overcome the limitations of metoclopramide (MTC) when administered intranasally. The aim was to improve its bioavailability, increase patient compliance, and prolong its residence time in the nasal cavity. MTC-loaded liposomes were prepared by applying the film hydration method. A study was conducted to determine how formulation variables affected encapsulation efficiency (EE %), mean particle size (MPS), and zeta potential (ZP). The MTC-liposomes were further loaded into the in situ gel (gellan gum) for longer residence times following intranasal administration. pH, gelling time, and in vitro release tests were conducted on the formulations produced. In vivo performance of the MTC-loaded in situ gels was appraised based on disparate parameters such as plasma peak concentration, plasma peak time, and elimination coefficient compared to intravenous administration. When the optimal liposome formulation contained 1.98% of SPC, 0.081% of cholesterol, 97.84% of chloroform, and 0.1% of MTC, the EE of MTC was 83.21%, PS was 107.3 nm. After 5 h, more than 80% of the drug was released from MTC-loaded liposome incorporated into gellan gum in situ gel formulation (Lip-GG), which exhibited improved absorption and higher bioavailability compared to MTC loaded into gellan gum in situ gel (MTC-GG). Acceptable cell viability was also achieved. It was found out that MTC-loaded liposomal in situ gel formulations administered through the nasal route could be a better choice than other options due to its ease of administration, accurate dosing, and higher bioavailability in comparison with MTC-GG.

A green approach for metoclopramide quantification in pharmaceutical products: new HPLC and spectrophotometric methods.

Green spectrophotometric and HPLC methods have been developed for the quantification of metoclopramide. In the spectrophotometric method, it was determined by direct absorbance measurement at 273 nm wavelength using ultrapure water as solvent. The Extend C18 column was used for the HPLC method. The mobile phase system consisted of a combination of ethanol and formic acid solution (pH 2.0; 30:70 v/v). Isocratic elution was applied and the flow rate was set at 1.0 mL min-1. Metoclopramide was detected at 273 nm. The methods performed were economical, rapid, environmentally friendly, and simple, providing metoclopramide analysis within 5 min. The methods have been successfully applied in pharmaceutical products without matrix interference. The results of the application of the developed methods to pharmaceutical products were statistically compared and no significant difference was observed between the methods. In addition, the greenness assessment of the developed methods was performed using AGREE software. Our developed methods, based on the use of solvents such as ethanol and water, are proposed as a more environmentally and analyst-friendly option for the quantification of metoclopramide in pharmaceutical products than other methods currently in use.

The effectiveness of parenteral agents for pain reduction in patients with migraine presenting to emergency settings: A systematic review and network analysis.

OBJECTIVES: To assess the comparative effectiveness and safety of parenteral agents for pain reduction in patients with acute migraine. BACKGROUND: Parenteral agents have been shown to be effective in treating acute migraine pain; however, the comparative effectiveness of different approaches is unclear. METHODS: Nine electronic databases and gray literature sources were searched to identify randomized clinical trials assessing parenteral agents to treat acute migraine pain in emergency settings. Two independent reviewers completed study screening, data extraction, and Cochrane risk-of-bias assessment, with differences being resolved by adjudication. The protocol of the review was registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42018100096). RESULTS: A total of 97 unique studies were included, with most studies reporting a high or unclear risk of bias. Monotherapy, as well as combination therapy, successfully reduced pain scores prior to discharge. They also increased the proportion of patients reporting pain relief and being pain free. Across the pain outcomes assessed, combination therapy was one of the higher ranked approaches and provided robust improvements in pain outcomes, including lowering pain scores (mean difference -3.36, 95% confidence interval [CI] -4.64 to -2.08) and increasing the proportion of patients reporting pain relief (risk ratio [RR] 2.83, 95% CI 1.74-4.61). Neuroleptics and metoclopramide also ranked high in terms of the proportion of patients reporting pain relief (neuroleptics RR 2.76, 95% CI 2.12-3.60; metoclopramide RR 2.58, 95% CI 1.90-3.49) and being pain free before emergency department discharge (neuroleptics RR 4.8, 95% CI 3.61-6.49; metoclopramide RR 4.1, 95% CI 3.02-5.44). Most parenteral agents were associated with increased adverse events, particularly combination therapy and neuroleptics. CONCLUSIONS: Various parenteral agents were found to provide effective pain relief. Considering the consistent improvements across various outcomes, combination therapy, as well as monotherapy of either metoclopramide or neuroleptics are recommended as first-line options for managing acute migraine pain. There are risks of adverse events, especially akathisia, following treatment with these agents. We recommend that a shared decision-making model be considered to effectively identify the best treatment option based on the patient's needs.

