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  5. Clinical entry: Naja sp., Asian cobras sp.

Clinic: Naja sp., Asian cobras sp.

Examine for venom effects

Local Effects


Bite site

  • Pain
  • Tender local (spreading) swelling
  • Blistering
  • Lymphangiopathy and lymphadenopathy
  • Necrotic skin

Eyes

  • Intense local pain
  • Blepharospasm
  • Palpebral oedema
  • Leucorrhoea
  • Photophobia
  • Clouding of vision
  • Temporary blindness

Neurological effects

  • Descending flaccid paralysis
    • Ptosis (not to be mixed up with tiredness / drowsiness; test: lid retraction with upward gaze).
    • Double vision (external ophthalmoplegia)
    • Difficulties to swallow (dysphagia) (bulbar paralysis) > inhalation of vomitus!
    • Difficulties to lift the head when lying on the back (‘broken neck syndrome’)
    • Cyanosis, shallow breathing, respiratory arrest (respiratory paralysis); respiratory arrest may be precipitated by obstruction of the upper airway by the paralysed tongue or inhaled vomitus. 
    • Weakness or loss of voluntary movement; movements of digits may still be possible, allowing the patient to communicate.
    • Loss of consciousness and generalized convulsions caused by hypoxaemia in patients who have respiratory paralysis.  

Species-specific envenoming pattern

The assessment of the envenoming pattern is based on the data from publication in which the identification of the snakes is clearly specified and in accordance with accepted criteria.

  

Local effects
(bite site1)

Local effects
(eyes4)

 Neurological
effects 
Naja atra6      
Naja naja      
Naja kaouthia2,5,7      
Naja mandalayensis      
Naja philippinensis3      
Naja samarensis      

Local effects

Bite site

1General with the exception of N. philippinensis

Pain, blistering surrounding a demarcated pale or blackened anaesthetic area of necrotic skin, regional lymphadenopathy. Putrid smell. Break down with extensive loss of skin and subcutaneous tissue. Skip lesions (necrotic skin separated by areas of apparently normal skin extending proximally up the limb) (Warrell 2023, WHO 2016).

2Naja kaouthia

Swelling: commences 2–3 h after the bite, at the latest 24–48 h after the bite (Reid 1964). The speed at which the swelling spreads and its extent are generally less than with Calloselasma rhodostoma bites.
If there is no local swelling within >1 h after the bite, it is almost certain that envenoming has not occurred (Reid 1964). All patients with systemic envenoming had local swelling at the site of the bite (Viravan et al. 1986).
Initially, the local swelling is a dirty colour around the area of the bite marks, which spreads from day to day. On the 3rd–4th day this grey-black area is surrounded by a red edge which sometimes has small blisters in it, while blood-filled blisters often form in the centre. After 4–5 days the swelling fluctuates, and after incision, the necrotic area becomes visible and reveals necrosis of a greater extent than is indicated by the superficial changes. The necrosis extends into the subcutaneous tissue. There is a danger that a local envenoming is initially regarded as harmless. Experience has shown, however, that necrosis occurs in almost all cases (Reid 1964). It is thus necessary to make sure the patient is observed for a sufficient length of time.
Nearly all patients who are injected with a significant amount of venom develop necrosis, even if local symptoms initially look only mild (Reid 1964). The time it took for necrosis to heal completely differed according to the extent of the necrosis and was on average 6 weeks (<10 cm2), 12 weeks (>10 cm2, <100 cm2) or 15 weeks (≥100 cm2). The administration of antivenom had no effect on the course of the necroses (Reid 1964).

3Naja philippinensis

mild

Eyes

4General

Venom ophthalmia from Asian species are considered less severe than that from African species. 
Intense local pain; Blepharospasm; Palpebral oedema; Leucorrhoea; photophobia, clouding of vision, temporary blindness
(Chu et al. 2010, Warrell 2023, WHO 2016).

5Naja kaouthia

Not a true spitting cobra, however spitting events have been reported from Bangladesh, Northeastern India and Nepal. Several cases of eye injuries due to spitting have, however, been reported (Rahman et al. 2025)

Neurological effects

6Naja atra

"It does not typically produce considerable neurotoxicity in humans” (Mao et al. 2024, Wong et al. 2010).

