PAIN+ CPN

Drug treatments can help people with pain from damaged nerves (neuropathic pain)

This Evidence Summary is based on the following systematic review:

Finnerup NB, Attal N, Haroutounian S, et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol. 2015;14:162-73.

Review questions

In adults with painful nerve damage (neuropathic pain), which drugs reduce pain?

Background

Neuropathic pain happens when there are problems with the nerves and they send pain signals to the brain. It is different from pain from injuries or burns, and there are several causes. Neuropathic pain could result from an injury or a disease that affects the nervous system like shingles or diabetes. Several oral and topical (creams or lotions applied to affected areas of skin) drugs can reduce pain.

How the review was done

The researchers did a systematic review, searching for randomized controlled trials published in journals or reported in trial registries up to January 2014.

They found 229 randomized controlled trials.

The key features of the studies were:

  • people were of any age and had neuropathic pain caused by a lesion or disease of the nervous system, including postherpetic neuralgia (pain after having shingles) , diabetic and nondiabetic painful polyneuropathy, pain after amputation, neuropathic pain after trauma or surgery, central pain after stroke, spinal cord injury pain, or pain associated with multiple sclerosis;
  • drugs were compared with placebo; and
  • people were followed for 3 to 24 weeks.

What the researchers found

127 of the trials studied people with diabetic painful polyneuropathy or postherpetic neuralgia.

There was low to high quality evidence on the efficacy of the drugs to reduce pain.

The cause of neuropathic pain did not affect the benefit.

The authors recommended:

  • tricyclic antidepressants, serotonin-noradrenaline reuptake inhibitors, pregabalin, and gabapentin as first-line treatment (strong recommendation);
  • lidocaine patches, capsaicin high-concentration patches, and tramadol as second-line treatment (weak recommendation);
  • strong opioids and botulinum toxin A as third line treatment (weak recommendation); and
  • topical agents and botulinum toxin A for peripheral neuropathic pain (that is, in the legs or arms) only.

Conclusions

Many drug treatments reduce pain in people with neuropathic pain.

Effect of drug treatments versus placebo on pain relief in people with neuropathic pain

TreatmentNumber of trials (number of people)Rate of pain relief with active treatment*Rate of pain relief with placebo*Absolute effect of treatment
Tricyclic antidepressants15 trials (948 people)46%18%About 28 more people out of 100 had less pain
Serotonin-noradrenaline reuptake inhibitors10 trials (2541 people)43%28%About 15 more people out of 100 had less pain
Pregabalin25 trials (5940 people)38%24%About 14 more people out of 100 had less pain
Gabapentin or gabapentin extended-release and enacarbil14 trials (3503 people)35%20%About 15 more people out of 100 had less pain
Tramadol6 trials (741 people)46%27%About 19 more people out of 100 had less pain
Strong opioids7 trials (838 people)49%26%About 23 more people out of 100 had less pain
Capsaicin 8%6 trials (2073 people)36%27%About 9 more people out of 100 had less pain
Botulinum toxin A4 trials (137 people)60%6%About 54 more people out of 100 had less pa

*The event rate refers to the proportion of people who had at least a 50% reduction in pain after treatment.

This Evidence Summary was originally prepared for the McMaster Optimal Aging Portal.

Published: Friday, July 28, 2017