Efficacy of acupoint injection of metoclopramide for post-chemotherapy vomiting: A systematic review and meta-analysis.

BACKGROUND: Vomiting is one of the most common adverse events of chemotherapy. The purpose of this study was to systematically review the clinical efficacy of acupoint injection of metoclopramide in the treatment of post-chemotherapy vomiting. METHODS: We searched 4 general English databases and 4 conventional Chinese databases, all with a time frame from database creation to December 2022. The retrieved clinical trials of acupoint injection of metoclopramide for post-chemotherapy vomiting were then subjected to meta-analysis and trial sequential analysis. RESULTS: A total of 12 studies were included, with a total sample size of 965 cases. Meta-analysis showed that acupoint injection of metoclopramide was effective in improving anti-vomiting effective rate [odds ratio = 5.67, 95% confidence interval = (3.80,8.47), P < .00001] compared with intramuscular/intravenous injection, and trial sequential analysis showed that this benefit was conclusive. Subgroup analysis demonstrated that acupoint injection significantly improved the anti-vomiting effective rate at doses of 10 mg qd, 20 mg qd, and 30 mg qd, as well as at durations of 1 day and 5 days. Subgroup analysis also indicated that injection at the Zusanli acupoint significantly increased the anti-vomiting effective rate, while injection at the Neiguan acupoint had an anti-vomiting effective rate comparable to that of the control group. Harbord regression showed no significant publication bias (P = .730). CONCLUSION: Acupoint injection of metoclopramide for post-chemotherapy vomiting is more effective than intramuscular and intravenous injections and is not limited by dose or duration of treatment, which may be the preferred way of administration.

Novel Lactation Induction Protocol for a Transgender Woman Wishing to Breastfeed: A Case Report.

Background: Lactation induction in transgender women is a clinical and research priority in the field of breastfeeding medicine. To date, there are four case reports detailing successful induced lactation in transgender patients who wished to breastfeed. The Academy of Breast Feeding Medicine does not formally recommend a specific medication regimen for transgender patients due to lack of high-quality research. Case Presentation: A 50-year-old transgender woman with a hypercoagulable disorder who was able to lactate and breastfeed with novel hormone regimen management at a gender care clinic. Her baseline hormone treatment was an estradiol 0.3 mg transdermal patch every 72 hours and micronized progesterone 200 mg daily. Results: Within four weeks of initiating a modified hormone regimen (estradiol 0.4 mg patch every 72 hours, progesterone 300 mg daily, metoclopramide 10 mg three times daily), the patient was lactating spontaneously. On multiple occasions, she breastfed and expressed up to 30 mL of milk through pumping. Conclusion: This report offers a new effective hormone regimen for transgender patients who wish to lactate and cannot access domperidone-the galactagogue used in previous case reports. It also provides a review of previously published case reports on this subject. Future research in this field should prioritize cohort studies of transgender patients who desire lactation to further assess patient attitudes, experiences, and outcomes.

Intravenous metoclopramide for increasing endoscopic mucosal visualization in patients with acute upper gastrointestinal bleeding: a multicenter, randomized, double-blind, controlled trial.

