Safety and pharmacokinetic properties of a new formulation of parenteral artesunate in healthy Thai volunteers.

BACKGROUND: Parenteral artesunate is the first-line therapy for severe malaria. Artesunate, in its current formulation, must be prepared immediately before administration by first dissolving in sodium bicarbonate solution and then diluting in saline. A novel solvent for rapid and stable single step reconstitution of artesunate was recently developed showing improved solubility and stability. This study aimed to compare the safety and pharmacokinetic properties of the currently available and newly developed parenteral formulation of artesunate in healthy Thai volunteers. METHODS: This was an open-label, randomized, 4 periods, 4-treatments, 24-sequence, single-dose, cross-over study in 72 male and female healthy Thai volunteers. Frequent pharmacokinetic samples were collected in all volunteers at each dose occasion. Observed concentration-time profiles were analysed with a non-compartmental approach followed by a bioequivalence evaluation. RESULTS: Both intramuscular and intravenous administrations of the new parenteral formulation of artesunate were safe and well-tolerated, with no additional safety signals compared to the currently used formulation. The pharmacokinetic properties of artesunate and its active metabolite, dihydroartemisinin, were well-characterized, and showed rapid conversion of artesunate into dihydroartemisinin. Intramuscular administration of the newly formulated artesunate resulted in almost complete bioavailability of dihydroartemisinin. The pharmacokinetic properties were similar between the old and new formulation. CONCLUSIONS: The new and more easily prepared formulation of artesunate was safe and well-tolerated, with similar pharmacokinetic properties compared to the currently used formulation. Dihydroartemisinin, the active metabolite responsible for the majority of the anti-malarial effect, showed equivalent exposure after both intravenous and intramuscular administration of artesunate, suggesting that both routes of administration should generate comparable therapeutic effects. TRIAL REGISTRATION: The study was registered to clinicaltrials.gov (#TCTR20170907002).

Examining the Safety of Dorsogluteal and Ventrogluteal Sites for Intramuscular Injection in Older Adults.

BACKGROUND: Muscle, subcutaneous tissue and total tissue thicknesses are important factors in successful intramuscular injection. Muscle mass decreases and subcutaneous tissue increases with age. This may negatively affect the safety and effectiveness of intramuscular injection in older adults by increasing the risk of bone contact and subcutaneous drug administration. Intramuscular injection sites should be evaluated in this respect, but no previous study has evaluated the most appropriate sites for safe and effective intramuscular injection in older adults. OBJECTIVES: This study aimed to examine the safety of dorsogluteal and ventrogluteal injection sites in older adults. METHODS: This cross-sectional study included 171 older adults who presented to the radiology clinic of a hospital between November 2022 and February 2023. We collected the study data using a descriptive characteristics form and an ultrasonographic measurement form. To complete the descriptive characteristics form, we interviewed the participants and measured their waist circumference, hip circumference, weight and height. Muscle, subcutaneous tissue and total tissue thicknesses at the ventrogluteal and dorsogluteal sites were determined by ultrasonography. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guideline. RESULTS: At the ventrogluteal and dorsogluteal sites, respectively, total tissue thicknesses were 59.43 ± 11.21 and 48.78 ± 9.68 mm, subcutaneous tissue thicknesses were 20.07 ± 6.64 and 22.97 ± 7.40 mm and muscle thicknesses were 40.13 ± 5.59 and 25.61 ± 4.30 mm. Tissue thicknesses at both sites differed according to sex, weight, hip circumference and waist circumference (p < 0.05). Although both sites were acceptable according to the tissue thickness thresholds for intramuscular injection given in the literature (subcutaneous tissue < 25 mm, total tissue > 35 mm), the ventrogluteal site was more advantageous in terms of greater muscle thickness and lower subcutaneous tissue thickness. CONCLUSIONS: The results of this study indicated that both the ventrogluteal and dorsogluteal sites are safe for intramuscular injections in older adults in terms of tissue thickness. However, the ventrogluteal site may be safer for older adults because of the lower risk of bone contact and subcutaneous injection. Further studies are needed on this subject. IMPLICATIONS FOR PRACTICE: This study is important in terms of determining the safe and effective gluteal site for IM injection in older people aged 65 and over, preventing complications that may arise from site selection, and developing nursing policies that consider older people as a special group in the selection of IM injection sites.

[Vitamin B9 and B12 : clinical manifestations, screening and substitution]. / Vitamine B9 et B12 : manifestations cliniques, dépistage et substitution.

Deficiency in vitamins B9 and B12 are common in general practice, due to their high prevalence in the population, especially among elderly patients. This article will present the clinical manifestations of vitamin B9 and B12 deficiencies, which can sometimes be insidious. We will discuss screening strategies, which are based on the presence of compatible symptoms as well as risk factors for deficiency. The choice of administration route for substitution depends both on severity and etiology; but the oral route has demonstrated similar effectiveness compared to intramuscular administration.

