Antivenin Therapy Research Articles

Wound Infections of Snakebites from the Venomous Protobothrops mucrosquamatus and Viridovipera stejnegeri in Taiwan: Bacteriology, Antibiotic Susceptibility, and Predicting the Need for Antibiotics-A BITE Study.

Snakebites from Taiwan habus (Protobothrops mucrosquamatus) and green bamboo vipers (Viridovipera stejnegeri) account for two-thirds of all venomous snakebites in Taiwan. While there has been ongoing optimization of antivenin therapy, the proper management of superimposed bacterial wound infections is not well studied. In this Bacteriology of Infections in Taiwanese snake Envenomation (BITE) study, we investigated the prevalence of wound infection, bacteriology, and corresponding antibiotic usage in patients presenting with snakebites from these two snakes. We further developed a BITE score to evaluate the probability of wound infections and guide antibiotic usage in this patient population. All snakebite victims who presented to the emergency departments of seven training and research hospitals and received at least one vial of freeze-dried hemorrhagic antivenin between January 2001 and January 2017 were identified. Patient biodata, laboratory investigation results, and treatment modalities were retrieved. We developed our BITE score via univariate and multiple logistic regression analyses. The receiver operating characteristic (ROC) curve was plotted to evaluate the predictive performance of the BITE score. Out of 8,295,497 emergency department visits, 726 patients presented with snakebites from a Taiwan habu or a green bamboo viper. The wound infection rate was 22.45%, with seven positive wound cultures, including six polymicrobial infections. Morganella morganii, Enterococcus spp., Bacteroides fragilis, and Aeromonas hydrophila were most frequently cultured. There were no positive blood cultures. A total of 33.0% (n = 106) of snakebite patients who received prophylactic antibiotics nevertheless developed wound infections, while 44.8% (n = 73) of wound infection patients were satisfactorily treated with one of the following antibiotics: amoxicillin/clavulanic acid, oxacillin, cefazolin, and ampicillin/sulbactam. With the addition of gentamicin, the success of antibiotic therapy increased by up to 66.54%. The prognostic factors for the secondary bacterial infection of snakebites were white blood cell counts, the neutrophil lymphocyte ratio, and the need for hospital admission. The area under the ROC curve for the BITE score was 0.839. At the optimal cut-off point of 5, the BITE score had a 79.58% accuracy, 82.31% sensitivity, and 79.71% specificity when predicting infection in snakebite patients. Our BITE score may help with antibiotic stewardship by guiding appropriate antibiotic use in patients presenting with snakebites. It may also be employed in further studies into antibiotic prophylaxis in snakebite patients for the prevention of superimposed bacterial wound infections.

Envenomation by an arachnid (Latrodectus or Steatoda): Case report involving a woman and her female dog

Introduction: Accidents involving spiders bites usually cause mild medical reactions that lead to local symptoms and, less commonly, systemic effects. The most medically significant spiders belong to the genera Latrodectus and Loxosceles. This paper presents a posible case of steatodism in a young woman and her pet.Case description: 26-year-old female patient, who reports a clinical history characterized by paresthesia, malaise, fever, diarrea and a painful papule in the left cheek after being bitten by a spider. Immediately after being bit, the patient hit the spider with the back of her hand and it fell to the ground, where her dog swallowed it. The dog presented with vomiting and general discomfort after ingestion. Symptomatic therapy was given for comfort, and neither the patient nor the dog required antivenin therapy. Both evolved favorably.Discussion: The relevance of this case is the involvement of two mammals (a human and her dog) due to the accidental contact with a spider, possibly of the genus Latrodectus or Steatoda.Conclusion: Two possible cases of steatodism are described. Since spider bites are a relatively frequent reason for medical consultation in Colombia, it is important to diagnose and manage them properly.