Acute upper gastrointestinal hemorrhage (UGIH) is the most common emergency condition that requires rapid endoscopic treatment. This study aimed to evaluate the effects of pre-endoscopic intravenous metoclopramide on endoscopic mucosal visualization (EMV) in patients with acute UGIH. This was a multicenter, randomized, double-blind controlled trial of participants diagnosed with acute UGIH. All participants underwent esophagogastroduodenoscopy within 24 h. Participants were assigned to either the metoclopramide or placebo group. Modified Avgerinos scores were evaluated during endoscopy. In total, 284 out of 300 patients completed the per-protocol procedure. The mean age was 62.8 ± 14.3 years, and 67.6% were men. Metoclopramide group achieved a higher total EMV and gastric body EMV score than the other group (7.34 ± 1.1 vs 6.94 ± 1.6; P = 0.017 and 1.80 ± 0.4 vs 1.64 ± 0.6; P = 0.006, respectively). Success in identifying lesions was not different between the groups (96.5% in metoclopramide and 93.6% in placebo group; P = 0.26). In the metoclopramide group, those with active variceal bleeding compared with the control group demonstrated substantial improvements in gastric EMV (1.83 ± 0.4 vs 1.28 ± 0.8, P = 0.004), antral EMV (1.96 ± 0.2 vs 1.56 ± 0.6, P = 0.003), and total EMV score (7.48 ± 1.1 vs 6.2 ± 2.3, P = 0.02). Pre-endoscopic intravenous metoclopramide improved the quality of EMV in variceal etiologies of UGIH, which was especially prominent in those who had signs of active bleeding based on nasogastric tube assessment.Trial Registration: Trial was registered in Clinical Trials: TCTR 20210708004 (08/07/2021).

The Management of Nausea and Vomiting in Pregnancy and Hyperemesis Gravidarum (Green-top Guideline No. 69).

An objective and validated index of nausea and vomiting such as the Pregnancy-Unique Quantification of Emesis (PUQE) and HyperEmesis Level Prediction (HELP) tools can be used to classify the severity of NVP and HG. [Grade C] Ketonuria is not an indicator of dehydration and should not be used to assess severity. [Grade A] There are safety and efficacy data for first line antiemetics such as anti (H1) histamines, phenothiazines and doxylamine/pyridoxine (Xonvea®) and they should be prescribed initially when required for NVP and HG (Appendix III). [Grade A] There is evidence that ondansetron is safe and effective. Its use as a second line antiemetic should not be discouraged if first line antiemetics are ineffective. Women can be reassured regarding a very small increase in the absolute risk of orofacial clefting with ondansetron use in the first trimester, which should be balanced with the risks of poorly managed HG. [Grade B] Metoclopramide is safe and effective and can be used alone or in combination with other antiemetics. [Grade B] Because of the risk of extrapyramidal effects metoclopramide should be used as second-line therapy. Intravenous doses should be administered by slow bolus injection over at least 3 minutes to help minimise these. [Grade C] Women should be asked about previous adverse reactions to antiemetic therapies. If adverse reactions occur, there should be prompt cessation of the medications. [GPP] Normal saline (0.9% NaCl) with additional potassium chloride in each bag, with administration guided by daily monitoring of electrolytes, is the most appropriate intravenous hydration. [Grade C] Combinations of different drugs should be used in women who do not respond to a single antiemetic. Suggested antiemetics for UK use are given in Appendix III. [GPP] Thiamine supplementation (either oral 100 mg tds or intravenous as part of vitamin B complex (Pabrinex®)) should be given to all women admitted with vomiting, or severely reduced dietary intake, especially before administration of dextrose or parenteral nutrition. [Grade D] All therapeutic measures should have been tried before considering termination of pregnancy. [Grade C].

Performance and Sensitivity of [99mTc]Tc-sestamibi Compared with Positron Emission Tomography Radiotracers to Measure P-glycoprotein Function in the Kidneys and Liver.

