Use of Clonidine for Pain control in inguinal hernia surgery: a comparative clinical study

Efficacy and safety of Clonidine as an adjuvant in anesthesia in patients undergoing herniorrhaphy. A randomized, masked, non-inferiority clinical trial

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

REBEC

Registry ID

RBR-6fhbn39

Enrollment

Registered

2026-07-13

Start date

2024-02-01

Completion date

Unknown

Last updated

2026-08-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hernia, Inguinal Adjuvants, Anesthesia

Interventions

This is a randomized, masked, non-inferiority clinical trial. Patients will be randomized into two large groups according to anesthetic technique, local or spinal. Subsequently, each group will be sub

after consent, the Free and Informed Consent Form will be presented and, after signing, participants will be randomized to study groups. Patients and the surgeon will not be informed of their group al

only the anesthesiologist and data analyst will know each patient&apos

s group assignment. Intraoperative and postoperative data will be recorded and stored by the anesthesiologist. After the procedure, the anesthesiologist and surgeon will monitor the patient postoperat

Eligibility

Age

18 Years to 60 Years

Inclusion criteria

Inclusion criteria: Patients of both genders; ASA physical status classification I or II; aged between 18 and 60 years; body mass index less than 35 kg/m²; diagnosis of unilateral inguinal hernia; Nyhus classification types I, II, IIIa, IIIb, or IV; non-incarcerated and non-strangulated hernias

Exclusion criteria

Exclusion criteria: Documented hypersensitivity to clonidine or its components; bradyarrhythmia or atrioventricular block; severe cardiovascular disease or hemodynamic instability; renal insufficiency; cerebrovascular disease; coronary insufficiency; use of opioids in the preoperative period

Design outcomes

Primary

Measure	Time frame
Expected outcome 1: Lower postoperative pain was expected in patients undergoing herniorrhaphy using clonidine, assessed by the visual analog scale during the intraoperative, immediate postoperative, and late postoperative periods, comparing the experimental and control groups.;Observed outcome 1: No statistically significant difference was observed between groups regarding maximum pain intensity assessed by the visual analog scale, demonstrating equivalence between clonidine and the control group in pain control. However, a significantly longer pain-free period was observed in the clonidine group compared to the control group.	—

Measure

Time frame

Expected outcome 1: Lower postoperative pain was expected in patients undergoing herniorrhaphy using clonidine, assessed by the visual analog scale during the intraoperative, immediate postoperative, and late postoperative periods, comparing the experimental and control groups.;Observed outcome 1: No statistically significant difference was observed between groups regarding maximum pain intensity assessed by the visual analog scale, demonstrating equivalence between clonidine and the control group in pain control. However, a significantly longer pain-free period was observed in the clonidine group compared to the control group.

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Secondary

Measure	Time frame
Expected outcome 2: Safety of clonidine use was expected to be assessed based on the prevalence of vomiting, headache, hypotension, and other patient-reported adverse events during the intraoperative, immediate postoperative, and late postoperative periods.;Observed outcome 2: No statistically significant differences were observed between groups regarding complications. Two cases of delirium were recorded in each group. In the control group, four cases of facial pruritus and four cases of headache were also observed, events that did not occur in the clonidine group.;Expected outcome 3: Total medication costs per patient were expected to be evaluated, along with a comparative analysis of cost-effectiveness between the study groups.;Observed outcome 3: The mean total medication cost per patient was R$ 27.90 in the clonidine group and R$ 27.13 in the control group, with no statistically significant difference. The incremental cost-effectiveness ratio was approximately R$ 0.38 per additional pain-free hour, characterizing clonidine as a cost-effective intervention in the evaluated context.	—

Measure

Time frame

Expected outcome 2: Safety of clonidine use was expected to be assessed based on the prevalence of vomiting, headache, hypotension, and other patient-reported adverse events during the intraoperative, immediate postoperative, and late postoperative periods.;Observed outcome 2: No statistically significant differences were observed between groups regarding complications. Two cases of delirium were recorded in each group. In the control group, four cases of facial pruritus and four cases of headache were also observed, events that did not occur in the clonidine group.;Expected outcome 3: Total medication costs per patient were expected to be evaluated, along with a comparative analysis of cost-effectiveness between the study groups.;Observed outcome 3: The mean total medication cost per patient was R$ 27.90 in the clonidine group and R$ 27.13 in the control group, with no statistically significant difference. The incremental cost-effectiveness ratio was approximately R$ 0.38 per additional pain-free hour, characterizing clonidine as a cost-effective intervention in the evaluated context.

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Countries

Contacts

Public ContactPoolo Marcos de Souza

Instituto de Ensino e Pesquisa da Santa Casa de Misericórdia de Belo Horizonte - SCMBH

poolomarcos@hotmail.com+55-31-995406677

Outcome results

None listed

Source: REBEC (via WHO ICTRP) · Data processed: Aug 10, 2026