Table 1.

Evidence summary from meta-analysis as the basis for the updated NICE recommendations.³

Drug	Daily dose	Number needed to treat	95% Confidence interval	Number needed to harm	95% Confidence interval	Evidence quality	Safety profile	Number of trials in meta-analysis
Antidepressants
Amitriptyline	25–150 mg N.B. No evidence of a dose–response effect	3.6	3.0–4.4	13.4	9.3–24.4	Moderate		18
SNRIs	Duloxetine 20–120 mg Venlafaxine 150–225 mg	6.4 (combined)	5.2–8.4	11.8 (combined)	9.5–15.2	High		14
Anticonvulsants
Pregabalin	150–600 mg N.B. Dose–response gradient exhibited	7.7	6.5–9.4	13.9	11.6–17.4	High		25
Gabapentin	900–3600 mg N.B. No dose–response effect	6.3	5.0–8.3	25.6	15.3–78.6		Good	14
Gabapentin enacarbil (extended release)	1200–3600 mg N.B. No dose–response effect	8.3	6.2–13.0	31.9	17.1–230.0		Good	14
Topiramate				6.3	3.6–6.7		Poor
Zonisamide				2.0	1.3–4.6		Poor
Oxcarbazepine				5.5	4.3–7.9		Poor
Weak opioid agonist/SNRI
Tramadol/Tramadol extended release	Up to 400 mg	4.7	3.6–6.7	12.6	8.4–25.3	Moderate		7
Mu-opioid agonist/noradrenaline reuptake inhibitor
Tapentadol		10.2	5.3–185.5					2
Strong opioids	Oxycodone 10–120 mg Morphine 90–240 mg N.B. Maximum effectiveness associated with 180 mg morphine or equivalent	4.3 (combined)	3.4–5.8	11.7 (combined)	8.4–19.3	Moderate		13 N.B. Type of pain = mainly peripheral neuropathic
Capsaicin	8% patch (showed sustained efficacy compared with 0.04% cream)	10.6	7.4–18.8			High		7 N.B. Type of pain = post-herpetic neuralgia and HIV-related painful polyneuropathy
Botulinum	Botulinum toxin Aa 50–200 units (administered s.c. in the region of pain)	1.9	1.5–2.4				Good	6 N.B. Type of pain=peripheral neuropathic

NICE, National Institute for Health and Care Excellence; SNRI, selective serotonin and norepinephrine reuptake inhibitor.

^aPotent neurotoxin, may have analgesic effects by its action on neurogenic inflammation; a mechanism that may be involved in some peripheral neuropathic pain conditions.¹⁶.