Assessment of the Efficacy of Scorpion Antivenom Therapy in a Dose-response Manner, in Patients With Scorpionism

Assessment of the Efficacy of Anti-scorpion Venom Therapy in a Dose-response Manner, Following the Principles of Rational Drug Use in Patients With Scorpionism: a Non-inferiority, Randomized, Double-blind, Controlled Clinical Trial

The clinical study aims to compare the effectiveness of applying two different regimens of scorpion antivenom therapy. In the first regimen (control), the medication is administered to all patients, and depending on the severity of the condition, the dosage varies. In the experimental regimen, an identical dose of scorpion antivenom is administered to patients exhibiting signs and symptoms of scorpion sting intoxication, in addition to pain and other symptoms at the sting site. The primary response variable is the time taken for signs and symptoms to resolve, but differences in complications, adverse effects, venom and antivenom concentration in the blood, and the need for other therapeutic measures are also evaluated.

Study Overview

• Status: Completed
• Conditions: Centruroides Envenomation
• Intervention / Treatment: Drug: Traditional scorpion antivenom regimen; Drug: Serial dose of scorpion antivenom regimen

• Study Type: Interventional
• Enrollment (Actual): 56
• Phase: Phase 2; Phase 3

Contacts and Locations

Study Locations

• Mexico
  • Jalisco
    • Tlaquepaque, Jalisco, Mexico, 45560
      • Servicios Médicos Municipales de San Pedro Tlaquepaque.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Individuals aged 18 or older presenting with a diagnosis of scorpionism to the emergency department.
• Treated solely with paracetamol, scorpion antivenom, saline solution, and local ice application.
• Any gender.
• Less than two hours elapsed since scorpion sting.
• Willing to participate in the study through written informed consent.

Exclusion Criteria:

• Allergies or contraindications to any of the study medications.
• Uncertainty regarding scorpion sting.
• Previous treatment by another physician.
• Intramuscular administration of scorpion antivenom due to urgent clinical conditions.
• Decision not to provide informed consent.
• Any limitations hindering the proper understanding of study participation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Traditional scorpion antivenom regimen; Active/placebo comparator	Drug: Traditional scorpion antivenom regimen; All patients will be classified according to two severity scales. The pharmacist, who is the only team member aware of which group each patient was assigned to, will consider the classification corresponding to the classification proposed by the Mexican Clinical Practice Guideline to decide the dose of scorpion antivenom. Scorpion antivenom will be administered to all patients. Patients in this group will receive between one and three vials every 30 minutes, depending on the severity of the condition (one vial for patients classified as grade I, two vials for patients classified as grade II, and three vials for patients classified as grade III)
Experimental: Serial dose of scorpion antivenom regimen	Drug: Serial dose of scorpion antivenom regimen; All patients will be classified according to two severity scales. The pharmacist, who is the only team member aware of which group each patient was assigned to, will consider the classification corresponding to the American classification to decide the dose of scorpion antivenom. Scorpion antivenom will be administered only in the presence of signs and/or systemic symptoms of intoxication, excluding signs and symptoms at the sting site. Patients in this group will receive between one and two vials every 30 minutes, depending on the severity of the condition (one vial for patients classified as grade III and two vials for patients classified as grade IV)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to resolution of signs and symptoms	Time to resolution of signs and symptoms from admission and from the estimated time of the sting	two and a half to five hours
Serum venom concentration	Serum venom concentration upon patient arrival, after administration of antivenom, and upon reporting the absence of signs of intoxication	two and a half to five hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mortality	Mortality rate of each group	two and a half to five hours
Length of intrahospital stay	Time from patient admission to discharge due to patient improvement	two and a half to five hours
Serum antivenom concentration	Scorpion antivenom concentration at five minutes after administration, prior to secondary doses, and prior to discharge	two and a half to five hours

Collaborators and Investigators

• Sponsor: Selene Guadalupe Huerta Olvera
• Investigators: Study Director: Selene G Huerta-Olvera, PhD, Medical & Life Sciences Department. La Ciénega University Center; Principal Investigator: Héctor A González-Ruiz, PhD student, Centro Universitario de Ciencias de la Salud

Publications and helpful links

General Publications

• Ziggelaar A. [The origin of the theory of harmonious vibrations. The father, Ignace Gaston Pardies (1636-1673). Studies on Ignace gaston Pardies I]. Dent Mag Oral Top. 1966 Apr;83(2):145-51. No abstract available. French.

Study record dates

Study Major Dates

• Study Start (Actual): June 15, 2024
• Primary Completion (Actual): November 1, 2025
• Study Completion (Actual): December 1, 2025

Study Registration Dates

• First Submitted: March 5, 2024
• First Submitted That Met QC Criteria: March 20, 2024
• First Posted (Actual): March 27, 2024

Study Record Updates

• Last Update Posted (Actual): December 17, 2025
• Last Update Submitted That Met QC Criteria: December 9, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Antivenom; Centruroides; Scorpion antivenom; Scorpion envenomation
• Additional Relevant MeSH Terms: Wounds and Injuries; Chemically-Induced Disorders; Poisoning; Bites and Stings; Scorpion Stings; Immunologic Factors; Physiological Effects of Drugs; Antivenins
• Other Study ID Numbers: Dosis Seriada de Alacramyn

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No