Il est courant de rencontrer des déficits en vitamines B9 et B12 en consultation de médecine de premier recours, en raison de leurs prévalences élevées dans la population générale, surtout chez les patients âgés. Cet article présente les manifestations cliniques de carences en vitamines B9 et B12, qui peuvent parfois être insidieuses et discute des stratégies de dépistage, qui se basent sur la présence de symptômes compatibles ainsi que de facteurs de risque de carence. Concernant la substitution, le choix de la voie d'administration se fait selon la sévérité et l'étiologie ; mais la forme orale a démontré une efficacité similaire à l'administration intramusculaire.

Role of size, surface charge, and PEGylated lipids of lipid nanoparticles (LNPs) on intramuscular delivery of mRNA.

Lipid nanoparticles (LNPs) are currently the most commonly used non-viral gene delivery system. Their physiochemical attributes, encompassing size, charge and surface modifications, significantly affect their behaviors both in vivo and in vitro. Nevertheless, the effects of these properties on the transfection and distribution of LNPs after intramuscular injection remain elusive. In this study, LNPs with varying sizes, lipid-based charges and PEGylated lipids were formulated to study their transfection and in vivo distribution. Luciferase mRNA (mLuc) was entraped in LNPs as a model nucleic acid molecule. Results indicated that smaller-sized LNPs and those with neutral potential presented superior transfection efficiency after intramuscular injection. Surprisingly, the sizes and charges did not exert a notable influence on the in vivo distribution of the LNPs. Furthermore, PEGylated lipids with shorter acyl chains contributed to enhanced transfection efficiency due to their superior cellular uptake and lysosomal escape capabilities. Notably, the mechanisms underlying cellular uptake differed among LNPs containing various types of PEGylated lipids, which was primarily attributed to the length of their acyl chain. Together, these insights underscore the pivotal role of nanoparticle characteristics and PEGylated lipids in the intramuscular route. This study not only fills crucial knowledge gaps but also provides significant directions for the effective delivery of mRNA via LNPs.

DAXXIFYTM (DaxibotulinumtoxinA-Lanm) for Injection, for Intramuscular Use.

DAXXIFYTM (daxibotulinumtoxinA-lanm) for intramuscular injection was recently approved for temporary improvement in the appearance of the moderate to severe glabellar lines (GLs) associated with corrugator and/or procerus muscle activity in adult patients. DaxibotulinumtoxinA for Injection (DAXI) includes a purified 150-kDA botulinum toxin Type A (BoNTA) formulated with a novel peptide excipient that is positively charged and helps to bind the neurotoxin to negatively charged neuronal membrane for a longer duration. The effectiveness of DAXI was evaluated in two phase 3 trials, SAKURA 1 and SAKURA 2, using a randomized, double-blind, placebo-controlled design. The primary endpoint (treatment success) was a composite clinical outcome (investigator and subjects) of ≥2-point improvement in severity of GLs at week 4. In SAKURA 1, the treatment success was 74% (148/201) in subjects treated with DAXI and 0% in subjects treated with placebo. In SAKURA 2, the treatment success was 74% (152/205) in subjects treated with DAXI and 0% in subjects treated with placebo. An open-label study, SAKURA 3, included 2,691 participants, who underwent three consecutive treatment cycles. These individuals were recruited from either SAKURA 1 or SAKURA 2 trials, or were new to the study and received DAXI. Treatment success proportions were 73.2%, 77.7%, and 79.6% across the three consecutive treatment cycles. The recommended dose is 40 units for the Glabellar-complex divided in traditional five intramuscular injections at five injection sites (medial and lateral corrugator bilaterally and one injection in the procerus muscle).

Interim safety and immunogenicity analysis of the EuCorVac-19 COVID-19 vaccine in a Phase 3 randomized, observer-blind, immunobridging trial in the Philippines.

