Snake Venom Antiserum

Indications

Pain Nausea and Vomiting

Antivenom is indicated for bites caused by Cobra, Common Krait, Russell's Viper and Saw-Scaled Viper, where the patient presents with one or more of the following visible clinical signs and symptoms of envenomation. Local envenomation: presence of bite marks with or without oozing of blood, blistering and change in color of skin. Rapidly progressive or massive swelling involving more than half of the bitten limb within a few hours of the bite, without a tourniquet. Development of enlarged, tender lymph nodes draining the bitten part within a couple of hours after the bite. Systemic envenomation: neurotoxic syndrome, meaning signs of neuro-paralysis such as blurring of vision, double vision, and difficulty in swallowing, a sleepy feeling, drooping of the head, slurring of speech with the voice becoming indistinct, shallow breathing, ptosis, ataxia, respiratory paralysis and generalized flaccid paralysis. Hemotoxic syndrome, meaning spontaneous systemic bleeding, nausea, vomiting, abdominal pain and abdominal tenderness suggestive of gastro-intestinal or retro-peritoneal bleeding and/or renal damage, coagulopathy detected by 20 minute WBCT with or without external bleeding, and shock. Immediate actions and first aid: quick and positive measures should be taken to meet the emergency. Do not try to catch or kill the snake without proper tools, and avoid unnecessary exposure to it. The patient should be moved to a well-ventilated and quiet place and have his or her movement restricted. The patient should be reassured to help overcome fear. Immobilize the bitten part by applying an immobilization bandage as would be done for a fracture, and keep the bitten part below heart level. Ligation with a tourniquet should be avoided; however, if one is applied, it should be tied at a moderate distance above the bitten part to prevent the venom from entering the circulation. The patient should be taken immediately to the nearest medical centre for treatment without loss of time.

⚠️ Always consult a registered physician before taking any medicine.

Pharmacology

Snake venom antiserum is a sterile preparation of antitoxin globulins and their derivatives. It remains the only specific treatment available for venomous snake bites.

Pregnancy & Breastfeeding

Given the risk posed by a snake bite, pregnancy does not rule out the use of Snake Venom Antiserum after a bite has occurred.

⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.

Dosage Reference

⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.

Adults: Snake venom antiserum remains, at present, the only specific antidote for snake envenomation, and giving an adequate dose promptly is of paramount importance for neutralizing unbound circulating venom components and achieving an early response to treatment. Any delay in administration may increase the dose required and reduce its effectiveness. Because clinical signs can vary due to many factors such as the type and size of the snake, the time of reporting after the bite, the amount of venom injected, and seasonal and regional variation in venom composition, no precise dosage can be recommended. However, taking into account the average quantity of venom injected at the time of a bite and the degree of envenomation, it is recommended that an initial dose of 5 to 10 vials of Snake venom antiserum be given by slow intravenous infusion, either undiluted at a speed of not more than 2 ml per minute or diluted with normal or glucose saline at a rate of 5 to 10 ml per kg body weight over one hour. Children should receive the same dose as adults. Constant monitoring of vital signs at frequent intervals during the first hour is recommended. Whether further dosing is needed depends on the extent of reversal of coagulopathy, confirmed after 6 hours of antiserum administration by WBCT in haemotoxic bites, or on whether symptoms persist or worsen, or respiratory failure continues, in neurotoxic bites after 1 hour of antiserum administration. If the blood remains incoagulable or there are no signs of reversal of paralysis, a further dose of 5 to 10 vials of antiserum should be given, by the slow intravenous route only. Administration by the intramuscular route or locally around the bite wound is not recommended. In most cases of both neurotoxic and haemotoxic bites, a total dose of 15 to 20 vials is adequate, unless a proven recurrence of envenomation is established, in which case further doses can be given according to the patient's clinical condition. The hypersensitivity skin test has no predictive value and should therefore not be used.