Comparison of the Efficacy of Oral Oxycodone and Oral Codeine in the Treatment of Postcraniotomy Pain

Study Overview
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Brief Summary
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The efficacy of codeine is dependent on its demethylation to morphine. This extent of demethylation has wide inter-individual variability, making codeine's efficacy as a analgesic variable. Oxycodone is a semi-synthetic opioid and is a weak agonist on mu opioid receptors. Codeine has been the mainstay of analgesia for patients after craniotomy for many years. Traditionally, craniotomies were not thought to be very painful procedures, hence the use of codeine, a moderately potent opioid (when compared to morphine). However, in recent years, it has been found that up to 70% of post-craniotomy patients have moderate to severe pain and codeine did not provide adequate analgesic relief. Many studies have compared codeine to other drugs such as PCA morphine, fentanyl and tramadol, and patients on these stronger opioids generally had lower pain scores and better satisfaction. No study has been conducted to determine the efficacy of analgesia of oral oxycodone to oral codeine. Hence, the hypothesis is that oxycodone is more effective than codeine in providing pain relief in post-craniotomy patients.

Official Title
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Comparison of the Efficacy of Oral Oxycodone and Oral Codeine in the Treatment of Postcraniotomy Pain

Conditions
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Postcraniotomy Pain

Intervention / Treatment
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* Drug: Oxycodone
* Drug: Codeine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ages 21-70 years of age Planned elective craniotomy ASA 1-3 GCS 15 pre and post-op Able to understand and use the visual analogue scale Exclusion Criteria: Patients with GCS < 15 pre and/or post-op. Patients who are unable to quantify pain according to VAS scale. Patients who will be left intubated post-op. Contraindications and/or allergies to any of the trial drugs. Patients with renal and/or hepatic impairment. Patients with decreased respiratory reserves. Patients with post-op cognitive dysfunction.

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Codeine<br>Oral Codeine 60mg 6hrly/prn | Drug: Codeine<br>* Oral Codeine 60mg 6hrly/prn<br>* Other names: Codeine Phosphate;|
| Active Comparator: Oxycodone<br>Oral Oxycodone 5mg 6hrly/prn | Drug: Oxycodone<br>* Oral Oxycodone 5mg 6hrly/prn<br>* Other names: Oxynorm Immediate Release;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine the difference in the mean pain VAS scores in the oxycodone and codeine groups at 24hr. |  | 24hr post-op. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To look at the incidence of adverse events in the oxycodone and codeine groups. | To compare the incidence of excessive sedation, respiratory depression and GCS; to compare the pain VAS scores at 48 and 72hrs post-op; to compare the mean satisfaction scores at 24 and 72hrs post-op. | Up to 72hrs post-op. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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analgesic efficacy, oral codeine, oral oxycodone, postcraniotomy