EuCorVac-19 (ECV-19) is a recombinant receptor binding domain (RBD) COVID-19 vaccine that displays the RBD (derived from the SARS-CoV-2 Wuhan strain) on immunogenic liposomes. This study compares the safety and immunogenicity of ECV-19 to the COVISHIELDTM (CS) adenoviral-vectored vaccine. Interim analysis is presented of a randomized, observer-blind, immunobridging Phase 3 trial in the Philippines in 2600 subjects, with treatment and biospecimen collection between October 2022 and January 2023. Healthy male and female adults who received investigational vaccines were 18 years and older, and randomly assigned to ECV-19 (n = 2004) or CS (n = 596) groups. Immunization followed a two-injection, intramuscular regimen with 4 weeks between prime and boost vaccination. Safety endpoints were assessed in all participants and immunogenicity analysis was carried out in a subset (n = 585 in ECV-19 and n = 290 in CS groups). The primary immunological endpoints were superiority of neutralizing antibody response, as well as noninferiority in seroresponse rate (defined as a 4-fold increase in RBD antibody titers from baseline). After prime vaccination, ECV-19 had a lower incidence of local solicited adverse events (AEs) (12.0% vs. 15.8%, p < 0.01), and solicited systemic AEs (13.1 vs. 17.4%, p < 0.01) relative to CS. After the second injection, both ECV-19 and CS had lower overall solicited AEs (7.8% vs. 7.6%). For immunological assessment, 98% of participants had prior COVID-19 exposure (based on the presence of anti-nucleocapsid antibodies) at the time of the initial immunization, without differing baseline antibody levels or microneutralization (MN) titers against the Wuhan strain in the two groups. After prime vaccination, ECV-19 induced higher anti-RBD IgG relative to CS (1,464 vs. 355 BAU/mL, p < 0.001) and higher neutralizing antibody response (1,303 vs. 494 MN titer, p < 0.001). After boost vaccination, ECV-19 and CS maintained those levels of anti-RBD IgG (1367 vs. 344 BAU/mL, p < 0.001) and neutralizing antibodies (1128 vs. 469 MN titer, p < 0.001). ECV-19 also elicited antibodies that better neutralized the Omicron variant, compared to CS (763 vs. 373 MN titer, p < 0.001). Women displayed higher responses to both vaccines than men. The ECV-19 group had a greater seroresponse rate compared to CS (83% vs. 30%, p < 0.001). In summary, both ECV-19 and CS had favorable safety profiles, with ECV-19 showing diminished local and systemic solicited AE after prime immunization. ECV-19 had significantly greater immunogenicity in terms of anti-RBD IgG, neutralizing antibodies, and seroresponse rate. These data establish a relatively favorable safety and immunogenicity profile for ECV-19. The trial is registered on ClinicalTrials.gov (NCT05572879).

New Insight in Using of Mesenchyme Stem Cell Conditioning Medium for the Impaired Muscle related Biomarkers: In vivo Study with Rat Model.

AIMS AND OBJECTIVES: This study aimed to investigate the effects of Umbilical Cord Mesencymal Stem Cell Conditioning Medium (UC MSC-CM) administration on body weight recovery and the level of four molecular biomarkers, namely Superoxide Dismutase (SOD), vascular Endothelial Growth Factor (VEGF), C-Reactive Protein (CRP), and myostatin. MATERIALS AND METHODS: Secretome was injected intramuscularly twice at 1.5 mL (day 7 and 14) into the right thigh of high-dose, short-term galactose-induced aging rats. The data of day 7 (before) and day 21 (after the administration) were evaluated. The body weights and the four biomarkers were measured before (day 7) and after intervention (day 21). RESULTS: This study showed that the UC MSC-CM intramuscular administrations did not influence body weight regeneration. However, it could increase SOD and VEGF levels and decrease CRP and myostatin levels. CONCLUSION: Treatment with UC MSC-CM is a promising and potential agent in treating sarcopenia.

Résumé Buts et objectifs:Cette étude visait à examiner les effets de l'administration d'un milieu de conditionnement de cellules souches mésencéphaliques de cordon ombilical (UC MSC-CM) sur la récupération du poids corporel et le niveau de quatre biomarqueurs moléculaires, à savoir la superoxyde dismutase (SOD), le facteur de croissance endothéliale vasculaire (VEGF), la protéine C-réactive (CRP) et la myostatine.Matériels et méthodes:Le sécrétome (UC MSC-CM) a été injecté par voie intramusculaire deux fois à 1,5 ml (jour 7 et 14) dans la cuisse droite de rats vieillissant à forte dose et à court terme induits par le galactose. Les données du jour 7 (avant) et du jour 21 (après l'administration) ont été évaluées. Le poids corporel et les quatre biomarqueurs ont été mesurés avant (jour 7) et après l'intervention (jour 21).Résultats:Cette étude a montré que les administrations intramusculaires de CSM-CM d'UC n'ont pas influencé la régénération du poids corporel. Cependant, elle a pu augmenter les niveaux de SOD et de VEGF et diminuer les niveaux de CRP et de myostatine.Conclusion:Le traitement par UC MSC-CM est un agent prometteur et potentiel dans le traitement de la sarcopénie.

Comparing the outcomes of in-vitro fertilization in patients receiving vaginal, subcutaneous, and intramuscular progesterone for luteal phase support: a three-armed randomized controlled trial.

