Telmisartan-Induced Myotoxicity in Patients with Essential Hypertension.

Drug-related muscular adverse effects are relatively common among certain groups of drugs, such as statins and steroids. However, these adverse effects are less well-known for angiotensin receptor blockers (ARBs). It is proposed that telmisartan and irbesartan may cause myotoxicity via increased Peroxisome Proliferator-Activated Receptor gamma (PPAR-gamma) activity. Herein, we present two hypertensive patients in whom telmisartan-induced myotoxicity was observed. Therefore, physicians should be aware that telmisartan, along with some other ARBs, can also cause myopathy. Possible drug-drug interactions should be considered in cases of concomitant prescription of these agents with other myopathic drugs.

Idebenone ameliorates statin-induced myotoxicity in atherosclerotic ApoE-/- mice by reducing oxidative stress and improving mitochondrial function.

Statins are the first line of choice for the treatment for atherosclerosis, but their use can cause myotoxicity, a common side effect that may require dosage reduction or discontinuation. The exact mechanism of statin-induced myotoxicity is unknown. Previous research has demonstrated that the combination of idebenone and statin yielded superior anti-atherosclerotic outcomes. Here, we investigated the mechanism of statin-induced myotoxicity in atherosclerotic ApoE-/- mice and whether idebenone could counteract it. After administering simvastatin to ApoE-/- mice, we observed a reduction in plaque formation as well as a decrease in their exercise capacity. We observed elevated levels of lactic acid and creatine kinase, along with a reduction in the cross-sectional area of muscle fibers, an increased presence of ragged red fibers, heightened mitochondrial crista lysis, impaired mitochondrial complex activity, and decreased levels of CoQ9 and CoQ10. Two-photon fluorescence imaging revealed elevated H2O2 levels in the quadriceps, indicating increased oxidative stress. Proteomic analysis indicated that simvastatin inhibited the tricarboxylic acid cycle. Idebenone treatment not only further reduced plaque formation but also ameliorated the impaired exercise capacity caused by simvastatin. Our study represents the inaugural comprehensive investigation into the mechanisms underlying statin-induced myotoxicity. We have demonstrated that statins inhibit CoQ synthesis, impair mitochondrial complex functionality, and elevate oxidative stress, ultimately resulting in myotoxic effects. Furthermore, our research marks the pioneering identification of idebenone's capability to mitigate statin-induced myotoxicity by attenuating oxidative stress, thereby safeguarding mitochondrial complex functionality. The synergistic use of idebenone and statin not only enhances the effectiveness against atherosclerosis but also mitigates statin-induced myotoxicity.

Follow-up of Serum Creatine Phosphokinase Levels after Ultrasound Guided Suprainguinal Fascia Iliaca Block with Bupivacaine in Total Knee Arthroplasty Patients: An Observational, Controlled Study.

OBJECTIVE: To determine the myotoxicity of bupivacaine on muscles after suprainguinal fascia iliaca block for postoperative analgesia in total knee arthroplasty (TKA) patients through changes in serum creatine phosphokinase (CPK) levels during the perioperative period. STUDY DESIGN: Observational study. Place and Duration of the Study: Postoperative Recovery Room department of Anaesthesiology and Reanimation, Samsun University, Samsun, Training and Research Hospital, Samsun, Turkiye, between December 2022 and February 2023. METHODOLOGY: Patients undergoing for the procedure of TKA surgery were recruited. (40 controls and 42 SIFIB groups). Serum CPK levels were evaluated preoperatively, at postoperative 6th hour and 24th hour. RESULTS:  From total 82 patients, 42 of them who received SIFIB as a component of multimodal analgesia had serum CPK levels comparable to those in the control group at all time points (p>0.05). While the increase in CPK level at 6th hour relative to baseline was significant in both groups (p<0.05), only the block group demonstrated a statistically significant difference between the 6th and 24th hours (p<0.05). CONCLUSION: SIFIB administration did not result in severe bupivacaine-induced myotoxicity in comparison to the control group. SIFIB administration is a safe option when used as part of multimodal analgesia in TKA. KEY WORDS:  Bupivacaine, Creatine phosphokinase, Myotoxicity, Regional anaesthesia.