P-glycoprotein (P-gp, encoded in humans by the ABCB1 gene and in rodents by the Abcb1a/b genes) is a membrane transporter that can restrict the intestinal absorption and tissue distribution of many drugs and may also contribute to renal and hepatobiliary drug excretion. The aim of this study was to compare the performance and sensitivity of currently available radiolabeled P-gp substrates for positron emission tomography (PET) with the single-photon emission computed tomography (SPECT) radiotracer [99mTc]Tc-sestamibi for measuring the P-gp function in the kidneys and liver. Wild-type, heterozygous (Abcb1a/b(+/-)), and homozygous (Abcb1a/b(-/-)) Abcb1a/b knockout mice were used as models of different P-gp abundance in excretory organs. Animals underwent either dynamic PET scans after intravenous injection of [11C]N-desmethyl-loperamide, (R)-[11C]verapamil, or [11C]metoclopramide or consecutive static SPECT scans after intravenous injection of [99mTc]Tc-sestamibi. P-gp in the kidneys and liver of the mouse models was analyzed with immunofluorescence labeling and Western blotting. In the kidneys, Abcb1a/b() mice had intermediate P-gp abundance compared with wild-type and Abcb1a/b(-/-) mice. Among the four tested radiotracers, renal clearance of radioactivity (CLurine,kidney) was significantly reduced (-83%) in Abcb1a/b(-/-) mice only for [99mTc]Tc-sestamibi. Biliary clearance of radioactivity (CLbile,liver) was significantly reduced in Abcb1a/b(-/-) mice for [11C]N-desmethyl-loperamide (-47%), [11C]metoclopramide (-25%), and [99mTc]Tc-sestamibi (-79%). However, in Abcb1a/b(+/-) mice, CLbile,liver was significantly reduced (-47%) only for [99mTc]Tc-sestamibi. Among the tested radiotracers, [99mTc]Tc-sestamibi performed best in measuring the P-gp function in the kidneys and liver. Owing to its widespread clinical availability, [99mTc]Tc-sestamibi represents a promising probe substrate to assess systemic P-gp-mediated drug-drug interactions and to measure renal and hepatic P-gp function under different (patho-)physiological conditions.

Rare case report of moxifloxacin-induced persistent hiccups.

Moxifloxacin is a broad-spectrum antimicrobial agent that is commonly used in clinical practice. Here we report an unusual case of a patient with persistent hiccups caused by moxifloxacin. A man aged in his 40s was treated with moxifloxacin for tuberculous pleurisy. Hiccups occurred 2 hours after intravenous injection of moxifloxacin and lasted into evening. On the second day after injection, hiccups occurred again and made it difficult for him to fall asleep. The clinician ruled out gastrointestinal disease, nervous system disease, electrolyte disturbance and other factors. On assessing causality of the adverse drug reaction, the Naranjo scale for moxifloxacin was six, indicating a probable relationship of hiccups with moxifloxacin. Hiccups stopped 2 min after intramuscular injection of metoclopramide. To our knowledge, this is the first case report about moxifloxacin-induced persistent hiccups. Clinicians should be aware of the rare adverse reaction.

Palliative Management of Inoperable Malignant Bowel Obstruction: Prospective, Open Label, Phase 2 Study at an NCI Comprehensive Cancer Center.

