antivenin, Centruroides (scorpion) (Rx)

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

Eye edema

Respiratory distress

Contraindications

None listed by manufacturer

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 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.

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

Onset (time to resolution of symptoms): 1.91 hr (adults); 1.28 hr (children); 4 hr (>95% of patients)

Half-life: 159 hr

Clearance: 83.5 mL/hr

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