Viper Venom Phospholipase A2 Database: The Structural and Functional Anatomy of a Primary Toxin in Envenomation.

Viper venom phospholipase A2 enzymes (vvPLA2s) and phospholipase A2-like (PLA2-like) proteins are two of the principal toxins in viper venom that are responsible for the severe myotoxic and neurotoxic effects caused by snakebite envenoming, among other pathologies. As snakebite envenoming is the deadliest neglected tropical disease, a complete understanding of these proteins' properties and their mechanisms of action is urgently needed. Therefore, we created a database comprising information on the holo-form, cofactor-bound 3D structure of 217 vvPLA2 and PLA2-like proteins in their physiologic environment, as well as 79 membrane-bound viper species from 24 genera, which we have made available to the scientific community to accelerate the development of new anti-snakebite drugs. In addition, the analysis of the sequenced, 3D structure of the database proteins reveals essential aspects of the anatomy of the proteins, their toxicity mechanisms, and the conserved binding site areas that may anchor universal interspecific inhibitors. Moreover, it pinpoints hypotheses for the molecular origin of the myotoxicity of the PLA2-like proteins. Altogether, this study provides an understanding of the diversity of these toxins and how they are conserved, and it indicates how to develop broad, interspecies, efficient small-molecule inhibitors to target the toxin's many mechanisms of action.

A Bite by Shaw's Short Sea Snake (Hydrophis curtus): A Case of Mild Myotoxicity or a Dry Bite?

Although sea snakes (Elapidae) are commonly encountered by fishermen, accurately authenticated envenomings by them are uncommon in clinical literature. We report an authenticated case of Shaw's short, or spine-bellied, sea snake (Hydrophis curtus) bite in a young fisherman from northern Sri Lanka. The patient had clinical and biochemical evidence of mild transient myotoxicity but no evidence of neuromuscular paralysis or significant renal injury. Consideration of the clinical manifestations suggests either a mild envenoming or a dry bite. The patient completely recovered without any antivenom therapy and was discharged on the fourth day. Prolonged observation may be beneficial to exclude complications of sea snake envenoming.

Plants Causing Toxic Myopathies.

Boxelder and sycamore maple contain hypoglycin A (HGA), the toxic metabolite of which, MCPA-CoA, inhibits fatty acid ß-oxidation, causing seasonal pasture myopathy (SPM) or atypical myopathy (AM), respectively. White snakeroot and rayless goldenrod contain multiple benzofuran ketones (BFKs). The identity/toxicity of BFKs appear variable, possibly involving interactions between toxins/toxic metabolites, but ultimately inhibit cellular energy metabolism. Unthrifty horses grazing sparse pastures during the fall appear predisposed to these plant-associated, frequently fatal, toxic myopathies. Toxidromes are characterized by varying degrees of rhabdomyolysis and cardiac myonecrosis, with plant toxins remaining toxic in hay and being excreted in milk.

Regular exercise attenuates alcoholic myopathy in zebrafish by modulating mitochondrial homeostasis.

Alcoholic myopathy is caused by chronic consumption of alcohol (ethanol) and is characterized by weakness and atrophy of skeletal muscle. Regular exercise is one of the important ways to prevent or alleviate skeletal muscle myopathy. However, the beneficial effects and the exact mechanisms underlying regular exercise on alcohol myopathy remain unclear. In this study, a model of alcoholic myopathy was established using zebrafish soaked in 0.5% ethanol. Additionally, these zebrafish were intervened to swim for 8 weeks at an exercise intensity of 30% of the absolute critical swimming speed (Ucrit), aiming to explore the beneficial effects and underlying mechanisms of regular exercise on alcoholic myopathy. This study found that regular exercise inhibited protein degradation, improved locomotion ability, and increased muscle fiber cross-sectional area (CSA) in ethanol-treated zebrafish. In addition, regular exercise increases the functional activity of mitochondrial respiratory chain (MRC) complexes and upregulates the expression levels of MRC complexes. Regular exercise can also improve oxidative stress and mitochondrial dynamics in zebrafish skeletal muscle induced by ethanol. Additionally, regular exercise can activate mitochondrial biogenesis and inhibit mitochondrial unfolded protein response (UPRmt). Together, our results suggest regular exercise is an effective intervention strategy to improve mitochondrial homeostasis to attenuate alcoholic myopathy.