7Naja kaouthia

Ptosis, dysarthria, dysphagia, ophthalmoplegia, which commenced 3–4 h after drowsiness began, i.e. 4–9 h after the bite, occurred in all patients with systemic envenoming (by definition). Generalised weakness as a sign of paralysis of the skeletal musculature was last to occur (Reid 1964). Paralysis of the respiratory musculature with respiratory failure (Viravan et al. 1986). All patients with systemic envenoming displayed ptosis (Viravan et al. 1986).
Duration (mean): Ptosis 5 hrs (max 50 hrs), dysarthria 4.5 hrs (max 30 hrs); weak neck 5 hrs (max 45 hrs); difficulty swallowing 4 hrs (max 20 hrs); blurred vision 5 hrs (max 30 hrs); double vision 6 hrs (max 35 hrs); breathlessness 7 hrs (max 50 hrs); cyanosis 4 % (Faiz et al. 2017).
All patients exhibiting signs of advanced systemic neurotoxicity (e.g., bilateral complete ptosis, external ophthalmoplegia, dysphagia, dysphonia, weak grip strength, weak neck muscles, “broken neck” sign, or respiratory difficulty) had received Haffkine polyvalent antivenom (Faiz et al. 2017).
Severe neuromuscular weakness associated with envenoming was typically reversed, within 5–6 hours, by treatment with the only available antivenom (Indian Haffkine polyvalent antivenom).
Recurrent neurotoxicity in Naja kaouthia envenoming (Giri et al 2023).

Other effects

“Intractable hypotension can occur in patients envenomed by Asian cobras and king cobras, despite adequate respiratory support.” (Warrell 2023) 

Clinical management

See also (depending on the origin of the culprit)

Clinical Management: Indian Subcontinent and Southeast Asia

Clinical Management: Far East

for advice on post-First Aid measures, diagnosis (clinical, laboratory) and treatment (supportive, antivenom).

First Aid

Release of any type of tourniquet follow links above.

Naja philippinensis
'Tourniquets' delay the systemic uptake of cobra neurotoxins. This effect is maintained for a long period (in one case the neurological signs worsened after the tourniquet was removed after 30 h). When the tourniquet was removed abruptly, 11/34 study patients noticed a sudden intensification of their neurological symptoms within 10 min; 4/34 developed symptoms for the first time. Respiratory arrest occurred in 4/34 patients within 10 min; 1 of these patients had been asymptomatic until (Watt et al. 1988b - Prospective study: Tourniquet),

Local treatment

Bite site

Pain control
Tetanus prophylaxis
Standard wound care
Necroses: debridement; split-thickness skin grafting
Systemic antibiotics: standard indications
WHO (2010, 2016) 

Eyes

“
1) urgent decontamination by copious irrigation

2) analgesia by vasoconstrictors with weak mydriatic activity (e.g. epinephrine) and limited topical administration of local anaesthetics (e.g. tetracaine)

3) exclusion of corneal abrasions by fluorescein staining with a slit lamp examination and application of prophylactic topical antibiotics

4) prevention of posterior synechiae, ciliary spasm and discomfort with topical cycloplegics and 5) antihistamines in case of allergic kerato-conjunctivitis.

Topical or intravenous antivenom and topical corticosteroids are contraindicated.

” Chu et al. (2010)

Tetanus prophylaxis

Systemic supportive treatment

A general understanding of emergency medicine is required, or can be found in emergency medicine guidelines, e.g. ABCDE approach, WHO-ICRC Basic Emergency Care.

Follow SAMPLE & ABCDE ApproAch

Obey asian cobras - specific features

see 

  • 'Species-specific envenoming pattern' above

and

Key issues

Respiratory failure

Lifesaving in neurotoxic Asian cobra envenoming (as supportive treatment and when antivenoms are not available or fail):

Airway management
Breathing: Oxygen ⇨ assisted ventilation ⇨ mechanical ventilation

Naja philippinensis
Endotracheal intubation and artificial respiration are the most important measures in the case of respiratory insufficiency. The paralytic effect of cobra venom is reversible with time (Watt et al. 1989).

