Description
Scorpion Venom Antiserum is of equine origin derived from the plasma of the horses, ponies, mules etc., that have been hyperimmunised against the venom of Red Scorpion (Buthus tamulus). Serum obtained from plasma contains purified, enzyme refined and concentrated specific heterologous immunoglobulins. It is used as a passive immunising agent and affords protection to the susceptible victims against the sting of Red Scorpion.

1ml of the reconstituted 'Scorpion Venom Antiserum' neutralizes 1.0 mg of dried Red Scorpion venom. It also contains not more than 0.25% w/v phenol l. P. as preservative. The moisture content in the Lyophilised 'Scorpion Venom Antiserum' does not exceed 1 Per cent.

Indications
The Scorpion Venom Antiserum is indicated for all stings caused by Red Scorpion venom where patient presents with clinical signs and symptoms of envenomation.

Precautions
Following precautions are to be observed before administration of scorpion venom antiserum.

1. Elicit history of familial allergic disorders such as asthma, eczema, and drug allergy from the patient.
2. Whether he had received earlier, injection of serum such as antitetanus serum, Antidiphtheria serum etc.
3. Carry out the sensitivity test on the patient. Inject subcutaneously 0.1ml of the serum-diluted 1:10. Observe the patient for 30 minutes for local or general reactions, if any. In the absence of adverse reactions, administer the requisite dose by the chosen route of injection.
4. Keep handy Adrenaline Injection (Epinephrine) 1 ml 1:1000 along with antihistamines and steroids to meet any emergency arising out of sensitivity reactions.
5. After administering the full dose of serum, the patient should be kept under observation for at least 30 minutes.
6. If a patient is found sensitive to the equine antiserum, you may desensitise him by administering graded doses of the antiserum at regular and adequate intervals. Before desensitising the patient, the doctor has to decide whether serotherapy is really needed.
7. In case of sensitive individuals where time factor is of paramount importance, it is advisable to administer Scorpion Venom Antiserum under the cover of Adrenaline INJ. (Epinephrine) 1ml (1:1000) I.M. and antihistamines without awaiting results of the test dose.

Contraindications
There are no known contraindications for the administration of Scorpion Venom Antiserum.

Adverse Drug Reactions
The serum being heterologous is liable to cause sensitivity reactions in occasional patient. The immediate reaction is anaphylactic shock (immediate hypersensitivity) characterized by sweating, pallor, bronchospasm, laryngospasm, hypotension leading to shock, coma and death.

Treatment consists of prompt administration of Epinephrine Injection, steroids and antihistamines along with ancillary measures such as endotracheal intubation, oxygen therapy and treatment of shock.

A late serum sickness like syndrome (delayed hypersensitivity) occurring seven to eight days after serum administration consists of fever, rashes, Iymphadenopathy, arthralgias. This is usually self-limiting and does not require treatment. If the precautions mentioned above are followed, there is less likelihood of any of these reactions occurring.

Grading of Envenomation
Envenomation following a scorpion sting is graded as follows:

Grade I: Signs of peripheral failure with cold and clammy, extremities, sweating, restlessness and hypotension.
Grade II: Signs with sudden onset of tachycardia, gallop rhythm, nausea and vomiting (suggestive of myocarditis).
Grade III: Neurotoxin Manifestations. The Scorpion Venom, Antiserum should be administered at the earliest.

Administration
Prior to administering the Scorpion Venom Antiserum it is obligatory to observe precautions and carry out sensitivity test as mentioned at B-3. The usual mode of administration of Scorpion Venom Antiserum is either by intramuscular or intravenous route.

Generally, 10ml of the reconstituted Scorpion Venom Antiserum is sufficient for the treatment. However, if the patient continues to show clinical signs of envenomation for more than 3 hours or if the signs aggravate further, 10ml of the antiserum may be administered by intravenous route. In very rare cases, further 10ml will have to be given.

Storage
Being Lyophilised the Scorpion Venom Antiserum is stable at room temperature and does not require special storage facilities. Ideally, it should be stored in a cool dark place, away from excessive heat.

Presentation
10 ml. vial x box of 1. One FFS container of Sterile Water for Injection IP 10ml accompanies each vial of Scorpion Venom Antiserum for the purpose of reconstitution of Lyophilised Scorpion Venom Antiserum.

Some Important Dont's

1. Ligature and cryotherapy
2. Cutting, incision and suction
3. Use of respiratory depressants, diuretics, digitalis, atropine, corticosteroids and antihistamines
4. Use of Snake Antivenin
5. Mixing of Adrenaline (Epinephrine) with Lignocaine (for local anaesthesia) to relieve pain at the site of sting
   

Emetine Hydrochloride, being protoplasmic poison, its toxic effect on the myocardium may cause hypotension, tachycardia, precordial pain, dyspnea and ECG abnormalities. HENCE IT SHOULD NEVER BE ADMINISTERED LOCALLY AT THE SITE OF STING TO RELIEVE PAIN.

Associated Theraphy
Insulin-glucose therapy is advised. 0.3 units of regular Insulin/g of glucose and glucose at the rate of 0.1 g/ kg/hr. This glucose insulin is to be given as continuous infusion. Dopamine or dobutamine drip in 5% glucose (5 to 7 mcg/kg/minute) may also be simultaneously given to maintain the blood pressure. If the patient presents with hypertension during the initial phase of transient hypertension, give sublingual Nifedipine 5 mg in children and 10mg in adults.