Thymus alterations and susceptibility to immune checkpoint inhibitor myocarditis.

Immune checkpoint inhibitors (ICI) have transformed the therapeutic landscape in oncology. However, ICI can induce uncommon life-threatening autoimmune T-cell-mediated myotoxicities, including myocarditis and myositis. The thymus plays a critical role in T cell maturation. Here we demonstrate that thymic alterations are associated with increased incidence and severity of ICI myotoxicities. First, using the international pharmacovigilance database VigiBase, the Assistance Publique Hôpitaux de Paris-Sorbonne University data warehouse (Paris, France) and a meta-analysis of clinical trials, we show that ICI treatment of thymic epithelial tumors (TET, and particularly thymoma) was more frequently associated with ICI myotoxicities than other ICI-treated cancers. Second, in an international ICI myocarditis registry, we established that myocarditis occurred earlier after ICI initiation in patients with TET (including active or prior history of TET) compared to other cancers and was more severe in terms of life-threatening arrythmias and concurrent myositis, leading to respiratory muscle failure and death. Lastly, we show that presence of anti-acetylcholine-receptor antibodies (a biological proxy of thymic-associated autoimmunity) was more prevalent in patients with ICI myocarditis than in ICI-treated control patients. Altogether, our results highlight that thymic alterations are associated with incidence and seriousness of ICI myotoxicities. Clinico-radio-biological workup evaluating the thymus may help in predicting ICI myotoxicities.

Daptomycin Exposure as a Risk Factor for Daptomycin-Induced Eosinophilic Pneumonia and Muscular Toxicity.

BACKGROUND: High-dose daptomycin is increasingly used in patients with bone and joint infection (BJI). This raises concerns about a higher risk of adverse events (AEs), including daptomycin-induced eosinophilic pneumonia (DIEP) and myotoxicity. We aimed to examine pharmacokinetic and other potential determinants of DIEP and myotoxicity in patients with BJI receiving daptomycin. METHODS: All patients receiving daptomycin for BJI were identified in a prospective cohort study. Cases were matched at a 1:3 ratio, with controls randomly selected from the same cohort. Bayesian estimation of the daptomycin daily area under the concentration-time curve over 24 hours (AUC24h) was performed with the Monolix software based on therapeutic drug monitoring (TDM) data. Demographic and biological data were also collected. Risk factors of AEs were analyzed using Cox proportional hazards model. RESULTS: From 1130 patients followed over 7 years, 9 with DIEP, 26 with myotoxicity, and 106 controls were included in the final analysis. Daptomycin AUC24h, C-reactive protein, and serum protein levels were associated with the risk of AEs. The adjusted hazard ratio of DIEP or myotoxicity was 3.1 (95% confidence interval [CI], 1.48-6.5; P < .001) for daptomycin AUC24h > 939 mg/h/L, 9.8 (95% CI, 3.94-24.5; P < .001) for C-reactive protein > 21.6 mg/L, and 2.4 (95% CI, 1.02-5.65; P = .04) for serum protein <72 g/L. CONCLUSIONS: We identified common determinants of DIEP and myotoxicity in patients with BJI. Because the risk of AEs was associated with daptomycin exposure, daptomycin TDM and model-informed precision dosing may help optimize the efficacy and safety of daptomycin treatment in this setting. A target AUC24h range of 666 to 939 mg/h/L is suggested.

