Dosing and uses of Anascorp (antivenin, Centruroides [scorpion])
Adult dosage forms and strengths
powder for injection
- <120mg total protein and >150 LD50 [mouse] neutralizing units/vial
Centruroides (Scorpion) Envenomation
Centruroides (scorpion) immune F(ab')2 (equine) injection; antivenom indicated for treatment of clinical signs of scorpion envenomation
Initiate treatment as soon as possible in patients who develop clinically important signs of scorpion envenomation, including but not limited to loss of muscle control, roving or abnormal eye movements, slurred speech, respiratory distress, excessive salivation, frothing at the mouth, and vomiting
Initial dose: Infuse contents of 3 vials IV over 10 minutes (see IV preparation); monitor for up to 60 minutes after completing infusion to determine if symptoms are resolved
Additional doses may be used if needed; infuse 1 vial at a time at 30-60 minutes intervals
Pediatric dosage forms and strengths
powder for injection
- <120mg total protein and >150 LD50 [mouse] neutralizing units/vial
Centruroides (Scorpion) Envenomation
Centruroides (scorpion) immune F(ab')2 (equine) injection; antivenom indicated for treatment of clinical signs of scorpion envenomation
Initiate treatment as soon as possible in patients who develop clinically important signs of scorpion envenomation, including but not limited to loss of muscle control, roving or abnormal eye movements, slurred speech, respiratory distress, excessive salivation, frothing at the mouth, and vomiting
Initial dose: Infuse contents of 3 vials IV over 10 minutes (see IV preparation); monitor for up to 60 minutes after completing infusion to determine if symptoms are resolved
Additional doses may be used if needed; infuse 1 vial at a time at 30-60 minutes intervals
Note: Most of the patients treated in clinical trials were children (78%), ranging in age from <1 month to 18.7 years
Anascorp (antivenin, Centruroides [scorpion]) adverse (side) effects
1-10%
Vomiting (4.7%)
Pyrexia (4.1%)
Rash (2.7%)
Nausea (2.1%)
Pruritus (2%)
Headache (1.9%)
Rhinorrhea (1.8%)
Myalgia (1.6%)
Fatigue (1.6%)
Cough (1.4%)
Diarrhea (1.3%)
Lethargy (1.1%)
<1%
Serum sickness (0.5%)
Postmarketing Reports
Chest tightness
Palpitation
Rash
Pruritus
Warnings
Contraindications
None
Cautions
Severe hypersensitivity reactions, including anaphylaxis, are possible; prepare for monitoring and management of allergic reactions, particularly with a history of hypersensitivity to equine proteins or who have received previous antivenins containing equine proteins
Readiness with IV therapy using epinephrine, corticosteroids, and diphenhydramine is recommended during the infusion
Delayed allergic reactions (serum sickness, 0.5% incidence) may occur; monitor with follow-up visit
Made from equine plasma and may contain infectious agents (eg, viruses)
Localized reactions and generalized myalgias reported with cresol, as an injectable excipient contained in Anascorp
Pregnancy and lactation
Pregnancy category: C; No human or animal data exist; use only if clearly needed
Lactation: Unknown whether distributed in breast milk; caution advised
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Anascorp (antivenin, Centruroides [scorpion])
Mechanism of action
Composed of venom-specific F(ab’)2 fragments of immunoglobulin G (IgG) that bind and neutralize venom toxins, facilitating redistribution away from target tissues and elimination from the body
Pharmacokinetics
AUC: 706 mcg•hr/mL
Vd (steady-state): 13.6 L
Half-life: 159 hr
Clearance: 83.5 mL/hr
Administration
IV Preparation
Reconstitute contents of each vial with 5 mL of sterile normal saline and mix by continuous gentle swirling
Initial infusion (ie, 3 vials): Combine contents of reconstituted vials promptly and further dilute to a total volume of 50 mL with sterile normal saline
Additional doses: Further dilute reconstituted vial to total volume of 50 mL with sterile normal saline
Inspect solution visually for particulate matter and discoloration prior to administration; do not use if turbid
IV Administration
Infuse IV over 10 minutes
Monitor patient closely during and up to 60 minutes following completion of infusion to determine if clinically important signs of envenomation have resolved
Storage
Available as a sterile, lyophilized preparation in a single-use viaL
Store at room temperature (up to 25 ºC [77 ºF])
Temperature excursions are permitted up to 40 ºC (104ºF)
Do not freeze
Discard partially used vials