BACKGROUND: The optimal approach to luteal-phase support in infertility treatment remains a subject of debate. This study was conducted to investigate the clinical outcomes, side effects, and patient satisfaction associated with vaginal, subcutaneous, and intramuscular progesterone administration in infertile women undergoing Frozen Embryo Transfer (FET). METHODS: This three-armed randomized clinical trial assigned infertile patients eligible for FET to three progesterone treatment groups: vaginal suppositories (400 mg twice daily; n = 100), subcutaneous injections (25 mg daily; n = 102), and intramuscular injections (50 mg daily; n = 108). The primary outcomes were chemical and clinical pregnancy rates per embryo transfer cycle, with chemical pregnancy defined as beta-human chorionic gonadotropin levels > 50 IU/mL two weeks post-transfer and clinical pregnancy confirmed by ultrasound four weeks later. Exploratory outcomes included progesterone-related adverse effects and participant satisfaction, assessed via a Likert-scale survey 12 weeks post-transfer. Statistical analyses included Chi-square tests for categorical data, one-way analysis of variances, and Kruskal-Wallis tests for continuous data. RESULTS: The intramuscular progesterone group had significantly higher chemical pregnancy rates compared to the vaginal and subcutaneous groups (41.7% vs. 26.0% and 27.5%, respectively; p = 0.026). Although the clinical pregnancy rate was also higher in the intramuscular group (32.4%) compared to the vaginal (23.0%) and subcutaneous groups (21.6%), this difference was not statistically significant (p = 0.148). Additionally, patient satisfaction was greater with vaginal and subcutaneous applications than with intramuscular injections (p < 0.001), likely due to a significantly higher incidence of side effects, such as pain and edema at the injection site, in the intramuscular group (p < 0.001). CONCLUSIONS: We found that intramuscular progesterone resulted in higher chemical pregnancy rates than vaginal or subcutaneous routes, but this did not translate into higher clinical pregnancy rates. Despite its effectiveness, intramuscular administration was associated with more adverse effects and lower patient satisfaction. Future research should explore optimizing progesterone regimens to balance efficacy and patient comfort. TRIAL REGISTRATION: The trial protocol was registered on December 6, 2020, in the Iranian Registry of Clinical Trials (IRCT), a primary registry in the World Health Organization (WHO) Registry Network, under the registration number IRCT20141217020351N12.

Effects of Short-Term Treatment of Rabbit Extraocular Muscle With Ciliary Neurotrophic Factor.

Purpose: Little is known about the effect of ciliary neurotrophic factor (CNTF) on extraocular muscles, but microarray studies suggested CNTF might play a role in the development and/or maintenance of strabismus. The effect of short-term treatment of adult rabbit extraocular muscle with injected CNTF was examined for its ability to alter muscle characteristics. Methods: Eight adult New Zealand white rabbits received an injection into one superior rectus muscle of 2 µg/100 µL CNTF on 3 consecutive days. One week after the first injection, the rabbits were euthanized, and the treated and contralateral superior rectus muscles were assessed for force generation capacity and contraction characteristics using an in vitro stimulation protocol and compared to naïve control superior rectus muscles. All muscles were analyzed to determine mean cross-sectional areas and expression of slow twitch myosin heavy chain isoform. Results: Short-term treatment of rabbit superior rectus muscles with CNTF resulted in a significant decrease in muscle force generation, but only at the higher stimulation frequencies. Significantly decreased myofiber cross-sectional areas of the treated muscles correlated with the decreased generated force. In addition, there were significant changes to contractile properties of the treated muscles, as well as a decrease in the number of myofibers expressing slow twitch myosin heavy chain. Conclusions: We show that short-term treatment of a single rabbit superior rectus muscle results in decreased myofiber size, decreased force, and altered contractile characteristics. Further studies are needed to determine if it can play a role in improving alignment in animal models of strabismus.

An Ultrasonographic Analysis of the Deep Inferior Tendon in the Masseter Muscle: Implications for Botulinum Toxin Injections.

(1) Background: With the increasing aesthetic pursuit of facial features, the clinical use of Botulinum Toxin Type A (BoNT-A) injections for masseter hypertrophy has been on the rise. However, due to variations in masseter muscle structure and differences in clinicians' injection techniques, blind injections may lack precision, potentially compromising treatment accuracy and increasing the risk of complications. (2) Objectives: The study aims to use ultrasonography to detail the deep inferior tendon (DIT) within the masseter muscle in a young Chinese cohort, refine its classification, analyze muscle belly thickness and variations across groups, and propose a customized ultrasound-guided BoNT-A injection protocol. (3) Methods: Ultrasound imaging was used to observe the bilateral masseter muscles at rest and during clenching. The features of the DIT were classified from these images, and the thickness of the masseter's distinct bellies associated with the DIT types was measured in both states. (4) Results: The study cohort included 103 participants (27 male, 76 female), with 30 muscles in the normal masseter group and 176 muscles in the hypertrophy group. The DIT was categorized as Type A, B (subtypes B1, B2), and C. The distribution of these types was consistent across normal, hypertrophic, and gender groups, all following the same trend (B > A > C). In hypertrophy, Type B1 showed uniform thickness across masseter bellies, B2 presented with a thinner intermediate belly, and Type C had mainly superficial muscle enlargement. Changes in muscle thickness during clenching were noted but not statistically significant among different bellies. (5) Conclusions: The study evidences individual variation in the DIT, highlighting the importance of precise DIT classification for effective BoNT-A injections. A tailored ultrasound-guided BoNT-A injection strategy based on this classification may enhance safety and efficacy of the therapy.