Resource Utilization After Snakebite Severity Score Implementation into Treatment Algorithm of Crotaline Bite

BackgroundCrotaline envenomation clinical manifestations vary considerably among patients. Current recommendations for treatment with Crotalidae polyvalent immune Fab require assessment of envenomation control. Determining control of envenomation, particularly when patients are evaluated by different providers in separate clinical settings, can be difficult. ObjectiveTo determine if a difference in total vials of Crotalidae antivenin therapy exists between pre-protocol and post-Snakebite Severity Score (SSS) protocol. MethodsRetrospective medical record review at an academic medical and regional Level I trauma center. Resource utilization in patients with a diagnosis of “snakebite” was compared between patients treated pre- and post-SSS protocol implementation. ResultsOne hundred forty-six patients were included in the evaluation. One hundred twenty-seven (87.0%) patients received antivenin, n = 80 (90.9%) in the pre-protocol group and n = 47 (81.0%) in the post-protocol group. Median total number of antivenin vials per patient was lower in the post-protocol group than the pre-protocol group, 16 (10–24 interquartile range) vs. 12 (10–16 interquartile range), p = 0.006. This decreased utilization correlates to an approximate $13,200 savings per patient. Hospital and intensive care unit length of stay, opioid use, incidence of blood product transfusion, need for surgical intervention, or need for intubation were not different between groups. ConclusionsA snakebite protocol with SSS utilization to guide antivenin administration results in significantly decreased antivenin therapy in snakebite patients without increase in other health care utilization.

The Related Risk Factors Analysis of Snake-Bite Induced Acute Kidney Injury.

BackgroundThe pathogenic mechanism of snake-bite induced acute kidney injury (AKI) remains unclear. Analyzing the risk factors for snake-bite induced AKI may provide the guidance needed for AKI prevention and early treatment.Material/MethodsThis retrospective study included 119 snake-bite patients who were hospitalized at the emergency department of Sichuan Provincial People’s Hospital from January 2011 to September 2013. The patients were divided into AKI and non-AKI groups according to the 2012 Kidney Disease: Improving Global Outcomes (KDIGO) guideline. Gender, age, and clinical examination data of the patients were recorded. The Mann-Whitney U test and Fisher exact test were performed to analyze the collected data; preliminary analysis of independent risk factors was performed with multivariate logistic regression.ResultsAmong the snake-bite patients, 98.3% were farmers. The mean age of patients was 46±12 years. Of the 119 patients (13.4%), 16 suffered from AKI. There were statistically significant differences between the AKI and non-AKI groups with respect to age, time interval from snake bite to antivenin therapy, creatine kinase, blood myoglobin, advanced age, regional lymphadenopathy, incision drainage, and hemoglobin. Preliminary analysis with multivariate logistic regression showed that advanced age and increased time interval from snake bite to antivenin therapy might be independent risk factors for snake-bite induced AKI.ConclusionsAge, time interval from snake bite to antivenin therapy, creatine kinase, blood myoglobin, advanced age, regional lymphadenopathy, incision drainage, and hemoglobin were risk factors for snake-bite induced AKI. Advanced age and delayed antivenin therapy might be independent risk factors for snake-bite induced AKI.

Propensity of crocin to offset Vipera russelli venom induced oxidative stress mediated neutrophil apoptosis: a biochemical insight.

Viper envenomation results in inflammation at the bitten site as well as target organs. Neutrophils and other polymorphonuclear leukocytes execute inflammation resolving mechanism and will undergo apoptosis after completing the task. However, the target specific toxins induce neutrophil apoptosis at the bitten site and in circulation prior to their function, thus reducing their number. Circulating activated neutrophils are major source of inflammatory cytokines and leakage of reactive oxygen species (ROS)/other toxic intermediates resulting in aggravation of inflammatory response at the bitten/target site. Therefore, neutralization of venom induced neutrophil apoptosis reduces inflammation besides increasing the functional neutrophil population. Therefore, the present study investigates the venom induced perturbances in isolated human neutrophils and its neutralization by crocin (Crocus sativus) a potent antioxidant carotenoid. Human neutrophils on treatment with venom resulted in altered ROS generation, intracellular Ca(2+) mobilization, mitochondrial membrane depolarization, cyt-c translocation, caspase activation, phosphatidylserine externalization and DNA damage. On the other hand significant protection against oxidative stress and apoptosis were evidenced in crocin pre-treated groups. In conclusion the viper venom induces neutrophil apoptosis and results in aggravation of inflammation and tissue damage. The present study demands the necessity of an auxiliary therapy in addition to antivenin therapy to treat secondary/overlooked complications of envenomation.