CONTEXT: Malignant bowel obstruction (MBO) is a common complication of intra-abdominal cancer, frequently seen in advanced gastrointestinal and gynecologic cancer. Management of MBO can be challenging, particularly if the patient is not a surgical candidate. No consensus exists on how best to manage these patients medically. Retrospective studies suggest that the combination of dexamethasone, octreotide and metoclopramide may lead to relief of obstruction and improvement in symptoms associated with the obstruction. OBJECTIVES: This study seeks to prospectively evaluate the combination of drug "triple therapy" dexamethasone 4 mg BID, metoclopramide 10 mg Q6 and octreotide 300 mcg TID to assess tolerability, safety, and effect on symptoms and deobstruction. METHODS: Adults admitted at Roswell Park Comprehensive Cancer Center with malignant bowel obstruction were eligible. Eligible patients who constented to the study were started on the triple therapy with close monitoring of symptoms and for adverse effects. RESULTS: A total of 15 patients enrolled in the study. Two patients experienced bradycardia as adverse effect and there was no incidence of bowel perforation. All patients who completed the study had complete resolution of their nausea, and improvement in other symptoms including pain, constipation, tolerance of oral intake and resumption of bowel movements. Only two of the 15 patients were alive to complete the six-month post study follow up. CONCLUSION: "Triple therapy" with dexamethasone, metoclopramide, and octreotide for management of nonsurgical MBO in this small sample size appears safe and well tolerated however a diagnosis of inoperable MBO remains associated with poor prognosis and death within months.

D2 dopamine receptor-mediated mechanisms of dopaminergic system modulation in in vivo and in vitro experimental models of migraine.

The dopaminergic system is implicated in the pathophysiology of migraine. However, the underlying mechanisms remain unclear. We explored the effects and mechanisms of dopaminergic system modulation in the in vivo and in vitro rat models of migraine. Dopaminergic agonist apomorphine, D2 receptor antagonists metoclopramide and haloperidol and 5-HT3 receptor antagonist ondansetron alone and together were tested in nitroglycerin-induced migraine model, in vivo. Likewise, the combinations of drugs were also tested on basal calcitonin gene-related peptide (CGRP) release in vitro hemiskull preparations. Mechanical allodynia was tested by von Frey filaments. CGRP concentrations in trigeminovascular structures and in vitro superfusates and c-Fos levels in the brainstem were determined by enzyme-linked immunosorbent assay. Meningeal mast cells were evaluated with toluidine blue staining. Apomorphine further enhanced nitroglycerin-induced mechanical allodynia, brainstem c-fos expression, trigeminal ganglion and brainstem CGRP concentrations and meningeal mast cell degranulation, in vivo. Haloperidol completely antagonised all apomorphine-induced effects and also alleviated changes induced by nitroglycerin without apomorphine. Metoclopramide and ondansetron partially attenuated apomorphine- or nitroglycerin-induced effects. A combination of haloperidol and ondansetron decreased basal CGRP release, in vitro, whereas the other administrations were ineffective. Apomorphine-mediated dopaminergic activation exacerbated nitroglycerin-stimulated nociceptive reactions by further enhancing c-fos expression, CGRP release and mast cell degranulation in strategical structures associated with migraine pain. Metoclopramide partially attenuated the effects of apomorphine, most likely because it is also a 5-HT3 receptor antagonist. Haloperidol with pure D2 receptor antagonism feature appears to be more effective than metoclopramide in reducing migraine-related parameters in dopaminergic activation- and/or NTG-induced migraine-like conditions.

[11C]metoclopramide is a sensitive radiotracer to measure moderate decreases in P-glycoprotein function at the blood-brain barrier.