Effect of post-mating administration of ketoprofen on serum progesterone concentration and fertility in Akkaraman ewes.

A major cause of early embryonic losses is inadequate secretion of progesterone (P4) hormone due to luteal insufficiency in farm animals. Post-mating applications that directly or indirectly increasing serum P4 concentrations have a positive effect on fertility. The aim of this study was to investigate the effect of post-mating administration of ketoprofen on serum P4 concentration and fertility in Akkaraman ewes synchronized with a short-term protocol during the breeding season. Oestrus monitoring ewes after synchronization were hand-mated and randomly assigned to two equal groups (Ketoprofen vs. Control). Ewes in the ketoprofen group (KPG) (n = 40) were administered with ketoprofen (Rifen, Richter pharma, Austria) intramuscularly (im) at a dose of 3 mg/kg on days 9 and 10 after mating. In the control group (CG) ewes (n = 40) were administered with saline im on the same days. Blood samples were collected from ewes in both groups at four different time points of post-mating days (9, 12, 15 and 18 days). The results showed that there were no statistical differences between the KPG and CG groups on fertility parameters; pregnancy rates (85% vs. 72.5%), lambing rates (100% vs. 100%), single birth rates (55.9% vs. 55.2%), multiple birth rates (44.1% vs. 44.8%), litter sizes (1.56 vs. 1.55). In pregnant ewes, serum P4 concentrations on day 18 (4.35 ± 0.34 ng/mL) in the KPG group were higher than (3.27 ± 0.27 ng/mL) in CG group (P < 0.05). It was concluded that post-mating ketoprofen administration have no significant effect on fertility, but significantly increased the serum P4 concentration on day 18 in pregnant ewes.

Safety and Pharmacokinetics of Nirsevimab in Immunocompromised Children.

BACKGROUND AND OBJECTIVES: Immunocompromised children may have increased risk for severe respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI), potentially leading to prolonged hospitalization, intensive care, and death. The open-label phase II MUSIC trial evaluated the safety and pharmacokinetics of nirsevimab, an extended half-life monoclonal antibody against RSV, in immunocompromised children aged ≤24 months. METHODS: Participants received a single intramuscular injection of nirsevimab (first RSV season: 50 mg if <5 kg/100 mg if ≥5 kg; second season: 200 mg). Safety, antidrug antibodies, and pharmacokinetics were evaluated to day 361. RESULTS: Participants (n = 100) had ≥1 immunocompromising conditions: primary immunodeficiency (n = 33), previous transplantation (n = 16), HIV infection (n = 8) or treatment with high-dose systemic corticosteroids (n = 29), immunosuppressive chemotherapy (n = 20), or other immunosuppressive therapies (n = 15). Six children experienced eight treatment-related adverse events (none categorized as serious). Three deaths occurred, all were unrelated to treatment. Eleven children, developed antidrug antibodies, with minimal effects on pharmacokinetics and no apparent impact on safety. Nirsevimab serum concentrations at day 151 were similar to those effective in preventing medically attended RSV LRTI in healthy infants. Fourteen children had increased nirsevimab clearance. No protocol-defined medically attended RSV LRTIs occured through day 151. CONCLUSIONS: Among immunocompromised children aged ≤24 months, nirsevimab was well tolerated with no safety concerns and serum concentrations were supportive of efficacy. A subset of children with increased nirsevimab clearance, had conditions potentially associated with protein loss; however, the impact on efficacy is unknown.

Pharmacokinetic profiles of methylcobalamin in rats after multiple administration routes by a simple LC-MS/MS assay with a small volume of plasma.

