Jongen, J.L., Huijsman, M.L., Jessurun, J., Ogenio, K., Schipper, D., Verkouteren, D.R., . . . Vissers, K.C. (2013). The evidence for pharmacologic treatment of neuropathic cancer pain: Beneficial and adverse effects. Journal of Pain and Symptom Management, 46, 581–590.e1.

STUDY PURPOSE: To evaluate the evidence regarding beneficial and adverse effects of pharmacologic treatment of neuropathic cancer pain

TYPE OF STUDY: Systematic review

DATABASES USED: PubMed and EMBASE before August 2012; additional studies were identified from study reference lists.

KEYWORDS: Complete search terms are provided.

INCLUSION CRITERIA: Studies involving adult patients with cancer receiving oral analgesics

EXCLUSION CRITERIA: Not specified

TOTAL REFERENCES RETRIEVED = 653

EVALUATION METHOD AND COMMENTS ON LITERATURE USED: American Academy of Neurology evidence classification was used. Authors calculated the absolute risk benefit as the number of patients who received 30%–50% improvement divided by the total number of patients in the treatment group. The fraction of patients who dropped out because of adverse events also was determined. Pain reduction scores were calculated as the percentage of pain reduction from baseline in the study.

• FINAL NUMBER STUDIES INCLUDED = 30
• SAMPLE RANGE ACROSS STUDIES = 1–218
• TOTAL PATIENTS INCLUDED IN REVIEW = 2,267
• KEY SAMPLE CHARACTERISTICS: Not provided

APPLICATIONS: Palliative care

The proportion of patients who obtained improvement of pain with antidepressants was 0.55 (95% CI 0.40–0.69), with anticonvulsants was 0.57 (95% CI 0.44–0.69), with opioids was 0.95 (95% CI 0.93–0.96), and with other adjuvant medications was 0.45 (95% CI 0.33–0.57). Effects for patients with mixed pain were similar. The proportion of patients who withdrew because of adverse effects was 12.6% with antidepressants, 5% with anticonvulsants, 6% with opioids, and 6% with other adjuvant medications.

A substantial proportion of patients achieved pain reduction with adjuvant pain medications, and the proportion of patients who had benefit was higher than those who had to withdraw from studies because of adverse effects. The highest benefit was seen with opioids.

• Whether non-opioids were given in combination with opioids is unclear in this review.
• Controlled and uncontrolled studies were included.
• Many studies were determined to be of low quality.

Numerous limitations in this review make it difficult to evaluate the relative benefits of various approaches evaluated for management of neuropathic pain. Findings do suggest that results with all types of coanalgesics used appear to have benefits that outweigh the prevalence of adverse effects. Findings continue to support the effect and benefits of opioids as a mainstay of pain management for mixed and neuropathic pain.