Mercadante, S., Porzio, G., Aielli, F., Ferrera, P., Codipietro, L., Lo Presti, C., & Casuccio, A. (2013). The effects of low doses of pregabalin on morphine analgesia in advanced cancer patients. The Clinical Journal of Pain, 29, 15–19.

To evaluate the effectiveness of pregabalin as a coanalgesic on pain in patients with cancer-related pain

Patients were assigned randomly to receive either sustained-release morphine or sustained-release morphine and pregabalin in increasing doses up to 150 mg per day. Oral morphine in doses of about one-sixth of the baseline dose was used for breakthrough pain. Other drugs were allowed, and patients already receiving non-opioid analgesics of steroids, antidepressants, or anticonvulsants could continue use.

• N = 44
• MEAN AGE = 65.5 years (SD = 10.3 years)
• MALES: 55%, FEMALES: 45%
• KEY DISEASE CHARACTERISTICS: Not reported

• SITE: Multi-site
• SETTING TYPE: Outpatient
• LOCATION: Italy

• PHASE OF CARE: Late effects and survivorship

• RCT

• Brief Pain Inventory
• Pain intensity numeric rating scale
• Symptoms assessed on a 1–3 scale

No significant differences were seen between groups in pain intensity or symptoms. Pain declined overall in both study groups. In both groups, opioid dosage used over time significantly increased.

Findings did support improvement in chronic, uncontrolled pain with the use of pregabalin as a coanalgesic. Sample size was insufficient to analyze differences in neuropathic pain specifically.

• Small sample (less than 100)
• Risk of bias (no blinding)
• Subject withdrawals 10% or more

Findings did not show a benefit of adding pregabalin to strong opioids for improved management of uncontrolled cancer-related pain; however, the study had a small sample size because of loss of patients to follow-up–a typical challenge for studies in patients with advanced disease. Further research is needed into the appropriate role, dosage, and effective use of drugs such as pregabalin as coanalgesics.