The efflux transporter P-glycoprotein (P-gp) at the blood-brain barrier limits the cerebral uptake of various xenobiotics. To assess the sensitivity of [11C]metoclopramide to measure decreased cerebral P-gp function, we performed [11C]metoclopramide PET scans without (baseline) and with partial P-gp inhibition by tariquidar in wild-type, heterozygous Abcb1a/b(+/-) and homozygous Abcb1a/b(-/-) mice as models with controlled levels of cerebral P-gp expression. Brains were collected to quantify P-gp expression with immunohistochemistry. Brain uptake of [11C]metoclopramide was expressed as the area under the brain time-activity curve (AUCbrain) and compared with data previously obtained with (R)-[11C]verapamil and [11C]N-desmethyl-loperamide. Abcb1a/b(+/-) mice had intermediate P-gp expression compared to wild-type and Abcb1a/b(-/-) mice. In baseline scans, all three radiotracers were able to discriminate Abcb1a/b(-/-) from wild-type mice (2.5- to 4.6-fold increased AUCbrain, p ≤ 0.0001). However, only [11C]metoclopramide could discriminate Abcb1a/b(+/-) from wild-type mice (1.46-fold increased AUCbrain, p ≤ 0.001). After partial P-gp inhibition, differences in [11C]metoclopramide AUCbrain between Abcb1a/b(+/-) and wild-type mice (1.39-fold, p ≤ 0.001) remained comparable to baseline. There was a negative correlation between baseline [11C]metoclopramide AUCbrain and ex-vivo-measured P-gp immunofluorescence (r = -0.9875, p ≤ 0.0001). Our data suggest that [11C]metoclopramide is a sensitive radiotracer to measure moderate, but (patho-)physiologically relevant decreases in cerebral P-gp function without the need to co-administer a P-gp inhibitor.

Is enhanced recovery after surgery essential?

BACKGROUND: The enhanced recovery after surgery (ERAS) method is designed for the patient to recover quickly, have less pain and have a more comfortable period after the surgery; that includes preoperative, intra and postoperative processes. ERAS has been started to be applied in cesarean section surgeries as the patients need to recover quickly. In the literature, there is no study about the results of ERAS in cesarean section about pain scores and complications. OBJECTIVES: It is aimed to compare the results of cesarean section patients using the ERAS method completely in patients who have had cesarean section without meeting some of the postoperative conditions of the ERAS criteria. STUDY DESIGN: It is a prospective study designed as postoperative metoclopramide, enema and routine opioids in group 1, enema and metoclopramide in group 2, metoclopramide only in group 3 and nothing in group 4. Postoperative pain scoring was done by using visual analog scale (VAS). Analysis of variance tests and t tests were used for results. RESULTS: There was no difference between groups according to age, parity, and birth weight. As a result, although there was no difference between the groups in terms of discharge time and complications, the VAS score used in pain scoring was found to be significantly lower in group 3 compared to the other groups (p: 0.000). Only metoclopramide group (group 3) had lowest VAS score. CONCLUSION: It has been revealed that the ERAS procedure does not need to be so detailed in the postoperative period, and the addition of metoclopramide may be sufficient. Since pain can be a subjective factor, other randomized studies are needed in terms of other criteria.

Metoclopramide-induced acute dystonic reaction: A pediatric case report.

INTRODUCTION: This case report presents a unique acute dystonic reaction (ADR) induced by metoclopramide in a 6-year-old male patient with pertussis-associated vomiting. The rarity of such a reaction in pediatric patients underscores the significance of this case in contributing to the scientific literature. This report highlights the need for heightened awareness of the potential adverse effects of medications commonly used in pediatrics and emphasizes the importance of tailored interventions for this population. MAIN SYMPTOMS AND IMPORTANT CLINICAL FINDINGS: Following the administration of metoclopramide for vomiting associated with pertussis cough, the patient exhibited distressing symptoms, including torticollis, facial grimacing, and tongue protrusion. These involuntary movements were promptly recognized, leading to the suspicion of an ADR. The clinical findings underscore the importance of vigilant monitoring for extrapyramidal symptoms following medication administration, especially in children. THE MAIN DIAGNOSES, THERAPEUTIC INTERVENTIONS, AND OUTCOMES: The primary diagnosis of ADR induced by metoclopramide was confirmed, prompting the cessation of the medication and the initiation of anticholinergic therapy with benztropine. This intervention rapidly resolved the patient's symptoms, highlighting the importance of tailored and swift therapeutic strategies. The outcome demonstrated the efficacy of timely intervention in managing ADR in pediatric patients. CONCLUSION: The main takeaway lesson from this case lies in the critical need for healthcare practitioners to remain vigilant for potential adverse reactions in pediatric patients, even when prescribing commonly used medications. The successful management of this case underscores the importance of prompt recognition, appropriate interventions, and continuous monitoring. Ultimately, this case contributes to the scientific literature by highlighting the unique manifestation of ADR in a pediatric patient, reinforcing the significance of individualized patient care and medication safety.

