NeuPSIG guidelines highlight recommended treatments for neuropathic pain
Recent neuropathic pain management guidelines have highlighted specific drugs to be used as first, second, and third line treatment of neuropathic pain, according to a presentation at the 7th Association of South-East Asian Pain Societies Congress (ASEAPS 2017) held in Yangon, Myanmar.
To update treatment recommendations for neuropathic pain, the Neuropathic Pain Special Interest Group (NeuPSIG) conducted a systematic review and meta-analysis of randomized, double-blind studies conducted between 1966 and 2013. [Lancet Neurol 2015;14:162-173]
Drugs with strong Grading of Recommendation Assessment, Development, and Evaluation (GRADE) were recommended as first-line treatment and included tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), pregabalin, gabapentin, and gabapentin extended release. Drugs with a weak GRADE and recommended for second-line therapy included topical lidocaine, capsaicin (8%), and tramadol, while drugs with a weak GRADE and recommended for third-line therapy were strong opioids and botulinum toxin type A.
“Strong opioids are generally considered third-line options, but may in some instances be used as second-line treatments,” said presenter Dr Troels Jensen from the Department of Neurology and Danish Pain Research Center at Aarhus University Hospital, Aarhus, Denmark. [ASEAPS 2017, plenary PL02]
The study also found strong evidence against the use of levetiracetam or mexiletine for neuropathic pain.
Combination therapy is an option if monotherapy demonstrates a lack of efficacy or adverse effects, or if combination therapy shows benefits. However, combination therapy does present several challenges including limited efficacy and an increase in adverse events. It is also difficult to identify an optimal dose ratio, said Jensen.
For example, one study found that the combination of morphine and nortriptyline for neuropathic pain was more beneficial over either drug as monotherapy. [Pain 2015;156:1440-1448]. Another study found that combining morphine and gabapentin produced better analgesic effects than either drug alone, [N Engl J Med 2005;352:1324-1334] while another study found that despite better efficacy with an imipramine-pregabalin combination over either drug as monotherapy, rate and severity of side effects were also higher in patients on combination therapy. [Pain 2015;156:958-966]
Criteria for an ideal pharmacological treatment include consistent outcome from high-quality trials, a relevant degree of pain relief for a sustained period, few (mild) side effects (efficacy outweighs adverse effects), effect on other parameters such as comorbidities, and low cost, said Jensen.
“There is no guideline in general that works for all patients,” said Jensen. “It is an individual decision and [pain physicians] have to make the decision together with the patients [as to] what will work best,” he said.