Sanderson, C., Quinn, S.J., Agar, M., Chye, R., Clark, K., Doogue, M., . . . Spruyt, O. (2015). Pharmacovigilance in hospice/palliative care: Net effect of gabapentin for neuropathic pain. BMJ Supportive and Palliative Care, 5, 273–280. 

To quantify immediate and short-term benefits and harms of gabapentin in hospice and palliative care patients

Data recorded at baseline, day 7, and day 21 were obtained from participating sites for patients receiving gabapentin for neuropathic pain. Benefits and harms factors were predefined by an expert committee. Overall benefit was defined as a one-point reduction in the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE), and harms were attributed to gabapentin if the day 7 data showed higher CTCAE scores. The Naranjo Scale was used to determine attribution to the drug itself in scores above three.

• N = 127   
• MEDIAN AGE = 68 years
• AGE RANGE = 26–89 years
• MALES: 80%, FEMALES: 20%
• CURRENT TREATMENT: Not applicable
• KEY DISEASE CHARACTERISTICS: 95.3% of patients had cancer.

• SITE: Multi-site   
• SETTING TYPE: Multiple settings    
• LOCATION: Australia

• PHASE OF CARE: End-of-life care
• APPLICATIONS: Palliative care 

• Prospective cohort

• National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE)
• Charlson Comorbidity Index (CCI)

Data were available at day 21 in 69 patients. Of these, 78% had improvement in their pain and 32% had associated harms. The most frequent harms were somnolence, cognitive disturbance, and fatigue. Twenty-nine patients had medication stopped or dosages reduced. The total number of patients who had benefit without harms was 9.4%. Regression analysis showed higher odds ratio of harm associated with comorbidities (p = 0.013).

Only 9% of palliative care/hospice patients receiving gabapentin had benefit for pain control without any associated harms.

• Risk of bias (no control group)
• Risk of bias (no blinding)
• Risk of bias (no random assignment)
• Unintended interventions or applicable interventions not described that would influence results 
• Measurement validity/reliability questionable
• Subject withdrawals ≥ 10%
• High missing data
• Other interventions used for pain were not accounted for in the analysis, which could have contributed to harms identified

Gabapentin is a common adjuvant pain medication. Findings from this study suggest that relatively few patients achieve benefits without harms. This study has multiple design and reporting limitations; however, it does raise the question of relative benefits of this medication in the hospice/palliative care population. Further well designed research to further evaluation risk/benefits of gabapentin are warranted. Nurses need to be aware of potential harms from various medications and monitor patient responses for appropriate care to identify and reduce harms. Potential for harm from gabapentin may be of greater concern among patients with multiple comorbid conditions.