Melatonin alleviates Echis carinatus venom‐induced toxicities by modulating inflammatory mediators and oxidative stress

Viper bites cause high morbidity and mortality worldwide and regarded as a neglected tropical disease affecting a large healthy population. Classical antivenom therapy has appreciably reduced the snakebite mortality rate; it apparently fails to tackle viper venom-induced local manifestations that persist even after the administration of antivenom. Recently, viper venom-induced oxidative stress and vital organ damage is deemed as yet another reason for concern; these are considered as postmedicated complications of viper bite. Thus, treating viper bite has become a challenge demanding new treatment strategies, auxiliary to antivenin therapy. In the last decade, several studies have reported the use of plant products and clinically approved drugs to neutralize venom-induced pharmacology. However, very few attempts were undertaken to study oxidative stress and vital organ damage. Based on this background, the present study evaluated the protective efficacy of melatonin in Echis carinatus (EC) venom-induced tissue necrosis, oxidative stress, and organ toxicity. The results demonstrated that melatonin efficiently alleviated EC venom-induced hemorrhage and myonecrosis. It also mitigated the altered levels of inflammatory mediators and oxidative stress markers of blood components in liver and kidney homogenates, and documented renal and hepatoprotective action of melatonin. The histopathology of skin, muscle, liver, and kidney tissues further substantiated the overall protection offered by melatonin against viper bite toxicities. Besides the inability of antivenoms to block local effects and the fact that melatonin is already a widely used drug promulgating a multitude of therapeutic functionalities, its use in viper bite management is of high interest and should be seriously considered.

Viper venom-induced oxidative stress and activation of inflammatory cytokines: a therapeutic approach for overlooked issues of snakebite management

The snakebite mortality rate has been significantly reduced due to effective anti-venin therapy. The intravenously infused anti-venom will neutralize free and target-bound toxins but fails to neutralize venom-induced inflammation and oxidative stress, as the antigen-antibody complex itself is pro-inflammatory. Therefore, an auxiliary therapy is necessary to treat secondary/overlooked envenomation complications. Blood samples from healthy donors were treated with viper venom (100 μg/ml) for 2 h. The venom-induced inflammation, oxidative damage and effect of crocin pre-treatment were determined by assessing the serum levels of cytoplasmic, lysosomal and oxidative stress markers along with pro-inflammatory mediators such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and cyclo-oxygenase (COX)-2. Significantly increased stress markers, cytoplasmic, lysosomal and extracellular matrix-degrading enzymes as well as the pro-inflammatory mediators TNF-α, IL-1β, IL-6 and COX-2 indicated increased cellular damage but significantly reduced oxidative damage and inflammation in crocin pre-treated groups. The data clearly suggest that venom-induced oxidative stress and inflammation is also responsible for oxidative burst and cell death in the circulation, which may worsen even after anti-venin therapy. Hence, the current study demands a supportive therapy in addition to anti-venin therapy to neutralize the overlooked issues of snakebite.

Scorpion Anti-Venom Activity of Botanicals: A Pharmacological Approach

Scorpion bite is considered as one of the common and dangerous phenomenon throughout the world. The clinical manifestations include pulmonary edema, myocardial damage, intracerebral haemorrhage, brachial plexopathy, renal failure etc. which sometimes leads to mortality. The common antivenin therapy includes anti-scorpion venom serum or prazosin. In the vast rural areas of the third world countries phytotherapy is considered as an alternative system of medicine and scorpion sting is treated with the help of medicinal botanicals. As the safety and efficacy are considered as important aspects of anti venin therapy, conventional treatment can be supported by the herbal remedy. The present review compiles a number of medicinal plants pharmacologically evaluated in vitro and/or in vivo for scorpion antivenin properties. Considering the aspects like cost effectiveness, availability, lesser side effects and development of drug resistance, plant based anti venin therapy may be considered as a possible remedy against scorpion envenomation.

