Axelsson, B., Stellborn, P., & Strom, G. (2008). Analgesic effect of paracetamol on cancer related pain in concurrent strong opioid therapy. A prospective clinical study. Acta Oncologica, 47, 891–895.

To empirically explore whether omitting paracetamol was clinically feasible in concurrent strong opioid therapy when treating incurable patients with cancer receiving palliative home care

Researchers assessed the difference in pain control in patients initially on a strong opioid in combination with paracetamol, over a four-day period, versus a strong opioid alone without paracetamol. Patients were asked to estimate their pain intensity at baseline, and then to stop paracetamol. If pain increased, patients were to take an extra dose of the opioid. If this was not effective, the paracetamol was restarted.

• The study reported on a sample of 34 patients.
• Median patient age was 68 years (range = 48–88 years).
• The sample was 53% male and 47% female.
• Prostate, pancreatic, breast, gynecologic, and bladder cancer were the most common patient diagnoses.
• Pain was classified as nociceptive (56%), neuropathic (15%), and mixed (29%).
• Median dose of strong opioids was 90 mg morphine equivalents every 24 hours.

• Multisite
• Home setting
• Three palliative homecare teams in Sweden

The study used a prospective, descriptive, cohort design.

• Numeric rating scale (0–10)
• Interview

Only six patients (18%) wanted to continue with regular paracetamol, while 10 appreciated the opportunity to take paracetamol only as needed. There was no significant difference in average pain intensity with or without paracetamol. On day 4 at follow-up, 26% felt more pain, 6% felt less pain, and 68% reported no difference.

The study supported the hypothesis that a fair number of patients on strong opioids do as well without paracetamol.

• The study had a small sample, with less than 100 participants.
• The study occurred over a short interval of time.

The decision to utilize a combination of a strong opioid and paracetamol/acetaminophen should not necessarily be mandatory. It should be individualized for each patient, as there are patients who achieve pain control on the strong opioid alone, thus alleviating the need for additional medication in combination.