Download PDF: Classification of evidence for neuropathic pain drug treatments
Treatment options for neuropathic pain available in Ireland
Table 1: Classification of evidence for drug treatments in commonly studied neuropathic pain (NP) conditions and recommendations for use1
| Aetiology | Recommendations
for first line |
Recommendations
for second or third line |
| Diabetic NPa | Duloxetine
Gabapentin Pregabalinb TCA Venlafaxine ER |
Opioidsc
Tramadold |
| PHN | Gabapentin
Pregabalinb TCA Lidocaine plasterse |
Capsaicin
Opioidsc |
| Classical
trigeminal neuralgia |
Carbamazepine
Oxcarbazepinef |
Surgery (or consider lamotrigine) |
| Central paing | Gabapentin
Pregabalinb TCA |
Cannabinoids (MS)
Lamotrigine Opioidsc Tramadol (SCI) |
ER, extended release; MS, multiple sclerosis; PHN, post-herpetic neuralgia; SCI, spinal cord injury; TCA, tricyclic antidepressants. Only drugs used at repeated dosages are shown here (with the exception of treatments with long- lasting effects such as capsaicin patches). Treatments are presented in alphabetical order.
a: Diabetic neuropathy was the most studied. Only TCA, tramadol and venlafaxine were studied in non-diabetic neuropathies.
b: Pregabalin has pharmacokinetic advantages compared to gabapentin (twice daily dosing, dose-dependent efficacy) but has similar efficacy and tolerability based on meta-analyses.
c: Strong opioids are recommended as second/third line despite established efficacy in neuropathic non-cancer pain because of potential risk for abuse on long-term use, as there are still too few long-term safety trials in neuropathic pain.
d: Tramadol may be considered first line in patients with acute exacerbations of pain especially for the tramadol/acetaminophen combination, or in patients with predominant co-existing non-NP.
e: Lidocaine is recommended in elderly patients, especially if concerned about CNS side-effects of oral dugs.
f: Oxcarbazepine may be preferred to carbamazepine due to less potential for drug interaction.
g: Cannabinoids (positive effects in MS) and lamotrigine (positive effects in CPSP but negative results in MS and SCI except in patients with incomplete lesion and brush-induced allodynia in one study based on post hoc analysis) are proposed for refractory cases.
Table 2 – Classification of evidence for drug treatments in less commonly studied neuropathic pain (NP) conditions.
| Aetiology of NP | Level A rating
for efficacy |
Level B rating
for efficacy |
| HIV neuropathy | Capsaicin 8% patch
Smoked cannabis |
Lamotrigine |
| Post-traumatic
or post-surgical NPa |
Amitriptyline*
Botulinum toxin-A* |
|
| Chronic radiculopathyb | ||
| Cancer NP | Gabapentin | Amitriptyline*
Tramadol* |
| Phantom pain | Morphine
Tramadol |
|
| Multi-aetiology NPc | Bupropion
Cannabinoids (oromucosal, synthetic analogue) Levorphanol |
Methadone
TCA (nortriptyline, clomipramine) |
ER, extended release; TCA, tricyclic antidepressants. Treatments are presented in alphabetical order.
a: Gabapentin was found to improved several secondary outcomes and may also be beneficial (level A) in a subgroup of patients
b: TCA/opioids combination was effective on maximal pain only in one study
c: Other drugs were found effective in some spontaneous NP symptoms (gabapentin) or only on brush-induced or static mechanical allodynia (mexiletine, venlafaxine) in single trials.
* Drugs marked with an asterisk were found effective in single class II studies
Combination
Three class I studies found a superiority of the gabapentin- opioids (morphine, oxycodone) and gabapentin/ nortriptyline combinations compared to each drug alone in patients with diabetic PN including Post- Herpetic Neuralgia (PHN) in two studies. A small study suggested superiority of the gabapentin/venlafaxine combination compared with gabapentin and placebo.
=> Combination therapy (level A for gabapentin combined with opioids or TCA) is recommended for patients who show partial response to drugs administered alone.
Reference: 1- Attal N et al. EFNS guidelines on the pharmacological treatment of neuropathic pain: 2010 revision. Eur J Neurol. 2010 17(9):1113-1123.