Antihaemolytic and snake venom neutralizing effect of some Indian medicinal plants

Objective To validate traditional claims of usefulness of the Indian plants in management of poisonous snakebite and evaluate the antivenom properties displayed by the alcoholic extracts of Andrographis paniculata ( A. paniculata), Crateva magna ( C. magna), Gloriosa superba ( G. superba) and Hydrocotyle javanica ( H. javanica). Methods These plants were collected, identified and the extracts were prepared by using conventional Soxhlet ethanol extraction technique. The venom neutralization activity was accessed in mice (20-25g) and number of mortalities was observed against clinically important snake (Naja nigricollis) venom. Present study also deals with in vitro membrane stabilizing activity of these plants against hyposaline induced human red blood corpuscles (HRBC). Results Extracts of H. javanica and G. superba gave 80 % and 90 % protection to mice treated with minimum lethal dose of venom (LD 99). These two plants showed significant neutralization effect against the venoms of Naja nigricollis venom. H. javanica and G. superba (25-100 mg/mL) produced significant changes of membrane stabilization of human red blood cells (HRBC) exposed to hyposaline-induced haemolysis. Conclusions We conclude that probably due to presence of various phytochemicals plays an important role in the anti-venom potential of these Indian medicinal plants against Naja nigricollis venom. The above observations confirmed that A. paniculata, C. magna, G. superba and H. javanica plant extracts possess potent snake venom neutralizing capacity and could potentially be used as an adjuvants for antivenin therapy in case of snakebite envenomation, especially against the local effects of cobra venoms.

Cardiac Tamponade in Russell Viper (Daboia russelii) Bite: Case Report with Brief Review

BackgroundCoagulopathy after snake bite is well known; however, cardiac tamponade as a manifestation of coagulopathy is rare. ObjectiveTo report a case of pericardial hemorrhage with cardiac tamponade after Russell viper bite. Case ReportA 26-year-old man developed breathlessness after being bitten by a Russell viper. The clinical and laboratory follow-up of this case confirmed the clinical diagnosis of toxin-induced disseminated intravascular coagulation. Interestingly, pericardial hemorrhage with large pericardial effusion was evident clinically as well as on electrocardiogram and echocardiogram, as an initial presentation without any other bleeding manifestations. The patient developed cardiac arrest and was revived with cardiopulmonary resuscitation. Emergency pericardiocentesis was carried out. He was given fresh frozen plasma in addition to snake antivenin along with symptomatic management. On the third day of hospitalization, the patient’s clinical and laboratory profile returned to normal and he was discharged on the fifth day. ConclusionPericardial hemorrhage may be due to toxin-induced myocardial damage or pericardial vessel injury coupled with coagulopathy, possibly in conjunction with vasculitis or endothelial damage. Practitioners and physicians should suspect and search for pericardial effusion in snake bite victims who develop breathlessness, and treat it vigorously in addition to antivenin therapy.

Antivenin-related Serum Sickness

Serum sickness is a type III hypersensitivity reaction that occurs due to the deposition of excessive circulating immune complexes in patients treated with foreign proteins or haptens. Serum sickness induced by antivenin for snakebites has been frequently reported in the USA, but not in Taiwan. This difference may be due to the efficacy and dosage of antivenins administered to treat snakebites in Taiwan. We report a case presenting with serum sickness after receiving a total of 20 vials of polyvalent antivenin therapy for the treatment of snakebite. A 59-year-old male suffered from fever, headaches, polyarthritis, and diffused skin rash approximately 10 days after administration of the antivenin. The large dose of antivenin administered in this case might have been the cause of the development of serum sickness. Physicians should be aware of the potential for serum sickness in cases of large-dose antivenin use.

Stenosing Flexor Tenosynovitis Following a Rattlesnake Bite

Snakebite victims have been described previously in orthopedic literature in regard to complications such as compartment syndrome and carpal tunnel syndrome. We introduce a previously unreported complication of stenosing flexor tenosynovitis in a patient bitten by a rattlesnake. After being bitten in her right forearm, the patient experienced mild systemic symptoms of fever and nausea and was assessed at an outside hospital, where it was determined that she did not suffer from envenomation and therefore did not require antivenin therapy. She presented to our institution 1 week later with signs and symptoms of acute, new-onset right thumb flexor tenosynovitis, with pain and tenderness at the level of the A1 pulley of the thumb, with intermittent triggering. She also presented the following week with ipsilateral carpal tunnel syndrome. The patient reported no such symptoms prior to the snakebite. Given the recent development of these conditions after her snakebite, in addition to her history of endocrine disorders, we believe that our patient suffered from envenomation that led to these complications. Nonoperative measures including splinting and steroid injections were taken, with mixed results, and surgical intervention was necessary. While the proper management of snakebites is controversial, especially in regard to the administration of antivenin, we believe our patient would have benefitted from immediate evaluation and consideration for antivenin.