Cardiomyocytes, sphingolipids and cardio myotoxicity.

PURPOSE OF REVIEW: Sphingolipids are structurally diverse membrane lipids localized in lipid bilayers. Sphingolipids are not only important structural components of cellular membranes, but they are also important regulators of cellular trafficking and signal transduction and are implicated in several diseases. Here, we review the latest insights into sphingolipids and their role in cardiac function and cardiometabolic disease. RECENT FINDINGS: The underlying mechanisms linking sphingolipids to cardiac dysfunction are still not fully clarified. Sphingolipids, and in particular ceramides, have emerged as important players in lipotoxicity, mediating inflammation, impaired insulin signalling and apoptosis. In addition, recent findings highlight the importance of glycosphingolipid homeostasis in cardiomyocyte membranes, where they are required to maintain ß-adrenergic signalling and contractile capacity to preserve normal heart function. Thus, glycosphingolipid homeostasis in cardiac membranes characterizes a novel mechanism linking sphingolipids to cardiac disease. SUMMARY: Modulation of cardiac sphingolipids may represent a promising therapeutic approach. Sustained investigation of the link between sphingolipids and cardiomyocyte function is therefore needed and we hope that this review may inspire researchers to further elucidate the action of these lipids.

Ascorbic acid reduces Ropivacaine-induced myotoxicity in cultured human osteoporotic skeletal muscle cells.

BACKGROUND: Osteoporosis is a worldwide health issue. Loss of bone mass is a potential risk factor for fragility fractures, and osteoporotic fractures place a considerable burden on society. Bone and muscle represent a functional unit in which the two tissues are intimately interconnected. Ropivacaine is a potent local anesthetic used in clinical practice for intraoperative anesthesia and postoperative pain management, in particular for hip surgery. When injected, Ropivacaine can diffuse locally through, in particular in surrounding skeletal muscle tissue, causing dose-dependent cytotoxicity, oxidative stress and myogenesis impairment. Based on those evidences, we focused our attention on Ropivacaine-induced cytotoxicity on cultured human myoblasts. METHODS: Primary human myoblasts and myotubes from healthy subjects, osteoarthritic and osteoporotic patients (OP) were cultured in the presence of Ropivacaine. In some experiments, ascorbic acid (AsA) was added as a potent antioxidant agent. Cell viability and ROS levels were evaluated to investigate the myotoxic activity and Real-Time PCR and Western blot analysis carried out to investigate the expression of proliferation and myogenic markers. RESULTS: A dose-dependent decrease of cell viability was observed after Ropivacaine exposure in both OP myoblasts and myotubes cultures, whereas those effects were not observed in the presence of Propofol, a general anesthetic. The adding of AsA reduced Ropivacaine negative effects in OP myoblast cultures. In addition, Ropivacaine exposure also increased ROS levels and upregulated Nox4 expression, an enzyme primarily implicated in skeletal muscle ROS generation. AsA treatment counteracted the oxidant activity of Ropivacaine and partially restored the basal condition in cultures. Positive myogenic markers, such as MyoD and Myf5, were downregulated by Ropivacaine exposure, whereas myostatin, a negative regulator of muscle growth and differentiation, was upregulated. The phenotypic deregulation of myogenic controllers in the presence of Ropivacaine was counteracted by AsA treatment. CONCLUSIONS: Our findings highlight the oxidative stress-mediated myotoxic effect of Ropivacaine on human skeletal muscle tissue cell cultures, and suggest treatment with AsA as valid strategy to mitigate its negative effects and allowing an ameliorated functional skeletal muscle recovery in patients undergoing hip replacement surgery for osteoporotic bone fracture.

Benzonatate as a local anesthetic.