Methylcobalamin (MBL) is a vitamin B12 coenzyme and is effective for treating peripheral neuropathies. Little is known about pharmacokinetics (PK) of MBL in animals, we have developed a simple assay for MBL by using only 0.01 mL of plasma for PK of MBL in rats. Under minimal light exposure (<5 lx), MBL was extracted by a simple protein precipitation using methanol and detected by liquid chromatography with tandem mass spectrometry. MBL in rat plasma at 20-10,000 ng/mL was quantified using only 0.01 mL of plasma. Relative error and relative standard deviation met the acceptance criteria in reproducibility assessments, indicating the robustness of the assay. PK of MBL was evaluated after intravenous, intramuscular, and subcutaneous administration. PK of MBL was dose proportional at 5-20 mg/kg in both intramuscular and subcutaneous administrations. Bioavailability after the two dosing routes was complete (ca. 100 %). The incurred sample reanalysis also supported that the assay is robust. The established assay was successfully applied to PK studies in rats to find that MBL showed high bioavailability after intramuscular and subcutaneous administrations.

Effectiveness of intramuscular naloxone 1,600 µg in addition to titrated intravenous naloxone 100 µg for opioid poisoning: a randomised controlled trial.

INTRODUCTION: Naloxone is an effective antidote, but its short half-life means repeated doses, and infusions are often required. We investigated the effectiveness of adding intramuscular naloxone to titrated intravenous naloxone in opioid overdose in preventing recurrence of respiratory depression. METHODS: This double-blinded randomised placebo-controlled trial was conducted in patients with suspected opioid poisoning and respiratory depression (respiratory rate <10 breaths/min or oxygen saturation <93%). Patients were randomised to receive either intramuscular naloxone 1,600 µg or saline placebo. All patients received titrated intravenous naloxone 100 µg and were managed on an opioid poisoning care pathway. The primary outcome was recurrence of respiratory depression within 4 h. Secondary outcomes were the proportion receiving naloxone infusions, number of naloxone boluses administered, reversal of respiratory depression at 10 min, and precipitation of opioid withdrawal (any symptom). RESULTS: Recurrence of respiratory depression within 4 h was less common in 28/69 (41%) patients receiving intramuscular naloxone versus 48/67 (72%) patients receiving placebo (difference 31%, 95% CI: 13-46%; P < 0.001). Fewer naloxone infusions (5/69; 7% versus 25/67; 37%, difference 30%, 95% CI: 15 to 55%; P < 0.001) and fewer naloxone doses were administered (median 2, IQR: 1 to 5, versus median 5, IQR: 2 to 8; P = 0.001) in the intramuscular group. Reversal of respiratory depression at 10 min was similar between groups (51/69; 74% intramuscular naloxone versus 47/67; 70% placebo; P = 0.703). Opioid withdrawal occurred in 35/69 (51%) given intramuscular naloxone compared to 28/67 (42%) in the placebo group (difference 9%; 95% CI: -8 to 27%; P = 0.308). DISCUSSION: The favourable pharmacokinetics of intramuscular naloxone, particularly its longer duration of activity, likely explains the improved effectiveness with lower recurrence of respiratory depression. CONCLUSION: The addition of intramuscular naloxone 1,600 µg to titrated intravenous naloxone prolonged effective reversal of respiratory depression, with fewer naloxone doses and infusions given, and no significant difference in patients developing withdrawal.

A single dose of recombinant adenoviral vector rabies vaccine expressing two copies of glycoprotein protects mice from lethal virus challenge.

INTRODUCTION: Rabies is a fatal infectious disease, that poses a major public health threat in developing countries. With an annual death toll of approximately 59,000, more than half of which are children, an urgent need exists for a safe, affordable, and effective preventive measure against rabies virus infection. METHODOLOGY: A recombinant rabies vaccine called Ad5-dRVG was constructed by introducing two copies of the rabies virus glycoprotein into a human adenoviral vector. Virus-neutralizing assays and virus challenge experiments were employed to evaluate the Ad5-dRVG vaccine. RESULTS: Our findings demonstrate that a single dose of Ad5-dRVG, administered either intramuscularly or orally, elicited significantly stronger immune responses than Ad5-RVG. Moreover, both vaccines provided complete protection in mice. Notably, the vaccine exhibited remarkable efficacy even at low doses, suggesting potential cost reduction in production. CONCLUSIONS: The development of the Ad5-dRVG recombinant rabies vaccine represents a significant advancement in rabies prevention. Its enhanced immunogenicity, demonstrated efficacy and potential cost savings make it a promising candidate for widespread use.

Long-term antibiotic prophylaxis for prevention of rheumatic fever recurrence and progression to rheumatic heart disease.

