Double-blind, Randomized Controlled Study to Assess the Analgesic Effect of 2 g of Magnesium Dipyrone (Metamizol) and Changes in Plasma Beta-endorphin Immunoreactivity Values in Patients Undergoing Elective Inguinal Herniorrhaphy Under Epidural Anesthesia.

Antonio Martín Duce

Status and phase: Completed; Phase 4

Conditions: Hernia Surgery; Pain; Dipyrone; Beta-endorphin

Treatments: Biological: beta-endorphin immunoreactivity; Drug: Dipyrone administration; Behavioral: Pain assessment; Other: Placebo administration

Study type: Interventional

Funder types: Other

Identifiers

NCT04595877

1093-10

Details and patient eligibility

About

A double-blind, randomized controlled study is designed to assess the analgesic effect of a single intravenous dose of 2 g of magnesium dipyrone (metamizol) and whether the administration of the active drug will be associated with changes in plasma beta-endorphin immunoreactivity values in patients undergoing elective inguinal herniorrhaphy (Bassini operation) under epidural anesthesia. Participants, care givers, and those assessing the outcomes will be blinded to group assignment. Participants will be randomized to receive dipyrone or a placebo. The active drug or placebo will be administered as an intravenous infusion over 10 min. Pain will be evaluated by the patient according to a 100-mm visual analogue scale. Assessments will be carried out the day before surgery, immediately after operation, at the time of drug administration, and 60 and 180 min after treatment. At the same time as pain will be evaluated, blood samples will be drawn for plasma beta-endorphin immunoreactivity measurement (immunoradiometric assay).

Enrollment: 60 patients

Sex: All

Ages: 18 to 70 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• 18-70 years, elective surgery, routine laboratory tests (blood cell count, biochemical profile, urinalysis), chest radiography, twelve-lead electrocardiography, body mass index (BMI), blood pressure, pulse rate normal or abnormal values without clinical relevance and a mental status sufficient to be able to complete efficacy tests.

Exclusion criteria

• Patients who had taken other analgesics or anti-inflammatory drugs 24 h before surgery, as those with known hypersensitivity to the drug or with any other disorder contradicting the administration of dipyrone. Patients with hypersensitivity to non-steroidal anti-inflammatory agents.

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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60 participants in 2 patient groups, including a placebo group

Dipyrone group

Experimental group

Description:

Dipyrone 2 g (Nolotil®, Europharma, Madrid, Spain); one ampoule in 50 mL of 0.9% saline solution as an intravenous infusion over 10 min.

Treatment:

Behavioral: Pain assessment

Drug: Dipyrone administration

Biological: beta-endorphin immunoreactivity

Placebo group

Placebo Comparator group

Description:

The placebo will be matched to the study drug for, color, and size. Placebo will be administered in a single dose in 50 mL of 0.9% saline solution as an intravenous infusion over 10 min.

Treatment:

Behavioral: Pain assessment

Other: Placebo administration

Biological: beta-endorphin immunoreactivity