INTRODUCTION: Benzonatate is an FDA-approved antitussive agent that resembles tetracaine, procaine, and cocaine in its chemical structure. Based on structural similarities to known local anesthetics and recent findings of benzonatate exerting local anesthetic-like effects on voltage-gated sodium channels in vitro, we hypothesized that benzonatate will act as a local anesthetic to yield peripheral nerve blockade. METHODS: Benzonatate was injected at the sciatic nerve of Sprague-Dawley rats. Sensory and motor blockade were assessed using a modified hot plate test and a weight-bearing test, respectively. Additionally, the effect of co-injection with tetrodotoxin and Tween 80 (a chemical permeation enhancer) was examined. Myotoxicity of benzonatate was assessed in vivo by histological analysis. RESULTS: Benzonatate produced a concentration-dependent sensory and motor nerve blockade with no appreciable systemic effects. Co-injection with tetrodotoxin or Tween 80 produced prolongation of sensory nerve blockade. Histologic assessment showed significant inflammation and myotoxicity from benzonatate injection, even at low concentrations. CONCLUSION: This study demonstrates that benzonatate does act as a local anesthetic at the peripheral nerve, with sensory and motor nerve blockade. Benzonatate interacts with tetrodotoxin and Tween 80 to prolong nerve blockade. However, benzonatate causes significant myotoxicity, even at subtherapeutic concentrations.

Impact of porous microsponges in minimizing myotoxic side effects of simvastatin.

Simvastatin (SV) is a poorly soluble drug; its oral administration is associated with a significant problem: Myopathy. The present study aims to formulate SV microsponges that have the potential to minimize the myotoxicity accompanying the oral administration of the drug. SV microsponges were prepared by exploiting the emulsion solvent evaporation technique. The % entrapment efficiency (%EE) of the drug approached 82.54 ± 1.27%, the mean particle size of SV microsponges ranged from 53.80 ± 6.35 to 86.03 ± 4.79 µm in diameter, and the % cumulative drug release (%CDR) of SV from microsponges was significantly higher than that from free drug dispersion much more, the specific surface area of the optimized microsponges formulation was found to be 16.6 m2/g revealed the porosity of prepared microsponges. Histological and glycogen histochemical studies in the skeletal muscles of male albino rats revealed that microsponges were safer than free SV in minimizing myotoxicity. These findings were proven by Gene expression of Mitochondrial fusion and fission (Mfn1) & (Fis1) and (Peroxisome proliferator-activated receptor gamma co-activator 1α) PGC-1α. Finally, our study ascertained that SV microsponges significantly decreased the myotoxicity of SV.

Concomitant use of statins and sodium-glucose co-transporter 2 inhibitors and the risk of myotoxicity reporting: A disproportionality analysis.

AIMS: Recent case reports have suggested that sodium-glucose co-transporter 2 (SGLT2) inhibitors may interact with statins to increase their risk of myotoxicity. We assessed the risk of myotoxicity reporting associated with concomitant use of SGLT2 inhibitors and statins. METHODS: We queried the US Food and Drug Administration Adverse Event Reporting System (FAERS) from 2013 to 2021 for reports including SGLT2 inhibitors, statins or both. We estimated several measures of disproportionate reporting of myopathy and rhabdomyolysis associated with concomitant use of SGLT2 inhibitors and statins: reporting odds ratio (ROR) with 95% confidence interval (CI), Ω shrinkage measure (safety signal if >0) and an extension of the proportional reporting ratio (PRR) (two-criteria set, safety signal if both criteria are met), using the full FAERS dataset as the reference set. In sensitivity analyses, we focussed on specific SGLT2 inhibitor-statin pairs with higher interaction potential (canagliflozin-rosuvastatin, empagliflozin-rosuvastatin) and accounted for stimulated reporting. RESULTS: There were 456 myopathy and 77 rhabdomyolysis reports involving both an SGLT2 inhibitor and a statin. Concomitant use of SGLT2 inhibitors and statins was not associated with an increased risk of myopathy (ROR 0.79, 95% CI 0.70 to 0.89) or rhabdomyolysis (ROR 0.58, 95% CI 0.41 to 0.83) reporting. For both outcomes, the Ω shrinkage measure was negative and only one criterion of the PRR extension was met. SGLT2 inhibitor-statin pairs with higher interaction potential yielded potential signals for rhabdomyolysis; these signals disappeared after accounting for stimulated reporting. CONCLUSION: There was no increased risk of myotoxicity reporting associated with concomitant use of SGLT2 inhibitors and statins or for specific drug pairs.