Anticholinesterase drugs to improve neuromuscular transmission

N. kaouthia

“Edrophonium significantly improved the ability of patients to open the eyes, endurance of upward gaze, and peak expiratory flow rate suggesting that a longer-acting anticholinesterase drug (neostigmine) could be recommended for first aid.” (Faiz et al. 2017).

Neurotoxic effects are completely reversible, either in response to antivenom or spontaneously within 1-4 days of mechanical ventilation, ocular muscles within 2–4 days and full recovery of motor function within 3–7 days. (Warrell 2023, WHO 2016).

Naja philippinensis
Edrophonium (Tensilon®) and long-acting anticholinesterase inhibitors (e.g. neostigmine methylsulphate)
By means of the Tensilon® test, the efficacy of neostigmine can be reliably predicted (Watt et al. 1986).
Administration of edrophonium (Tensilon®) 2 h after the patient received antivenom was significantly more effective than antivenom and either completely reversed signs of paralysis or at least caused a significant improvement (Watt et al. 1989 Clinical trial: Edrophonium vs antivenom).
Neurological signs and symptoms could be controlled with a dose of neostigmine adjusted for the individual patient. There was improvement of expiratory and inspiratory pressure, forced vital capacity and the ability to cough, speak and swallow, as well as improvement of ptosis and upward gaze. Before administration of treatment and under placebo treatment, EMG findings corresponded to those for myasthenia gravis and normalised with edrophonium. No serious side effects of edrophonium or neostigmine were observed in any patient. Abdominal pain was recorded most frequently, but this was manageable with atropine (Watt et al. 1986 - Clinical trial: Edrophonium).

Specific treatment (antivenoms)

References 

  • Chu ER, Weinstein SA, White J, Warrell DA.Venom ophthalmia caused by venoms of spitting elapid and other snakes: Report of ten cases with review of epidemiology, clinical features, pathophysiology and management. Toxicon. 2010 Sep 1;56(3):259-72. Epub 2010 Mar 21. PMID: 20331993. doi.org/10.1016/j.toxicon.2010.02.023
  • Warrell DA. Venomous and poisonous animals. In: Farrar J, Garcia PJ, Hotez T, Junghanss T, Kang G, Laloo D (eds.). Manson’s tropical diseases. 24th ed. Elsevier; 2023.
  • Warrell DA, Williams DJ. Clinical aspects of snakebite envenoming and its treatment in low-resource settings. Lancet. 2023 Apr 22;401(10385):1382-1398. PMID: 36931290. https://doi.org/10.1016/s0140-6736(23)00002-8
  • WHO-ICRC Basic Emergency Care: approach to the acutely ill and injured https://www.who.int/publications-detail-redirect/basic-emergency-care-approach-to-the-acutely-ill-and-injured  https://cdn.who.int/media/docs/default-source/integrated-health-services-(ihs)/csy/bec-quick-cards/becp-edu29-pdf-en-finl.pdf?sfvrsn=2532d61b_2 
  • WHO ABCDE Approach https://cdn.who.int/media/docs/default-source/integrated-health-services-(ihs)/csy/bec-quick-cards/becp-edu29-pdf-en-finl.pdf?sfvrsn=2532d61b_2
  • WHO (2010) Wound and lymphoedema management. WHO/HTM/NTD/GBUI/20101 I. 2010. https://www.who.int/publications/i/item/9789241599139
  • WHO (2016) Guidelines for the management of snakebites. 2nd edition. https://www.who.int/publications/i/item/9789290225300
  • WHO Snakebite Information and Data Platform https://www.who.int/teams/control-of-neglected-tropical-diseases/snakebite-envenoming/snakebite-information-and-data-platform

Species-specific evidence

Naja atra

Taiwan

  • Mao et al. (2024)
    Review

Hong Kong

  • Wong et al. (2010)
    15 bites: identification: “The species of snake was confirmed by examination of the specimen (dead or alive), opinion sought from local experts, identification by the patient with the snake photo handbook, or the combination of typical clinical features and patients’ descriptions of the appearance of the snakes.”

    Signs & symptoms
    Local effects
    Severe local symptoms. Pain, swelling, and tissue necrosis (Mao et a. 2024).
    4/15 swelling, 6/14 necrosis (Wong et al. 2010).
    Neurological effects
    ”It does not typically produce considerable neurotoxicity in humans” (Mao et al. 2024).
    0/15 neurological effects (Wong et al. 2010).