Effect of antivenin dose on outcome from crotalid envenomation: 218 dogs (1988–2006)

To determine whether the dose of antivenin administered is associated with a difference in survival of crotalid-envenomated dogs. A secondary objective was to determine whether other covariables affect survival. Retrospective study (1988-2006). Private referral center and university small animal teaching hospital. Two hundred and eighteen dogs with evidence of crotalid envenomation and treatment with equine-derived antivenin. Administration of antivenin. Patient signalment, physical and clinicopathologic data at time of presentation, treatments, complications of antivenin therapy, length and cost of hospitalization, and outcome were recorded. Confidence intervals were determined for the difference in median number of vials administered and for median dosage for patients that lived versus died. Penalized logistic regression was performed to evaluate the effect of other covariables on survival. The median age of affected dogs was 3 years (range 6 w-12 y) with a median weight of 25.7 kg (range 1.95-86.4 kg). The median number of antivenin vials administered was 1.0 (range 1.0-10.0). Acute and chronic reactions were reported in 7% (16/218) and 0.9% (2/218) of dogs, respectively. Nine of 218 dogs (4.1%) died. The median number of vials administered to the nonsurvivors and survivors were 2.0 (range 1-5 vials) and 1.0 (range 1-10 vials), respectively. The median number of vials received was significantly different in dogs that died versus those that lived (P<0.05). Increased heart rate (P=0.02) and petechiation (P=0.04) were associated with decreased likelihood of survival, while diphenhydramine (P=0.02) and fluoroquinolone (P=0.046) administration was associated with increased likelihood of survival. The median duration of hospitalization was 1.0 day (range 2 h-22 d). The median cost of hospitalization was US$1592.00 (range US$267.20-US$6738.00). The administration of more vials of antivenin is potentially associated with negative outcome; however, a causal relationship has not been established. Controlled, prospective studies are needed to optimize antivenin administration.

Envenenamento por serpentes do gênero Bothrops no Estado da Bahia: aspectos epidemiológicos e clínicos

This study describes the clinical and epidemiological characteristics of 655 cases of Bothrops snakebites that were attended by and/or notified to the Bahia Antivenin Information Center, State of Bahia, Brazil, in 2001. The annual incidence in the State was 5.0 cases/100,000 inhabitants and lethality was 1%. The incidence was greatest in the North Coast microregion (21.9/100,000 inhabitants) and the municipality of Itanagra (92.9/100,000 inhabitants). The snakebites occurred predominantly during the day, affecting the lower limbs of men aged 11-30 years who worked in rural areas during the rainy period. Medical care was obtained more than 13 hours after the snakebite in 19% of the cases. Moderate (47.8%) and severe (23.6%) clinical presentations prevailed. The local and systemic clinical manifestations followed the usual pattern for Bothrops snakebites in Brazil. However, a few cases presented neurological manifestations, which are not usually attributed to Bothrops snakebites. The antivenin therapy used (7.7 blisters/patient) reflected the fact that the majority of the cases were moderate. Antivenins other than the univalent type were used in 2.3% of the cases.

A large single-center experience with treatment of patients with crotalid envenomations: outcomes with and evolution of antivenin therapy

Background Antivenin (crotalid) polyvalent (ACP; Antivenin Crotalidae Polyvalent; Wyeth, Melville, NY) is associated with frequent allergic reactions. Allergic reactions are fewer with ovine Fab antivenin (FabAV). This study describes the management of crotalid envenomations in patients treated with FabAV or ACP, and without antivenin. Methods We performed a retrospective chart review of crotalid envenomations over 10 years. Demographic data, hematologic profiles, details of antivenin administration, and in-hospital morbidity and mortality were collected. Results There were no mortalities and a single amputation. Fewer fasciotomies were performed in the FabAV (9%) group versus the ACP group (24%). Mean hospital stay was 3.4 days. No allergic reactions were associated with FabAV. Fourteen of 211 reactions were associated with ACP ( P < .001). Coagulopathy was frequent. Conclusions FabAV represents an improvement in management of crotalid envenomations because of reduced allergic reactions. Serious morbidity and mortality is rare. Coagulopathy is frequent but bleeding is not. Limb salvage is high. Surgical debridement and ACP are contraindicated when FabAV is available.

