Local anaesthetics are essential to regional anaesthesia but may exert neurotoxic effects on peripheral nerves under specific conditions. Although perioperative nerve injury is increasingly recognised, the contribution of local-anaesthetic neurotoxicity, the relative toxicity of different agents and concentrations, and the influence of patient-related risk factors remain incompletely defined. This evidence-based narrative review synthesises experimental and clinical data on peripheral nerve neurotoxicity associated with local anaesthetics and discusses implications for clinical practice and future research. A prospectively registered search was conducted across major biomedical databases for studies published between 1990 and 2024. Experimental evidence consistently demonstrates dose-dependent and time-dependent neurotoxicity for all clinically used local anaesthetics, characterised by ultrastructural damage, oxidative stress, mitochondrial dysfunction and activation of apoptotic and intracellular signalling pathways. Relative toxicity varies between agents and concentrations, with lidocaine and bupivacaine often appearing more potent than ropivacaine or chloroprocaine in preclinical models, while findings for articaine remain heterogeneous. Diabetic and metabolically compromised nerves exhibit increased susceptibility, supporting a 'two-hit' model of injury. In contrast, clinical evidence directly linking specific agents, concentrations or exposure durations to permanent peripheral nerve injury is limited, and such injuries are typically multifactorial. Overall, chemical neurotoxicity should be considered one component of a broader perioperative risk profile. Risk mitigation should prioritise avoidance of intraneural injection, adherence to recommended doses and cautious use of high concentrations or prolonged exposure, particularly in vulnerable nerves. Further research should integrate mechanistic and clinical outcomes while accounting for patient-level risk factors.

Uvular necrosis is an uncommon complication following oesophagogastroduodenoscopy (OGD). We report a case involving a male in his 20s who developed uvular necrosis following a routine OGD performed under conscious sedation. The patient presented three days postprocedure with a worsening sore throat and odynophagia. Examination revealed an erythematous uvula with a necrotic tip. He was managed conservatively with simple analgesia, topical lidocaine and oral antibiotics with eventual full resolution of symptoms with no lasting sequelae. This case highlights a rare yet significant complication of OGD, emphasising the importance of clinician awareness, conservative management and patient reassurance.

Emerging contaminants of concern (CECs) are increasingly detected in tropical riverine systems, yet their prioritization remains challenging due to data gaps, complex mixtures, and limited integration of ecological and human health perspectives. This study proposes an integrated framework to identify priority CECs by combining occurrence data, ecological risk quotients (RQ), human health hazard quotients (HQ), and a novel prioritization index (PI). Thirty-four (34) multiclass CECs, including pharmaceuticals, hormones, and plasticizers, were quantified in four rivers in Johor, Malaysia using optimized solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Caffeine (1511-6085 ng/L), paracetamol (32-7408 ng/L), and bisphenol A (344-837 ng/L) dominated the contaminant profiles. Most pharmaceuticals posed negligible ecological risk, while bisphenol A showed low ecological risk under worst-case exposure (0.01 < RQ < 0.1). In contrast, human health assessment indicated substantial risks from bisphenol A and bisphenol S, particularly for children (HQ > 1). Integration of ecological thresholds (PNEC) and reference doses (RfD) identified bisphenol analogues as highest-priority contaminants, followed by estrone, lidocaine, dexamethasone, and diphenhydramine. The framework demonstrates that concentration-based assessments may underestimate risk and supports toxicity-weighted prioritization for monitoring and regulation in tropical aquatic systems.

Background/Objectives: Local anaesthetic systemic toxicity (LAST) is a rare but potentially fatal complication of dental and oral and maxillofacial surgical local anaesthesia (LA). Three amide agents are commonly used in the UK: lignocaine (lidocaine) 2% with adrenaline 1:80,000; articaine 4% with adrenaline 1:100,000 (2.2 mL cartridges); and bupivacaine 0.5%. Clinically significant discrepancies between guideline sources for maximum recommended dosages (MRDs) persist, and the additive toxicity of combined amide agents remains underappreciated. The objectives are: to provide clear, evidence-appraised MRD guidance for dental practitioners; to explain safe combination dosing using the fractional dose rule with acknowledgement of its pharmacokinetic limitations; and to outline recognition and management of LAST, including intravenous lipid emulsion (ILE) therapy, setting-stratified response, and differential diagnosis. Methods: These include the following: narrative review of MEDLINE (via PubMed), the Cochrane Library, and Embase (inception to May 2026), supplemented by key regulatory documents (British National Formulary (BNF) 91; US Food and Drug Administration (FDA) prescribing information; UK Summaries of Product Characteristics (SmPCs)); major guideline documents (American Society of Regional Anesthesia and Pain Medicine (ASRA) 2018; Association of Anaesthetists 2021; Resuscitation Council UK 2021); systematic reviews; and peer-reviewed literature, ranked by a jurisdiction-specific UK prescribing and regulatory source hierarchy. Results: BNF 91 and the FDA both support a 7 mg/kg (500 mg) MRD for lignocaine with adrenaline; in practice, the adrenaline ceiling limits administration to 6-7 cartridges (2.2 mL) regardless of the guideline followed. The principal reasons for caution when combining amide agents are; additive systemic toxicity, more complex dose calculation, absence of proven clinical benefit for concurrent mixing, unnecessary drug exposure, and incremental hypersensitivity risk-not metabolic pathway differences. The fractional dose rule is a pharmacologically justified safety heuristic with acknowledged pharmacokinetic limitations. ILE is a specific rescue therapy for severe or cardiovascular LAST; airway support and oxygenation remain the primary interventions. Patient-specific factors substantially lower the effective toxic threshold. Conclusions: Safe LA administration in oral surgery requires systematic MRD calculation, application of the fractional dose rule for combined-agent appointments, attention to patient-specific risk factors, setting-appropriate emergency preparedness, and structured differential diagnosis to distinguish LAST from more common dental emergencies.

Fentanyl and its analogs pose considerable dangers to public health and safety, and the development of simple tests that can detect these harmful substances accurately and rapidly could control their currently unchecked spread and thereby safeguard lives. Here, we use systematic evolution of ligands by exponential enrichment (SELEX) to isolate an aptamer that displays a rare blend of high affinity and broad cross-reactivity to 139 fentanyl analogs, alongside excellent specificity against nontarget interferents, including cutting agents, adulterants, and other drugs of abuse. We demonstrate the utility of this aptamer by developing a single-step colorimetric dye-displacement assay that can detect diverse fentanyl analogs within seconds with a simple mix-and-read format. The analog coverage of our assay rivals that of commercial immunoassay-based fentanyl tests while offering better specificity against substances that commonly trigger false positives in those tests, such as diphenhydramine, lidocaine, and methamphetamine. Our findings indicate that aptamers may be fundamentally better suited for achieving broad but specific detection of structurally related classes of molecules relative to other commonly used receptors, such as antibodies, due to their excellent and controllable binding properties, among other benefits, including low cost and high stability.

Aconitine alkaloids, present in herbs like Shengchuanwu and Shengcaowu, are highly cardiotoxic. We describe a rare case of life-threatening aconitine poisoning following the intentional oral ingestion of ``Fufang Jingjie for Fumigation and Washing''-a topical herbal preparation-and highlight the pivotal role of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) as rescue therapy.