Naja kaouthia

Bangladesh

  • Faiz et al. (2017)
    70 cases; identification: “The identity of the biting snake was established in every case, either by examining the dead snake or by the retrospective detection of venom antigens of N. kaouthia in the patient’s serum using ELISA. The only other species of cobra known to be present elsewhere in Bangladesh is the spectacled cobra, N. naja. The venom of this species could theoretically cross-react in the ELISA test. However, no specimen of N. naja could be located in any natural history or other zoological unit in southeast Bangladesh and no specimens had been obtained from the catchment area of CMCH during decades of clinical and field research. It is not recognized by local expert zoologists, or snake collectors as being a part of the local fauna.”
  • Rahman et al. (2025)

India (Assam)

  • Giri et al (2023)
    1 case; identification: morphological.

Northwest Malaysia

  • Reid (1964)
    47 N. naja ssp. bites; identification: morphological by Reid: N. n. leucodira (= N. kaouthia) 45/47, N. n. kaouthia 2/47 (Viravan et al. (1986): "Reid's 47 patients were bitten by cobras morphologically similar to N. n. kaouthia, but mistakenly described as N. n. leucodira").

Thailand

  • Viravan et al. (1986)
    24 Naja n. kaouthia bites (N. kaouthia or N. siamensis); identification: ELISA detection of N. n. kaouthia venom antigen in serum 22/24; positive ELISA detection and morphological identification of the dead snake 11/22, only positive ELISA identification 11/22; only morphological identification of the dead snake 2/24.

Captive (“pet”) snakes

  • Gold (1996)
    1 case; identification: morphological.

    Signs & symptoms
    Local effects
    Bite site
    Swelling: commences 2–3 h after the bite, at the latest 24–48 h after the bite (Reid 1964). The speed at which the swelling spreads and its extent are generally less than with Calloselasma rhodostoma bites.
    If there is no local swelling within >1 h after the bite, it is almost certain that envenoming has not occurred (Reid 1964). All patients with systemic envenoming had local swelling at the site of the bite (Viravan et al. 1986).
    Initially, the local swelling is a dirty colour around the area of the bite marks, which spreads from day to day. On the 3rd–4th day this grey-black area is surrounded by a red edge which sometimes has small blisters in it, while blood-filled blisters often form in the centre. After 4–5 days the swelling fluctuates, and after incision, the necrotic area becomes visible and reveals necrosis of a greater extent than is indicated by the superficial changes. The necrosis extends into the subcutaneous tissue. There is a danger that a local envenoming is initially regarded as harmless. Experience has shown, however, that necrosis occurs in almost all cases (Reid 1964). It is thus necessary to make sure the patient is observed for a sufficient length of time.
    Frequency of swelling and necrosis as local signs of envenoming in the populations studied (see above: studies of Reid 1964, Viravan et al. 1986).
    Nearly all patients who are injected with a significant amount of venom develop necrosis, even if local symptoms initially look only mild (Reid 1964).
    The time it took for necrosis to heal completely differed according to the extent of the necrosis and was on average 6 weeks (<10 cm2), 12 weeks (>10 cm2, <100 cm2) or 15 weeks (≥100 cm2). The administration of antivenom had no effect on the course of the necroses (Reid 1964).
    Most of the 70 patients, swelling and pain of the bitten limb. Blistering and necrosis in 19/70 patients (Faiz et al. 2017).
    Eyes
    Naja kaouthia is not a true spitting cobra. Several cases of eye injuries due to spitting have, however, been reported (Rahman et al. 2025).
    Neurological effects
    Ptosis, dysarthria, dysphagia, ophthalmoplegia, which commenced 3–4 h after drowsiness began (see below), i.e. 4–9 h after the bite, occurred in all patients with systemic envenoming (by definition). Generalised weakness as a sign of paralysis of the skeletal musculature was last to occur (Reid 1964). Paralysis of the respiratory musculature with respiratory failure (Viravan et al. 1986).
    All patients with systemic envenoming displayed ptosis (Viravan et al. 1986).
    58/70 experienced severe neurotoxicity. Ptosis 83%; duration mean 5 hrs (max 50 hrs), dysarthria 75%; mean 4.5 hrs (max 30 hrs); weak neck 64%, mean 5 hrs (max 45 hrs); difficulty swallowing 59%, mean 4 hrs (max 20 hrs); blurred vision 42%. mean 5 hrs (max 30 hrs); double vision 30%, mean 6 hrs (max 35 hrs); breathlessness 30%, mean 7 hrs (max 50 hrs); cyanosis 4 % (Faiz et al. 2017).
    All patients exhibiting signs of advanced systemic neurotoxicity (e.g., bilateral complete ptosis, external ophthalmoplegia, dysphagia, dysphonia, weak grip strength, weak neck muscles, “broken neck” sign, or respiratory difficulty) had received Haffkine polyvalent antivenom (Faiz et al. 2017).
    Severe neuromuscular weakness associated with envenoming was typically reversed, within 5–6 hours, by treatment with the only available antivenom (Indian Haffkine polyvalent antivenom).
    Recurrent neurotoxicity in Naja kaouthia envenoming (Giri et al. 2023).
    Other signs & symptoms
    Drowsiness occurred in all patients with systemic envenoming, beginning 1–5 h after the bite, and was the earliest sign of systemic envenoming (6/6) (Reid 1964