Study of Cardiac Changes in Egyptian Children with Scorpion Envenomation Before and After Antivenin Therapy

Study of Cardiac Changes in Egyptian Children with Scorpion Envenomation Before and After Antivenin Therapy

Loxosceles spider bites in the state of Paraná, Brazil: 1993-2000

This study presents the epidemiological analysis of 20,699 reported spider bites involving the Loxosceles genus in the state of Parana, Brazil, from 1993 to 2000. The incidence rate in the period was 290.24/100,000 inhabitants. The results show that 95.04% of the accidents occurred in two Health Regions of the state: greater metropolitan Curitiba (92.9%) and Irati (2.14%). The major incidence was recorded in greater metropolitan Curitiba (559.1/100,000). Loxosceles bites were more frequent in females (61%) than in males. Antivenin therapy was not necessary in 95.4% (19,662) of the cases. From the cases in which information about the time elapsed between the bite and medical treatment was recorded (9,679), 31.8% received treatment from 6 to 48 hours after the bite. Among the cases with severity rate recorded (12,096), 2.1% were severe, 50.4% moderate, and 47.4% mild. Seven deaths from Loxosceles bites were recorded, corresponding to a fatality rate of 0.03%.

Serum sickness in a dog associated with antivenin therapy for snake bite caused by Crotalus adamanteus

AbstractObjective: This case report describes antivenin‐associated acute and delayed hypersensitivity reactions in a dog envenomated by an Eastern diamondback rattlesnake (Crotalus adamanteus), specifically reviewing the syndrome of antivenin‐associated serum sickness. Clinician awareness of this syndrome is important in order to allow for its recognition and appropriate treatment.Case summary: A Boxer dog was envenomated by an Eastern diamondback rattlesnake. Shock, echinocytosis, and coagulopathy were manifested, and the dog was given antivenin crotalidae polyvalent therapy and supportive care. The early onset of an anaphylactoid reaction was attributed to antivenin therapy and was managed with diphenhydramine and subcutaneous epinephrine therapy. Fever, chemosis, and limb edema occurred during the 3rd through 6th hospital days following antivenin therapy and were consistent with serum sickness syndrome as described in humans. Further immunoassay support reflecting complement activation and response to treatment were characteristic.New information provided: To our knowledge, this describes the first reported case of antivenin‐associated serum sickness in a dog.

Snake, Spider, and Scorpion Envenomation in North America

Snake, Spider, and Scorpion Envenomation in North America

Snake, spider, and scorpion envenomation in North America.

1. G. Randall Bond, MD* 1. 2. *Associate Professor, Departments of Emergency Medicine and Pediatrics, Medical Director, Blue Ridge Poison Center, University of Virginia, Charlottesville, VA. After completing this article, readers should be able to: 1. Describe which measures for snakebite are harmful and should be avoided. 2. List the signs, symptoms, and findings that indicate a more significant envenomation and the need for intervention with antivenin. 3. Explain when a fasciotomy should be performed and when surgical consultation is necessary. 4. Describe the cornerstone of treatment for black widow spider envenomation. 5. Describe the treatment of brown recluse spider envenomation. In North America, approximately 2,500 children experience a poisonous snakebite each year. More than 95% of these are from pit vipers (family Crotalidae ), including rattlesnakes, moccasins, cotton mouths, and copperheads. Because children have smaller limbs and less subcutaneous tissue and they receive a larger dose of venom per kilogram, their clinical course often is more severe than that of adults. Fortunately, death is rare. ### SIGNS AND SYMPTOMS Pit vipers have no legs and no teeth for mastication. Their venom contains a variety of toxins to halt and kill their prey quickly and to begin the process of digestion from within. Specific components cause direct tissue injury, capillary leakage, coagulopathy, and neurotoxicity. Bites usually cause significant pain from the moment of envenomation. Swelling occurs at the site and progresses at a variable rate, depending on the amount and potency of the venom injected. Local areas may become extremely swollen and tense, and ecchymosis may be noted. Vascular compromise can occur, particularly of the digits. In time, fluid-filled or hemorrhagic bullae may form at the site of the bite, and eventually an area of necrosis may become apparent. Frequently, the first sign of systemic envenomation is tender regional lymph nodes. Other signs include nausea, a metallic taste in the mouth, muscle fasciculations, bleeding from intravenous puncture sites, and less commonly, hypotension and shock. Ptosis and weakness are common following envenomation by some subspecies of the …