BACKGROUND: Rheumatic fever is a non-suppurative, inflammatory sequela of group A Streptococcus pharyngitis that can occur at two to four weeks after infection. Following an episode of rheumatic fever, there is a risk of developing rheumatic heart disease (RHD) later in life that carries significant risk of morbidity and mortality. RHD remains the largest global cause of cardiovascular disease in the young (age < 25 years). The historical literature provides inconclusive evidence that antibiotic prophylaxis is beneficial in reducing the risk of recurrence of rheumatic fever and development of RHD. Antibiotics are thought to work by reducing the carriage of group A Streptococcus and thus reducing the risk of infection. This review was commissioned by the World Health Organization (WHO) for an upcoming guideline. OBJECTIVES: 1. To assess the effects of long-term antibiotics versus no antibiotics (control) for secondary prevention of rheumatic fever recurrence and associated sequelae in people with previous rheumatic fever or RHD. 2. To assess the effects of long-term intramuscular penicillin versus long-term oral antibiotics for secondary prevention of rheumatic fever recurrence and associated sequelae in people with previous rheumatic fever or RHD. SEARCH METHODS: We systematically searched CENTRAL, MEDLINE, Embase, Conference Proceedings Citation Index-Science, clinical trial registers, ISRCTN.com and reference lists without restrictions on language or date up to 10 March 2024. SELECTION CRITERIA: We sought randomised controlled trials or quasi-randomised trials, described in any language, including participants with previous rheumatic fever and/or RHD of any age, based in community or hospital settings. Studies were included if they compared firstly antibiotic prophylaxis with no antibiotic prophylaxis, and, secondly, intramuscular penicillin prophylaxis versus oral antibiotic prophylaxis. DATA COLLECTION AND ANALYSIS: We used standardised methodological, Cochrane-endorsed procedures and performed meta-analyses with risk ratios (RR) and Peto odds ratios (Peto OR). Our primary outcomes were recurrence of rheumatic fever, progression or severity of RHD and cardiac complications. Our secondary outcomes were obstetric complications (maternal and foetal events), mortality, treatment adherence, adverse events and acceptability to participants. We performed comprehensive assessments of risk of bias and certainty of evidence, applying the GRADE methodology. MAIN RESULTS: We included 11 studies (seven RCTs and four quasi-randomised trials) including 3951 participants. The majority of the included studies were conducted in the USA, UK and Canada during the 1950s to 1960s. Most participants with previous rheumatic fever had been diagnosed using the modified Jones criteria (mJC) (four studies), were an average of 12.3 years of age and 50.6% male. We assessed the majority of the included studies to be at high risk of bias, predominantly relating to blinding and attrition bias. Comparison one: antibiotics versus no antibiotics Pooled meta-analysis of six RCTs provides moderate-certainty evidence that antibiotics overall (oral or intramuscular) probably reduce the risk of recurrence of rheumatic fever substantially (0.7% versus 1.7%, respectively) (risk ratio (RR) 0.39, 95% confidence interval (CI) 0.22 to 0.69; 1721 participants). People with early or mild RHD likely have the greatest capacity to benefit from intramuscular antibiotic prophylaxis (8.1%) compared to no antibiotics (0.7%) (RR 0.09, 95% CI 0.03 to 0.29; 1 study, 818 participants; moderate-certainty evidence). Antibiotics may not affect mortality in people with late-stage RHD (RR 1.23, 95% CI 0.78 to 1.94; 1 study, 994 participants; low-certainty evidence). Antibiotics may not affect the risk of anaphylaxis (Peto odds ratio (OR) 7.39, 95% CI 0.15 to 372; 1 study, 818 participants; low-certainty evidence) or sciatic nerve injury (Peto OR 7.39, 95% CI 0.15 to 372; 1 study, 818 participants; low-certainty evidence) compared with no antibiotics, but probably have an increased risk of hypersensitivity reactions (RR 137, 8.51 to 2210; 2 studies, 894 participants; moderate-certainty evidence) and local reactions (RR 29, 1.74 to 485; 1 study, 818 participants; moderate-certainty evidence). Comparison two: intramuscular antibiotics versus oral antibiotics Pooled analysis of two RCTs showed that prophylactic intramuscular benzathine benzylpenicillin likely reduces recurrence of rheumatic fever substantially when compared to oral antibiotics (0.1% versus 1%, respectively) (RR 0.07, 95% CI 0.02 to 0.26; 395 participants; moderate-certainty evidence). Furthermore, it is unclear whether intramuscular benzyl penicillin is superior to oral antibiotics in reducing the risk of mortality in the context of RHD (Peto OR 0.22, 95% CI 0.01 to 4.12; 1 study, 431 participants; very low-certainty evidence). There were no data available on progression of latent RHD or adverse events including anaphylaxis, sciatic nerve injury, delayed hypersensitivity/allergic reactions and local reactions to injection. AUTHORS' CONCLUSIONS: This review provides evidence that antibiotic prophylaxis likely reduces the risk of recurrence of rheumatic fever compared to no antibiotics, and that intramuscular benzathine benzylpenicillin is probably superior to oral antibiotics (approximately 10 times better). Moreover, intramuscular benzathine benzylpenicillin likely reduces the risk of progression of latent RHD. Evidence is scarce, but antibiotics compared with no antibiotics may not affect the risk of anaphylaxis or sciatic nerve injury, but probably carry an increased risk of hypersensitivity reactions and local reactions. Antibiotics may not affect all-cause mortality in late-stage RHD compared to no antibiotics. There is no evidence available to comment on the effect of intramuscular penicillin over oral antibiotics for progression of latent RHD and adverse events, and little evidence for all-cause mortality. It is important to interpret these findings in the context of major limitations, including the following: the vast majority of the included studies were conducted more than 50 years ago, many before contemporary echocardiographic studies; methodology was often at high risk of bias; outdated treatments were used; only one study was in latent RHD; and there are concerns regarding generalisability to low socioeconomic regions. This underlines the need for ongoing research to understand who benefits most from prophylaxis.

