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Completed

NCT Number: NCT06886230

Ondansetron vs. Dexamethasone for Postoperative Nausea

This randomized controlled trial aims to evaluate the safety and efficacy of Ondansetron, Dexamethasone, and their combination in managing postoperative nausea and vomiting (PONV) in patients undergoing surgery under anesthesia. A total of 100 patients will be randomized into four groups: Placebo, Ondansetron, Dexamethasone, and Ondansetron-Dexamethasone combination. The primary outcome will be the incidence of PONV within 24 hours post-surgery, while secondary outcomes include severity of symptoms, need for rescue medication, adverse effects, and patient satisfaction.

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Key information

Conditions

Postoperative Nausea and Vomiting (PONV) Nausea Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Complications Postoperative Nausea and Vomiting Signs and Symptoms Signs and Symptoms, Digestive Vomiting

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Federal Government Polyclinic (Postgraduate Medical Institute)

Islamabad, Capital, 051, Pakistan

About this study

Postoperative nausea and vomiting (PONV) is a common and distressing complication following surgery, affecting patient recovery and satisfaction. This study aims to compare the safety and effectiveness of Ondansetron, Dexamethasone, and their combination for PONV prevention.

The study will be conducted as a randomized, controlled trial at Federal Polyclinic Hospital Islamabad over four months. A total of 100 adult patients undergoing elective surgery under anesthesia will be enrolled and randomly allocated into one of four groups (n=25 each):

Placebo group - Receives no prophylactic antiemetic treatment. Ondansetron group - Receives 4 mg IV Ondansetron before surgery. Dexamethasone group - Receives 8 mg IV Dexamethasone before surgery. Ondansetron-Dexamethasone group - Receives 4 mg IV Ondansetron + 8 mg IV Dexamethasone before surgery.

Methodology:

Patients will be assessed at multiple time points (2, 4, 6, 12, and 24 hours postoperatively) for PONV incidence and severity, along with the need for rescue medication. Side effects such as headache, dizziness, hypertension, and hyperglycemia will also be monitored.

Statistical Analysis:

Data will be analyzed using chi-square tests and ANOVA to compare outcomes across treatment groups. A p-value < 0.05 will be considered statistically significant.

This study will help determine the most effective and safest antiemetic regimen, guiding clinical decision-making for better PONV management.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult patients (≥18 years) scheduled for elective surgery under anesthesia.
  • Patients at moderate to high risk for postoperative nausea and vomiting (PONV), as determined by an Apfel risk score ≥2.
  • Patients able to provide informed consent or have a legally authorized representative provide consent.

Exclusion criteria

  • Known allergy or hypersensitivity to Ondansetron, Dexamethasone, or any of their components.
  • History of significant adverse reactions to previous PONV prophylaxis with Ondansetron or Dexamethasone.
  • Pre-existing conditions or medications contraindicating the use of Ondansetron or Dexamethasone, e.g. QT prolongation or severe cardiac arrhythmias (e.g., torsades de pointes, congenital long QT syndrome), Uncontrolled hypertension (for Dexamethasone use), Severe hepatic impairment (Child-Pugh C) or end-stage renal disease, Uncontrolled diabetes mellitus (due to Dexamethasone-induced hyperglycemia).
  • Patients with active malignancy undergoing chemotherapy or radiotherapy.
  • Pregnant or lactating women (unless safety in this population is specifically being studied).
  • Chronic opioid users (≥3 months of continuous opioid use), as this may alter PONV risk and response to prophylaxis.

Treatment and study plan

Placebo (normal saline)

Drug

Patients in this group will receive an intravenous (IV) injection of normal saline before surgery. This serves as a control group to compare the efficacy of active treatment groups in preventing postoperative nausea and vomiting.

Other names: Saline Injection, Inert Solution

ondansetron (Zofran)

Drug

Patients in this group will receive a single intravenous (IV) dose of Ondansetron 4 mg before surgery. Ondansetron is a selective 5-HT3 receptor antagonist commonly used to prevent nausea and vomiting associated with anesthesia and surgery.

Other names: Zofran, Ondem, Emeset

Dexamethasone

Drug

Patients in this group will receive a single intravenous (IV) dose of Dexamethasone 8 mg before surgery. Dexamethasone is a corticosteroid with anti-inflammatory properties that has been shown to reduce the incidence of PONV by modulating inflammatory pathways and neuroreceptor activity.