    Clinical management
    Systemic (selected problems)
    Neostigmine methylsulphate (Gold 1996)
    “Edrophonium significantly improved the ability of patients to open the eyes, endurance of upward gaze, and peak expiratory flow rate suggesting that a longer-acting anticholinesterase drug (neostigmine) could be recommended for first aid.” (Faiz et al. 2017).
    Antivenom
    “Severe neuromuscular weakness associated with envenoming was typically reversed, within 5–6 hours, by treatment with the only available antivenom (Indian Haffkine polyvalent antivenom)”. Most patients experienced moderate-to-severe adverse reactions (Faiz et al. 2017).
    “Antivenom did not influence local blistering and necrosis appearing in 19 patients” (Faiz et al. 2017).

Naja mandalayensis

Myanmar

  • Sai-Sein-Lin-Oo et al. (2020)
    13 cases bitten; 2 cases were spat at. Identification: Snakes brought in by patients who had been bitten or spat.

    Signs & symptoms
    Local effects
    Bite site
    8/13 swelling, 2/13 bleeding from the bite wounds, 2/13 blistering, 2/13 local lymphadenopathy, 4/13 local necrosis (Sai-Sein-Lin-Oo et al. 2020).
    Eyes
    Redness, lacrimation, periocular swelling, burning sensation in the affected eyes(Sai-Sein-Lin-Oo et al. 2020).
    Neurological effects
    5 / 15 patients had one or more of the following signs / symptoms: Bilateral ptosis, blurred vision (a subjective symptom possibly attributable to paralysis of visual accommodation or external ophthalmoplegia), slurred speech, inability fully to open the mouth, difficulty in swallowing, respiratory distress, and drowsiness (Sai-Sein-Lin-Oo et al. 2020).

Naja naja

Sri Lanka

  • Ariaratnam et al. (2009)
    45 cases; identification: Patients were selected for the study if they had a history of snake bite and had brought with them to hospital the snake responsible.
  • Theakston et al. (1990)
    2 cases; identification: Specific venom antigen.

    Signs & symptoms
    Local effects
    Bite site
    2/2 signs of local envenoming, both severe.  The patient with neurotoxic envenoming: “Swelling in the bitten limb reached the inguinal ligament- and blistering over an area 15 x 10 cm appeared at the ankle on the third day after the bite. By the sixth day there was a demarcated darkened area with a putrid smell which required surgical debridement.” (Theakston et al. 1990).
    41/45 (Local swelling developed in 91%, blistering in 84%, and necrosis in 67%) (Ariaratnam et al. 2009).
    Neurological effects
    1/2 respiratory paralysis (Theakston et al. 1990).
    36/45 neurological signs: 35 had ptosis, 29 had ophthalmoplegia, 6 had dysphagia, and 3/45 had respiratory failure that required mechanical ventilation (Ariaratnam et al. 2009).