Adverse effects of systemic cancer therapy on skeletal muscle: myotoxicity comes out of the closet.

PURPOSE OF REVIEW: Systemic cancer therapy-associated skeletal muscle wasting is emerging as a powerful impetus to the overall loss of skeletal muscle experienced by patients with cancer. This review explores the clinical magnitude and biological mechanisms of muscle wasting during systemic cancer therapy to illuminate this adverse effect. Emerging strategies for mitigation are also discussed. RECENT FINDINGS: Clinical findings include precise, specific measures of muscle loss over the course of chemotherapy, targeted therapy and immunotherapy. All these therapeutic classes associate with quantitatively important muscle loss, independent of tumor response. Parallel experimental studies provide understanding of the specific molecular basis of wasting, which can include inhibition of protein synthesis, proliferation and differentiation, and activation of inflammation, reactive oxygen species, autophagy, mitophagy, apoptosis, protein catabolism, fibrosis and steatosis in muscle. Strategies to mitigate these muscle-specific adverse effects of cancer therapy remain in the earliest stages of development. SUMMARY: The adverse side effect of cancer therapy on skeletal muscle has been largely ignored in the development of cancer therapeutics. Given the extent to which loss of muscle mass and function can bear on patients' function and quality of life, protection/mitigation of these side effects is a research priority.

Abatacept/Ruxolitinib and Screening for Concomitant Respiratory Muscle Failure to Mitigate Fatality of Immune-Checkpoint Inhibitor Myocarditis.

Immune-checkpoint-inhibitor (ICI)-associated myotoxicity involves the heart (myocarditis) and skeletal muscles (myositis), which frequently occur concurrently and are highly fatal. We report the results of a strategy that included identification of individuals with severe ICI myocarditis by also screening for and managing concomitant respiratory muscle involvement with mechanical ventilation, as well as treatment with the CTLA4 fusion protein abatacept and the JAK inhibitor ruxolitinib. Forty cases with definite ICI myocarditis were included with pathologic confirmation of concomitant myositis in the majority of patients. In the first 10 patients, using recommended guidelines, myotoxicity-related fatality occurred in 60%, consistent with historical controls. In the subsequent 30 cases, we instituted systematic screening for respiratory muscle involvement coupled with active ventilation and treatment using ruxolitinib and abatacept. The abatacept dose was adjusted using CD86 receptor occupancy on circulating monocytes. The myotoxicity-related fatality rate was 3.4% (1/30) in these 30 patients versus 60% in the first quartile (P < 0.0001). These clinical results are hypothesis-generating and need further evaluation. SIGNIFICANCE: Early management of respiratory muscle failure using mechanical ventilation and high-dose abatacept with CD86 receptor occupancy monitoring combined with ruxolitinib may be promising to mitigate high fatality rates in severe ICI myocarditis. See related commentary by Dougan, p. 1040. This article is highlighted in the In This Issue feature, p. 1027.

The Management of Hypercholesterolemia in Patients with Neuromuscular Disorder.

PURPOSE OF REVIEW: We describe and discuss the safety of statins and non-statin drugs in neuromuscular disorders (NMDs). We also propose a pragmatic model of care for the management of such cases. RECENT FINDINGS: Patients with both NMD and hypercholesterolemia may be particularly disadvantaged owing to the toxic effects of cholesterol-lowering therapy and the inability to take medication. Specifically, the management of hypercholesterolemia in patients with NMD is complicated by the increased risk of statin-related myotoxicity and concerns that statins may aggravate or possibly induce the onset of a specific NMD. The most severe form of statin-related myotoxicity is immune-mediated necrotizing myopathy. Management of hypercholesterolemia in patients with NMDs include treating modifiable factors, consideration of toxicity risk of statin, use of non-statin lipid lowering agents, noting possible drug interactions, and careful monitoring.