Parenteral iron nutrition: Iron dextran-poloxamer thermosensitive hydrogel for prolonged intramuscular iron supplementation.

The objective of this study was to evaluate the potential of novel poloxamer thermosensitive hydrogels (PTHs) formulations for prolonged release of iron dextran particles (IDP) for intramuscular (IM) injection. The thermosensitive behaviour helps to avoid hepcidin overexpression and toxicity by releasing IDPs without iron accumulation in injection or deposit sites. We hypothesized that novel PTH formulation would prolong iron liberation compared to the commercial iron dextran formulation (FEDEX). PTHs loaded with IDPs were developed with increasing iron content (0.1, 0.2 and 0.4 g of iron/g of poloxamer) and characterized as a prolonged release IM iron supplement. The PTHs had a biocompatible pH for IM injection (6.4) and thermosensitive viscosity, increasing from ∼50 (4 °C) to ∼3000 mPa.s (37 °C). PTHs were successfully injected in the sol state (at 4 °C) into pork meat at 37 °C, transitioning to the gel state in situ (in ∼60-190 s). Structural characterization indicated that there were no PTH-IDP chemical interactions, suggesting that IDP entrapment in PTHs was physical upon gelation. In vitro release studies revealed that iron release from PTH (0.4 g of iron/g of poloxamer) reached 100 % by day 10, whereas 100 % release from FEDEX was complete in 4 h. This novel iron PTH formulation achieved a 60 times long iron release compared to the commercial product. In conclusion, the reported strategy shows adequate IDP entrapment/release properties for prolonged iron release following ex vivo IM injection using biocompatible materials. These results provide a strong basis for future preclinical evaluation to elucidate aspects such as drug release, local irritation, biocompatibility, and efficacy.

Long-acting injectable antiretroviral treatment: experiences of people with HIV and their healthcare providers in Uganda.

INTRODUCTION: Long-acting injectable antiretroviral treatment (LAI-ART) has emerged as a novel alternative to the burden of daily oral pills. The bi-monthly intramuscular injectable containing cabotegravir and rilpivirine holds the promise of improving adherence to ART. The perspectives of potential users of LAI-ART, the majority of whom reside in Eastern and Southern Africa, are still largely unexplored. We set out to understand the experiences of people with HIV (PWH) who received LAI-ART at Fort Portal Regional Referral Hospital in mid-Western Uganda for at least 12 months. METHODS: This qualitative study, conducted between July and August 2023, was nested within a larger study. We conducted four focus groups with 32 (out of 69) PWH who received intramuscular injections of cabotegravir and rilpivirine. In-depth interviews were held with six health workers who delivered LAI-ART to PWH. Data were analyzed by thematic approach broadly modeled on the five domains of the Consolidated Framework for Implementation Research (CFIR). RESULTS: There was high acceptability of LAI-ART (30 /32 or 94%) participants requested to remain on LAI-ART even after the end of the 12-month trial. Adherence to ART was reportedly improved when compared to daily oral treatment. Participants credited LAI-ART with; superior viral load suppression, redemption from the daily psychological reminder of living with HIV, enhanced privacy in HIV care and treatment, reduced HIV-related stigma associated with taking oral pills and that it absolved them from carrying bulky medication packages. Conversely, nine participants reported pain around the injection site and a transient fever soon after administering the injection as side effects of LAI-ART. Missed appointments for receiving the bi-monthly injection were common. Providers identified health system barriers to the prospective scale-up of LAI-ART which include the perceived high cost of LAI-ART, stringent cold chain requirements, physical space limitations, and workforce skills gaps in LAI-ART delivery as potential drawbacks. CONCLUSION: Overall, PWH strongly preferred LAI-ART and expressed a comparatively higher satisfaction with this treatment alternative. Health system barriers to potential scale-up are essential to consider if a broader population of PWH will benefit from this novel HIV treatment option in Uganda and other resource-limited settings. TRIAL REGISTRATION: Trial Registry Number PACTR ID PACTR202104874490818 (registered on 16/04/2021).