Naja philippinensis

Philippines

  • Watt et al. (1986) - Clinical trial: Edrophonium
    20 patients
  • Watt et al. (1989) Clinical trial: Edrophonium vs antivenom
    8 patients
  • Watt et al. (1988b) - Prospective study: Tourniquet
    Watt et al. (1988a) - Case series
    39 cases. Identification: specific antigen with ELISA 24/34 (34/39 were tested); exclusively morphological identification 4/39; by patients or relatives 4/39 and 7/39; with the exclusion criterion that there are no other medically significant neurotoxic snakes in the Philippines and the patients showed neurotoxic signs and symptoms.
  • Watt et al. (1987a) - Case report

    Signs & symptoms
    Local effects
    No local swelling 14/39; Also, bite marks may be undetectable (Watt et al. 1987a).
    Minor local swelling 21/39; 1 patient developed superficial necrosis.
    Extensive local swelling 4/39; 2 patients developed superficial necrosis (Watt et al. 1988a).
    3/39 patients developed local, superficial necrosis; in 1 patient a finger was amputated (Watt et al. 1988a). However, overall, only minor local morbidity after Philippine cobra bites, e.g. compared to those of Malaysian cobras.
    Neurological effects
    Signs of paralysis 38/39; initial neurotoxic sign: ptosis 33/39, slurred speech 3/39, dysphagia 1/39, respiratory dysfunction 1/39. Varying degrees of respiratory paralysis, which was always associated with ptosis and glossopharyngeal paralysis 18/39.
    Over a third of patients with neurotoxic signs and symptoms had no local swelling; this was the case even though sometimes drastic first aid measures had been used, and a tourniquet was normally applied. The time interval between the bite and the first neurotoxic sign or symptom was 1 h (0.05–24 h), ptosis 1 h (0.05–24 h), glossopharyngeal paralysis 1.8 h (0.08-30 h) and respiratory paralysis 1.3 h (0.17–2 h).
    Cardiac effects
    Arrhythmias and arterial hypotension in several patients with respiratory paralysis: secondary causes (hypoxia) likely (Watt et al. 1988a).
    Other signs & symptoms
    Vomiting 12/39.
    Drowsiness 4/39. Can be difficult to distinguish from ptosis and requires careful questioning of the patient; possibly a reason for the low incidence of this symptom compared to other Asian cobra bites (Watt et al. 1988a).

    Laboratory and physical investigations (selected problems)
    ECG
    Performed in 13/39 patients and was conspicuous in only 3 patients. 2 had ST segment elevations, 1 had sinus bradycardia. In all 3 patients the ECG changes persisted during observation in hospital and on follow-up examinations (no convincing indications of primary cardiac effects of the venom) (Watt et al. 1988a).

    First aid
  • Watt et al. (1988b)  - Prospective study: Tourniquet
    36 patients who had been bitten by Naja philippinensis, had had a 'tourniquet' applied and who developed neurotoxic signs and symptoms. Identification: specific antigen with ELISA 24/36 (additional morphological identification in 2 of these patients); with the aid of photos and the snake's behaviour (spread hood) 4/36; only morphological 2/36; with the exclusionary diagnosis that there are no other medically important neurotoxic snakes in the Philippines 6/36. Definition of a 'tourniquet': any type of wide band or ligature located proximal to the site of the bite.
    Findings:'Tourniquets' delay the systemic uptake of cobra neurotoxins. This effect is maintained for a long period (in one case the neurological signs worsened after the tourniquet was removed after 30 h)
    When the tourniquet was removed abruptly, 11/34 noticed a sudden intensification of their neurological symptoms within 10 min; 4/34 developed symptoms for the first time. Respiratory arrest occurred in 4/34 patients within 10 min; 1 of these patients had been asymptomatic until.