Prokinetics for the treatment of functional dyspepsia: an updated systematic review and network meta-analysis.

BACKGROUND: Since the previous network meta-analysis assessing the efficacy of prokinetics for functional dyspepsia (FD), there have been a number of new studies and cinitapride is a new prokinetic agent for FD. This updated meta-analysis aimed to explore the efficacy and safety of prokinetics for FD. METHODS: An updated study search in Pubmed, EMBASE, Cochrane Library and Web of Science was conducted in literatures published from July 2015 to March 2023. Randomized controlled trials investigating the use of prokinetics in adult FD patients were included. The primary outcome was the total efficacy rate and the secondary outcome was adverse events. A Bayesian network meta-analysis was performed using R software. RESULTS: A total of 28 studies were included. Network meta-analysis showed that metoclopramide had a higher total efficacy rate than mosapride (OR: 3.53, 95%CI: 1.70-7.47), domperidone (OR: 2.29, 95%CI: 1.16-4.63), itopride(OR: 2.77, 95%CI: 1.41-5.59), acotiamide(OR: 2.63, OR: 1.33-5.36), and placebo(OR: 5.68, 95%CI: 2.98-11.10), however similar to cinitapride (OR: 1.62, 95%CI: 0.75-3.53). Cinitapride had a higher total efficacy rate than mosapride (OR: 2.18, 95%CI: 1.16-4.14) and placebo (OR: 3.52, 95%CI: 2.01-6.24). Cinitapride had lower risk of total adverse events than domperidone. There was no difference in the risk of drug-related adverse events between the prokinetics. CONCLUSIONS: Metoclopramide and cinitapride may have a better efficacy than other prokinetics in the treatment of FD, and cinitapride may have a lower risk of total adverse events. Further studies using uniform definitions or validated tools to measure the total efficacy rate are needed.

Parametric Imaging of P-Glycoprotein Function at the Blood-Brain Barrier Using kE,brain-maps Generated from [11C]Metoclopramide PET Data in Rats, Nonhuman Primates and Humans.

PURPOSE: PET imaging using [11C]metoclopramide revealed the importance of P-glycoprotein (P-gp, ABCB1) in mediating the brain-to-blood efflux of substrates across the blood-brain barrier (BBB). In this work, the elimination rate constant from the brain (kE,brain), calculated from dynamic PET images without the need for arterial blood sampling, was evaluated as an outcome parameter for the interpretation of [11C]metoclopramide PET data. PROCEDURES: kE,brain parameter was obtained by linear regression of log-transformed brain time-activity curves (TACs). kE,brain values (h-1) obtained under baseline conditions were compared with values obtained after complete P-gp inhibition using tariquidar in rats (n = 4) and baboons (n = 4) or after partial inhibition using cyclosporine A in humans (n = 10). In baboons, the sensitivity of kE,brain to measure complete P-gp inhibition was compared with outcome parameters derived from kinetic modeling using a 1-tissue compartment model (1-TCM). Finally, kE,brain-maps were generated in each species using PMOD software. RESULTS: The linear part of the log-transformed brain TACs occurred from 10 to 30 min after radiotracer injection in rats, from 15 to 60 min in baboons, and from 20 to 60 min in humans. P-gp inhibition significantly decreased kE,brain values by 39 ± 12% in rats (p < 0.01), by 32 ± 6% in baboons (p < 0.001), and by 37 ± 22% in humans (p < 0.001). In baboons, P-gp inhibition consistently decreased the brain-to-plasma efflux rate constant k2 (36 ± 9%, p < 0.01) leading to an increase in the total brain volume of distribution (VT, 101 ± 12%, p < 0.001). In all studied species, brain kE,brain-maps displayed decreased P-gp-mediated efflux across the BBB. CONCLUSIONS: kE,brain of [11C]metoclopramide provides a simple outcome parameter to describe P-gp function in the living brain when arterial input function data are unavailable, although less sensitive than VT. kE,brain-maps represent easy to compute parametric images reflecting the effect of P-gp on [11C]metoclopramide elimination from the brain.

