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

Tan Tock Seng Hospital40 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

Conditions

Postcraniotomy Pain

Interventions

Eligibility

Sex: ALLMin age: 21 YearsMax age: 70 Years

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

To determine the difference in the mean pain VAS scores in the oxycodone and codeine groups at 24hr.

Time frame: 24hr post-op.

Secondary Outcomes

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.

Time frame: Up to 72hrs post-op.