Tasmacioglu, B., Aydinli, I., Keskinbora, K., Pekel, A.F., Salihoglu, T., & Sonsuz, A. (2009). Effect of intravenous administration of paracetamol on morphine consumption in cancer pain control. Supportive Care in Cancer, 17, 1475–1481.

To examine the effectiveness of IV administration of paracetamol on the control of cancer pain and its possible contribution as reduction of opioid consumption

Patients were randomized to receive IV administration of saline (control) or 1 g of paracetamol on top of morphine.

• The study reported on a sample of 43 patients.
• Patient age range was 18–76 years. 
• Patients had chronic cancer pain without neuropathic origin; all had either somatic or visceral pain, but none had both types of pain.
• Patients had a visual analog scale (VAS) score of greater than 4, a Pain Rating Index (PRI) score greater than 10, and an Eastern Cooperative Oncology Group (ECOG) performance status score of less than 3.

• Single site
• Outpatient setting
• Pain clinic of Istanbul University

The study was double-blind, placebo-controlled, and randomized.

• VAS
• PRI
• ECOG performance status
• Statistical Package for Social Sciences (SPSS)
• Two-way ANOVA
• Chi-square test and Fisher’s exact test
• Paired sample t test
• Student t test
• Mann-Whitney U test or Wilcoxon sign test

Both treatments resulted in improved VAS and PRI scores compared to baseline. However, groups did not differ in terms of VAS and PRI scores, morphine consumption, side-effect frequencies, laboratory values, ECOG stats, and patient satisfaction. The study failed to confirm any benefits of add-on treatment with IV administration of paracetamol.

There was no benefit derived from adding IV paracetamol to morphine in an effort to enhance the effectiveness or contribute to reduction in opioid consumptions.

The study had a small sample.

This study further supports the growing body of evidence that adding paracetamol to an opioid does not necessarily improve pain control or minimize the need for opioid. Pain management needs to be individualized. Further study in this area is warranted.