    Clinical management
    Systemic (selected problems)
    Endotracheal intubation and artificial respiration are the most important measures in the case of respiratory insufficiency.
    The paralytic effect of cobra venom is reversible with time (Watt et al. 1989).
    Edrophonium (Tensilon®) and long-acting anticholinesterase inhibitors (e.g. neostigmine methylsulphate)
    By means of the Tensilon® test, the efficacy of neostigmine can be reliably predicted (Watt et al. 1986). Administration of edrophonium (Tensilon®) 2 h after the patient received antivenom was significantly more effective than antivenom and either completely reversed signs of paralysis or at least caused a significant improvement (Watt et al. 1989).
    Neurological signs and symptoms could be controlled with a dose of neostigmine adjusted for the individual patient. There was improvement of expiratory and inspiratory pressure, forced vital capacity and the ability to cough, speak and swallow, as well as improvement of ptosis and upward gaze. Before administration of treatment and under placebo treatment, EMG findings corresponded to those for myasthenia gravis and normalised with edrophonium. No serious side effects of edrophonium or neostigmine were observed in any patient. Abdominal pain was recorded most frequently, but this was manageable with atropine (Watt et al. 1986).

Naja samarensis

Philippines

  • Aoki et al. (2025)
    4 cases confirmed by photographs of the offending snakes (2 dry bites); 44 cases classified as probable cases (10 dry bites; 1 spit in the eyes) (“a case was considered probable for this species if any of the following criteria were met: black and yellow snake; black snake accompanied by any signs of envenomation; predominantly neurotoxic envenomation, with no evidence supporting an alternative diagnosis. Due to differences in geographical distribution, N. philippinensis and N. sumatrana were not considered to be probable snakes involved. A black and/or olive brown snake with envenomation might be from a king cobra, but we did not consider this due to its rarity”)
    Weakness of the study: mostly probable cases.
  • Paghubasan et al. (2023)
    5 cases (4 bites, 1 spat in eyes); identification: confirmed in photos by an expert local herpetologist.

    Signs & symptoms
    Local effects
    Bite site
    31/48 cytotoxic signs (1/31 was among the four photographically confirmed cases) (Aoki et al. 2025)
    Pain 4/4, swelling 4/4, necrosis 2/4 (Paghubasan et al. 2023).
    Eyes
    One was spit in the eyes and had eye pain (Aoki et al. 2025).
    1/1 pain, redness of eye (Paghubasan et al. 2023).
    Neurological effects
    23/48 neurological signs.19/48 cytotoxic and neurological signs (1/19 was among the four photographically confirmed cases). 10/19 respiratory failure (Aoki et al. 2025).
    Ptosis 4/5, paralysis 2/5 of which 1/2 respiratory failure (Paghubasan et al. 2023).

References

  • Aoki Y, Paghubasan J, Tiglao PJ, Sarmiento MJ, Arrieta R, Tan MA, Sarsalijo MS, Aquino GJB, Beronilla-Uraga MG, Comandante JDL, Santamaria EB, Malijan GMB, Suzuki S, Takahashi K, Yamano S, Smith C, Hayakawa K, Tasaki O, Agosto LC, Warrell DA, Ariyoshi K. Characteristics of snakebite patients due to Naja samarensis in the Philippines: a prospective hospital-based study. Trans R Soc Trop Med Hyg. 2025 Jan 3. PMID: 39749526. https://doi.org/10.1093/trstmh/trae110
  • Ariaratnam CA, Sheriff MH, Arambepola C, Theakston RD, Warrell DA. Syndromic approach to treatment of snake bite in Sri Lanka based on results of a prospective national hospital-based survey of patients envenomed by identified snakes. Am J Trop Med Hyg. 2009 Oct;81(4):725-31. PMID: 19815895. https://doi.org/10.4269/ajtmh.2009.09-0225
  • Faiz MA, Ahsan MF, Ghose A, Rahman MR, Amin R, Hossain M, Tareq MNU, Jalil MA, Kuch U, Theakston RDG, Warrell DA, Harris JB. Bites by the Monocled Cobra, Naja kaouthia, in Chittagong Division, Bangladesh: Epidemiology, Clinical Features of Envenoming and Management of 70 Identified Cases. Am J Trop Med Hyg. 2017 Apr;96(4):876-884. Epub 2017 Jan 30. PMID: 28138054; PMCID: PMC5392636. https://doi.org/10.4269/ajtmh.16-0842
  • Giri S, Taye SJ, Shyam R, Saikia B, Jangid R, Yasmin R, Doley R. Recurrent neurotoxity in Naja kaouthia envenomation: A case report from Assam, India. Toxicon. 2023 Jan 15;222:106990. PMID: 36470487. https://doi.org/10.1016/j.toxicon.2022.106990
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