Antivenin (Lactrodectus mactans), Equine Origin - black widow spider antivenin
Status: approved; marketed
Organizations involved:
Merck & Co., Inc. – Manuf.; R&D; Tech.; World mark
Cross ref: See the Antivenin Products entry (#906).
Description: Antivenin (Lactrodectus mactans), Equine Origin is a lyophilized (freeze-dried) formulation of immune globulin (containing antibodies) fractionated from the blood of healthy horses immunized with venom of black widow spiders (Lactrodectus mactans). The product is standardized by biological assay in mice, with one dose of Antivenin neutralizing not less than 6,000 mouse LD50 of Lactrodectus mactans venom. One unit of Antivenin will neutralize one average mouse lethal dose of black widow spider venom when the Antivenin and the venom are injected simultaneously in mice under suitable conditions.
The product is packaged in vials along with a 2.5 mL vial of Sterile Diluent for Antivenin for reconstitution and intravenous injection. Thimerosal (mercury derivative) at a concentration of 1:10,000 (0.1 mg mercury/mL) is added to the product as an antimicrobial preservative (see entry #939). Each vial contains not less than 6,000 Antivenin units. When constituted, the product contains not more than 20.0% solids. Antivenin is stored and shipped at 2-8°C (36-46°F; refrigerated).
Nomenclature: Antivenin (Lactrodectus mactans) [TR FDA]; Black Widow Spider Antivenin, Equine Origin [SY]; NDC 0006-4084-00 [NDC]
Companies.: Antivenin (Lactrodectus mactans), Equine Origin was developed and is manufactured by Merck & Co., Inc. CBER/FDA est. no. 0002. It is marketed by Merck in the U.S. and internationally.
FDA class: Biologic PLA
CBER class: Antitoxins, Antivenins, Enzymes and Venoms
Approvals: Date = 19360213; first approval
Indications: [portion of the "INDICATIONS AND USAGE” section from product insert/labeling]:
Antivenin (Latrodectus mactans), is used to treat patients with symptoms due to bites by the black widow spider (Latrodectus mactans). Early use of the Antivenin is emphasized for prompt relief.
Local muscular cramps begin from 15 minutes to several hours after the bite which usually produces a sharp pain similar to that caused by puncture with a needle. The exact sequence of symptoms depends somewhat on the location of the bite. The venom acts on the myoneural junctions or on the nerve endings, causing an ascending motor paralysis or destruction of the peripheral nerve endings. The groups of muscles most frequently affected at first are those of the thigh, shoulder, and back. After a varying length of time, the pain becomes more severe, spreading to the abdomen, and weakness and tremor usually develop. The abdominal muscles assume a boardlike rigidity, but tenderness is slight. Respiration is thoracic. The patient is restless and anxious. Feeble pulse, cold, clammy skin, labored breathing and speech, light stupor, and delirium may occur. Convulsions also may occur, particularly in small children. The temperature may be normal or slightly elevated. Urinary retention, shock, cyanosis, nausea and vomiting, insomnia, and cold sweats also have been reported. The syndrome following the bite of the black widow spider may be confused easily with any medical or surgical condition with acute abdominal symptoms.
The symptoms of black widow spider bite increase in severity for several hours, perhaps a day, and then very slowly become less severe, gradually passing off in the course of two or three days except in fatal cases. Residual symptoms such as general weakness, tingling, nervousness, and transient muscle spasm may persist for weeks or months after recovery from the acute stage.
If possible, the patient should be hospitalized. Other additional measures giving greatest relief are prolonged warm baths and intravenous injection of 10 mL of 10 percent solution of calcium gluconate repeated as necessary to control muscle pain. Morphine also may be required to control pain. Barbiturates may be used for extreme restlessness. However, as the venom is a neurotoxin, it can cause respiratory paralysis. This must be borne in mind when considering use of morphine or a barbiturate. Adrenocorticosteroids have been used with varying degrees of success. Supportive therapy is indicated by the condition of the patient. Local treatment of the site of the bite is of no value. Nothing is gained by applying a tourniquet or by attempting to remove venom from the site of the bite by incision and suction.
In otherwise healthy individuals between the ages of 16 and 60, the use of Antivenin may be deferred and treatment with muscle relaxants may be considered
Status: This product is, presumably, also approved (under equivalents of IND, named patient use, compassionate IND, etc.) in European and other countries worldwide.
Medical: After a Black Widow spider bite, the venom (toxin) acts on the myoneural junctions or the nerve endings, causing an ascending motor paralysis or destruction of the peripheral nerve endings. The Antivenin is preferably given intramuscularly in the region of the antero-lateral thigh, so that a tourniquet may be applied in the event of a systemic reaction this equine-derived product. One dose of antivenin usually is adequate, but a second dose may be necessary in some cases. A small amount of Normal Horse Serum or the Antivenin may first be injected subcutaneously to test for sensitivity (allergy) to horse serum.
Market: The 2007 Average Wholesale Price (AWP) is $32.40/vial, and the Direct Cost (Manufacturer’s discount) is $25.90/vial (no change from 2004) (Red Book, 2007).
Companies involvement:
Full monograph
909 Antivenin (Latrodectus mactans)
Nomenclature:
Antivenin (Latrodectus mactans) [TR FDA]
Black Widow Spider Antivenin, Equine Origin [SY]
NDC 0006-4084-00 [NDC]
FDA Class: Biologic PLA
Year of approval (FDA) = 1936
Date of 1st FDA approval = 19360213
(in format YYYYMMDD)
Index Terms:
antibodies (see also immune globulins; monoclonal antibodies)
antivenins
biopharmaceutical products
blood products
equine immune globulins <!-- immunoglobulins -->
equine materials used
immune globulins, equine <!-- immunoglobulins -->
black widow spiders
equine plasma/serum
Latrodectus mactans
plasma proteins, immunoglobulin-depleted
spider venom, black widow
lyophilized (freeze-dried)
Sterile Diluent for Antivenin
thimerosal (mercury derivative)
approval dates uncertain (FDA reports erroneous, conflicting, or simply has lost the original approval dates) (FDAapproved)
EU200 Currently Approved in EU
UM001 Marketed Product in US
US200 Currently Approved in US
EM001 Marketed Product in EU
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