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

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 question

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.

Conclusion

Many drug treatments reduce pain in people with neuropathic pain.

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

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