Pharmacological interventions for antipsychotic-related sialorrhea: a systematic review and network meta-analysis of randomized trials.

Antipsychotic-induced sialorrhea carries a significant burden, but evidence-based treatment guidance is incomplete, warranting network meta-analysis (NMA) of pharmacological interventions for antipsychotic-related sialorrhea. PubMed Central/PsycInfo/Cochrane Central database/Clinicaltrials.gov/WHO-ICTRP and the Chinese Electronic Journal Database (Qikan.cqvip.com) were searched for published/unpublished RCTs of antipsychotic-induced sialorrhea (any definition) in adults, up to 06/12/2023. We assessed global/local inconsistencies, publication bias, risk of bias (RoB2), and confidence in the evidence, conducting subgroup/sensitivity analyses. Co-primary efficacy outcomes were changes in saliva production (standardized mean difference/SMD) and study-defined response (risk ratios/RRs). The acceptability outcome was all-cause discontinuation (RR). Primary nodes were molecules; the mechanism of action (MoA) was secondary. Thirty-four RCTs entered a systematic review, 33 NMA (n = 1958). All interventions were for clozapine-induced sialorrhea in subjects with mental disorders. Regarding individual agents and response, metoclopramide (RR = 3.11, 95% C.I. = 1.39-6.98), cyproheptadine, (RR = 2.76, 95% C.I. = 2.00-3.82), sulpiride (RR = 2.49, 95% C.I. = 1.65-3.77), propantheline (RR = 2.39, 95% C.I. = 1.97-2.90), diphenhydramine (RR = 2.32, 95% C.I. = 1.88-2.86), benzhexol (RR = 2.32, 95% C.I. = 1.59-3.38), doxepin (RR = 2.30, 95% C.I. = 1.85-2.88), amisulpride (RR = 2.23, 95% C.I. = 1.30-3.81), chlorpheniramine (RR = 2.20, 95% C.I. = 1.67-2.89), amitriptyline (RR = 2.09, 95% C.I. = 1.34-3.26), atropine, (RR = 2.03, 95% C.I. = 1.22-3.38), and astemizole, (RR = 1.70, 95% C.I. = 1.28-2.26) outperformed placebo, but not glycopyrrolate or ipratropium. Across secondary nodes (k = 28, n = 1821), antimuscarinics (RR = 2.26, 95% C.I. = 1.91-2.68), benzamides (RR = 2.23, 95% C.I. = 1.75-3.10), TCAs (RR = 2.23, 95% C.I. = 1.83-2.72), and antihistamines (RR = 2.18, 95% C.I. = 1.83-2.59) outperformed placebo. In head-to-head comparisons, astemizole and ipratropium were outperformed by several interventions. All secondary nodes, except benzamides, outperformed the placebo on the continuous efficacy outcome. For nocturnal sialorrhea, neither benzamides nor atropine outperformed the placebo. Active interventions did not differ significantly from placebo regarding constipation or sleepiness/drowsiness. Low-confidence findings prompt caution in the interpretation of the results. Considering primary nodes' co-primary efficacy outcomes and head-to-head comparisons, efficacy for sialorrhea is most consistent for the following agents, decreasing from metoclopramide through cyproheptadine, sulpiride, propantheline, diphenhydramine, benzhexol, doxepin, amisulpride, chlorpheniramine, to amitriptyline, and atropine (the latter not for nocturnal sialorrhea). Shared decision-making with the patient should guide treatment decisions regarding clozapine-related sialorrhea.