Raptis, E., Vadalouca, A., Stavropoulou, E., Argyra, E., Melemeni, A., & Siafaka, I. (2014). Pregabalin vs. opioids for the treatment of neuropathic cancer pain: A prospective, head-to-head, randomized, open-label study. Pain Practice, 14, 32–42.

To determine the efficacy and safety of increasing opioid doses versus increasing doses of an adjuvant for patients with definite neuropathic cancer pain (i.e., neuropathic pain that occurred as a result of the disease, the treatment, or both). The goal was to achieve a 30% or more decrease in the visual analog scale (VAS) score compared to baseline.

One hundred and twenty patients were divided via simple randomization into two groups. Baseline data were collected on all 120 patients (i.e., VAS score, meds, and full assessment). The first group was prescribed a starting dose of pregabalin at 75 mg per day and titrated up by 75 mg every third day as needed up to 600 mg per day divided into two doses, until adequate pain relief was achieved or adverse effects were noted. The second group was given 25 mcg per hour fentanyl patch and increased by 25 mcg per hour every 72 hours up to a max dose of 150 mcg per hour until adequate pain relief was achieved or adverse events were noted. Both groups had rescue oral morphine as needed.

• N = 120  
• AGE = Older than 18 years
• MEAN AGE = Pregabalin group: 61.2 years (SD = 9.3 years); fentanyl group: 63.2 years (SD = 11.8 years)
• MALES = 58, FEMALES = 62
• KEY DISEASE CHARACTERISTICS: Diagnosed with definite neuropathic cancer pain
• OTHER KEY SAMPLE CHARACTERISTICS: On second step of the World Health Organization analgesic ladder; resistant to a combination of codeine with paracetamol; a non-steroidal anti-inflammatory drug and methylprednisolone used for a minimum of three consecutive days; expected survival of two months or longer; normal renal function and a VAS score greater than 4 at baseline

• SITE: Single site   
• SETTING TYPE: Not specified   
• LOCATION: Athens, Greece

• PHASE OF CARE: Mutliple phases of care
• APPLICATIONS: Elder care, palliative care

• Prospective, head-to-head, comparative, randomized, open-label

• Satisfaction Criterion (created by the authors for this study), which intended to define the level of pain relief considered appropriate for the study patients
•  VAS

Changes in VAS scores showed no difference between groups, but the percentage change in these scores showed a significant reduction for the patients on pregabalin (-58% versus -50%). A greater percentage of patients on pregabalin achieved the study primary endpoint of at least a 30% reduction in pain VAS score (73.3% with pregabalin, 36.7% with fentanyl, p < .0001). No significant difference was seen in the proportion of patients needing rescue medication.

For these patients with neuropathic pain, no significant differences were seen in efficacy of adjuvant pregabalin versus increasing opioid medication for pain control.

• Authors created their own measurement tool.
• Baseline VAS analysis was different between the two groups, with baseline  median pain lower in the opioid group—this could have made the defined reduction easier.
• Short timeframe (four weeks)
• The interventions compared involved two different routes of medication administration.
• The dose limit on fentanyl (150 mcg per hour) was based on the groups’ pain center protocol, which dictates that patients on more than 150 mcg per hour fentanyl would need to be considered for a different treatment or intervention.
• Limited information on any adverse events experienced by study participants
• No information about the amount of rescue medication used in both groups, only the proportion of patients that used any rescue medication

I find the results of this study to be useful for oncology professionals working with patients with neuropathic cancer pain, whether from the disease, the treatment, or both. A similar study using tramadol versus pregabalin for neuropathic cancer pain may be of value.