Other names: Decadron, Dexasone

Primary outcomes

  1. Incidence of Postoperative Nausea and Vomiting (PONV)

    Time frame: 24 hours

    Defined as the presence of nausea and/or vomiting at any assessment time point (recovery, 2, 4, 6, 12, and 24 hours postoperatively).

    Comparison of postoperative nausea and vomiting incidence between the Ondansetron-Dexamethasone and Ondansetron groups.

    The need for rescue antiemetic administration as an indicator of postoperative nausea and vomiting severity.

Secondary outcomes

  1. Severity of Postoperative Nausea and Vomiting (Postoperative Nausea and Vomiting Impact Scale Score)

    Time frame: 24 hours

    Assessment of the frequency, severity, and impact of nausea and vomiting on daily activities and quality of life.

    Measured using patient-reported responses to the Postoperative Nausea and Vomiting Impact Scale.

    Scoring Range: 0 to 6 Minimum Score (0): No impact of nausea or vomiting Maximum Score (6): Severe impact on daily activities Interpretation: Higher scores indicate a worse outcome, with greater severity and impact of PONV.

  2. Postoperative Pain Scores (Visual Analog Scale Score)

    Time frame: 24 hours

    Pain intensity recorded at recovery, 2, 6 and 24 hours postoperatively using the Visual Analog Scale. A 10-point scale ranging from 0 (no pain) to 10 (worst possible pain). Higher scores indicate greater pain severity.

    Comparison of pain levels between the two groups to determine any analgesic effects of dexamethasone.

  3. Need for Rescue Medication

    Time frame: 24 hours

    Frequency and timing of rescue antiemetic administration in both groups. Determines the effectiveness of the interventions in controlling postoperative nausea and vomiting.

  4. Adverse Effects of Medications

    Time frame: 24 hours

    Frequency of ondansetron-related side effects: headache, dizziness, constipation, diarrhea, fatigue, allergic reactions.

    Frequency of dexamethasone-related side effects: increased appetite, insomnia, mood changes, fluid retention, hypertension, hyperglycemia.

  5. Satisfaction with Postoperative Nausea and Vomiting Management

    Time frame: 24 hours

    Patient-reported satisfaction levels with nausea and vomiting management, measured using the satisfaction scale in the questionnaire.

    Each response is scored on a 5-point Likert scale, where:

    • = Very dissatisfied (minimum score)
    • = Somewhat dissatisfied
    • = Neutral
    • = Somewhat satisfied
    • = Very satisfied (maximum score) The total score ranges from 5 (minimum satisfaction) to 25 (maximum satisfaction), with higher scores indicating better patient satisfaction.

  6. Apfel Score: Risk Assessment for Postoperative Nausea and Vomiting (PONV)

    Time frame: 24 hours

    Apfel Score Components (Each Risk Factor = 1 Point) Female gender → (Yes = 1 point, No = 0 points) History of postoperative nausea and vomiting or motion sickness → (Yes = 1 point, No = 0 points) Non-smoker → (Yes = 1 point, No = 0 points) Planned use of postoperative opioid analgesia → (Yes = 1 point, No = 0 points) Higher Apfel Scores indicate an increased risk of postoperative nausea and vomiting.

  7. Heart Rate

    Time frame: 24 hours

    Heart rate (beats per minute) will be continuously monitored and recorded at predefined intraoperative and postoperative time points to assess hemodynamic stability and detect potential bradycardia or tachycardia.

  8. Blood Pressure

    Time frame: 24 hours

    Systolic and diastolic blood pressure (measured in mmHg) will be recorded at regular intraoperative and postoperative intervals to monitor hemodynamic stability and detect episodes of hypotension or hypertension.

  9. Respiratory Rate

    Time frame: 24 hours

    Respiratory rate (measured in breaths per minute) will be monitored intraoperatively and postoperatively to evaluate respiratory function and detect potential respiratory depression or distress.

  10. Oxygen Saturation

    Time frame: 24 hours

    Oxygen saturation levels (SpO₂, measured as a percentage) will be continuously monitored throughout the intraoperative and postoperative periods to assess respiratory function and detect hypoxia.

Sponsors and collaborators

Lead sponsor

Hafiz Muhammad Hamza

Other

Collaborators

  • Federal Government Polyclinic (Postgraduate Medical Institute)

Registry information

Official study title

Assessing The Safety and Efficacy of Ondansetron, Dexamethasone, and Their Combined Regimen in Managing Post Operative Nausea and Vomiting: A Randomized Controlled Trial

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Mar 20, 2025
Registry last updated
Jun 17, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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