Many patients with cancer pain have pain not fully controlled on opioids (eg. morphine). The addition of acetaminophen (Tylenol) to opioids in a small study in cancer patients demonstrated better pain control without an increase in side effects. This study will determine if regular acetaminophen improves pain control when added to strong opioids in patients with cancer pain.
Aim: To assess whether regular oral acetaminophen can reduce pain in cancer patients already on a strong opioid regimen. Rationale: It is estimated that 75% of people with advanced cancer suffer significant pain. Many of these people continue to have pain despite being on strong opioids. The rationale behind adding an additional analgesic with a different mechanism of action is to attempt to improve analgesia without increasing side effects. Overview: This is a double blind, randomised placebo-controlled, crossover trial to evaluate whether the addition of regular acetaminophen can reduce pain in cancer patients already on a strong opioid regimen. The study will be performed in ambulatory cancer patients who have pain that is believed to be caused by their cancer, and who have already been stabilised on an opioid regimen of \> 60mg/day of morphine equivalents. Each patient will be randomly allocated to receive either acetaminophen 1g qid or an identical appearing placebo qid for a seven-day period, and then crossed over to the other arm for a further seven-day period. Patients will complete daily pain diaries and weekly questionnaires (Brief Pain Inventory) and comparison will be made between the pain scores for the two treatment periods. Patient preference for the two treatment periods will also be evaluated. Research Question: A randomised, double-blind, placebo controlled crossover trial to determine if the addition of regular acetaminophen (1g PO qid) leads to improved analgesic control in adult cancer patients at Princess Margaret Hospital, who are already on strong opioids (\> 60mg morphine equivalents/day) as evaluated by daily pain scores measured by Numerical Rating Scales (NRS) and the Brief Pain Inventory (BPI). Hypothesis: Regular acetaminophen improves pain control in cancer patients who are already on strong opioid regimens.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
12
acetaminophen 1g po qid
acetaminophen 1g po qid for 7 days
Sydney Cancer Centre
Sydney, New South Wales, Australia
Princess Margaret Hospital
Toronto, Ontario, Canada
Patient preference for the acetaminophen or the placebo arm as assessed by asking the patient whether he/she preferred treatment period 1 or treatment period 2
Time frame: Post completion of period 2
Differences in the mean pain intensity score as assessed by the daily average Numeric Rating Scale (NRS) pain score during the week given acetaminophen compared with the daily average NRS pain score during the week given placebo
Time frame: post period 2
Symptoms possibly associated with acetaminophen use for each period using an NRS: feeling sick (nausea and vomiting)
Time frame: post period 2
drowsiness
Time frame: post period 2
constipation
Time frame: post period 2
cold sweats
Time frame: post period 2
overall sense of well being
Time frame: post period 2
Total analgesic consumption in each treatment period
Time frame: post period 2
Best and worst pain scores for each treatment period
Time frame: post period 2
Pain relief obtained in each treatment period
Time frame: post period 2
Effect of pain on functional ability
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Time frame: post period 2
Strength of preference for acetaminophen versus placebo on a 5-point scale
Time frame: post period 2
Proportion of patients who had a preference for acetaminophen who perceived the improvement warranted taking the additional tablets
Time frame: post period 2
Proportion of patients having a clinically significant improvement in pain (defined as an improvement in mean NRS of at least 33% during the week taking acetaminophen)
Time frame: post period 2