The early inhibition of the COX-2 pathway in viperid phospholipase A2-induced skeletal muscle myotoxicity accelerates the tissue regeneration.

The administration of non-steroidal anti-inflammatory drugs in the treatment of injury and muscle regeneration is still contradictory in effectiveness, especially regarding the timing of their administration. This can interfere with the production of prostaglandins originating from inflammatory isoform cyclooxygenase-2 (COX-2), which is essential to modulate tissue regeneration. The phospholipases A2 (PLA2) from viperid venoms cause myotoxicity, therefore constituting a tool for the study of supportive therapies to improve skeletal muscle regeneration. This study investigated the effect of early administration of lumiracoxib (selective inhibitor of COX-2) on the degeneration and regeneration stages of skeletal muscle after injury induced by a myotoxic PLA2. After 30 min and 48 h of intramuscular injection of PLA2, mice received lumiracoxib orally and histological, functional, and transcriptional parameters of muscle were evaluated from 6 h to 21 days. Inhibition of COX-2 in the early periods of PLA2-induced muscle degeneration reduced leukocyte influx, edema, and tissue damage. After the second administration of lumiracoxib, in regenerative stage, muscle showed increase in number of basophilic fibers, reduction in fibrosis content and advanced recovery of functionality characterized by the presence of fast type II fibers. The expression of Pax7 and myogenin were increased, indicating a great capacity for storing satellite cells and advanced mature state of tissue. Our data reveals a distinct role of COX-2-derived products during muscle degeneration and regeneration, in which early administration of lumiracoxib was a therapeutic strategy to modulate the effects of prostaglandins, providing a breakthrough in muscle tissue regeneration induced by a myotoxic PLA2.

Bothrops atrox mice experimental envenoming treatment using light-emitting diode (led) as an adjunct therapy to conventional serum therapy.

The use of anti-venom is one of the main control measures for snakebite envenoming when applied immediately after the snakebite. Systemic effects of the envenoming are usually reversed; however, neutralization of local effects is hardly achieved. The need for adjuvant therapies associated with serum therapy can improve the treatment for local effects of envenoming, with greater effectiveness in preventing or delaying the progression of damage, reducing the clinical signs and symptoms of victims of snakebites. The purpose of the study was to evaluate the photobiomodulation therapy using LED and/or dexamethasone associated with conventional serum therapy for the treatment of local damage caused by Bothrops atrox envenomation in a murine model. For this, experimental envenoming was carried out in the gastrocnemius muscle of male Swiss mice weighing 18 to 22 g divided into 8 groups of animals, distributed in groups non-treat, treated with anti-bothropic serum, dexamethasone, and LED, or the associated treatments, by intramuscular inoculation of 50 µg of venom or sterile PBS (control). After 30 min, the proposed treatments were administered alone or in combination. After 3 h, blood and muscle samples were collected for myotoxicity, cytotoxicity, histological analysis, and IL-1ß assays. The evaluation of the treatment alone showed that serum therapy is not effective for the treatment of local damage and photobiomodulation demonstrated to be an effective therapy to reduce leukocyte infiltration, hemorrhage, and myotoxicity in experimental envenoming; dexamethasone proved to be a good resource for the treatment of the inflammatory process reducing the leukocyte infiltration. The association of serum therapy, LED, and dexamethasone was the best treatment to reduce the local effects caused by Bothrops atrox venom. All in all, the association of photobiomodulation therapy using LED with conventional serum therapy and the anti-inflammatory drug is the best treatment for reducing the undesirable local effects caused by snakebite accidents involving B. atrox species.