Table 1.

Randomised, double-blind, placebo-controlled trials of different drugs in painful polyneuropathy.

Drug class / Pain condition / Trial
Reference number / Active drug / Daily dose / Design / Outcome / Improved on active / Improved on placebo
Antidepressant
Tricyclic
Diabetic neuropathy / 9 / Imipramine / 100 mg / Cross-over / imi > pla / 7/12 / 0/12
Diabetic neuropathy / 8 / Nortriptyline / 30 mg / Cross-over / nor > pla / 16/18 / 1/18
Diabetic neuropathy / 10 / Amitriptyline / Average 90 mg / cross-over / ami > pla / 15/29 / 1/29
Diabetic neuropathy / 11 / Imipramine / Average 200 mg / Cross-over / imi > pla / 17/19 / 3/20
Diabetic neuropahty / 15 / Clomipramine / 75 mg / Cross-over / clo > pla / 10/19 / 1/19
Diabetic neuropathy / 15 / Desipramine / 200 mg / Cross-over / desi > pla / 7/19 / 1/19
Diabetic Neuropathy / 17 / Desipramine / Average 201 mg / Cross-over / desi > pla / 11/20 / 2/20
Diabetic neuroapthy / 12 / Imipramine / 150 mg / cross-over / imi > pla / 8/18 / 2/18
Polyneuropathy / 16 / Amitriptyline / 75 mg / cross-over / ami > pla / 22/33 / 8/33
Polyneuropathy / 16 / Maprotiline / 75 mg / Cross-over / mapr > pla / 14/33 / 8/33
HIV neuropathy / 23 / Amitriptyline / Up to 100 mg / parellel / ami = pla / 23/46 / 24/56
SSRI
Diabetic neuropathy / 11 / Paroxetine / 40 mg / Cross-over / par > pla / 10/20 / 3/20
Diabetic neuropathy / 14 / Fluoxetine / 40 mg / Cross-over / flu = pla / 22/46 / 19/46
Diabetic neuropathy / 18 / Citalopram / 40 mg / cross-over / cit > pla / 3/15 / 1/15
Ion channel blocker

Antiarrhythmic

Diabetic neuropathy / 20 / Mexiletine / 10 mg/kg / cross-over / mex > pla / No dichotomous data
Diabetic neuropathy / 25 / Mexiletine / 225/450/675 mg / parellel / mex = pla / No dichotomous data
Diabetic neuropathy / 22 / Mexiletine / 600 mg / parallel / mex = pla / No dichotomous data
Diabetic neuropathy / 21 / Mexiletine / 225/450/675 mg / parallel / bmex > pla / 23/31 / 20/31
HIV neuropathy / 23 / Mexiletine / Up to 600 mg / Parallel / mex = pla / 22/48 / 24/50
HIV neuropathy / 24 / Mexiletine / 300/600 mg / cross-over / mex = pla / No dichotomous data

Anticonvulsant

Diabetic neuropathy / 27 / Carbamazepine / 200–600 mg / Cross-over / car > pla / 28/30 / 19/30
Diabetic neuropathy / 28 / Phenytoin / 300 mg / cross-over / phen > pla / 28/38 / 10/38
Diabetic neuropathy / 29 / Phenytoin / 300 mg / cross-over / phen = pla / No dichotomous data
Diabetic neuropathy / 32 / Gabapentin / 3600 mg / Parellel / gaba > pla / 47/79 / 25/76
Diabetic neuropathy / 33 / Gabapentin / 900 mg / cross-over / gaba = pla / 17/40 / 9/40
NMDA antagonist
Diabetic neuropathy / 34 / Dextrometh. / average 381 mg / cross-over / dext > pla / 7/13 / 0/13
Capsaicin
Diabetic neuropathy / 39 / cream / 0.075 % qid / Parallel / caps = pla / 17/24 / 11/22
Diabetic neuropathy / 40 / cream / 0.075 % qid / Parallel / caps > pla / 17/19 / 11/22
Diabetic neuropathy / 41 / cream / 0.075 % qid / Parallel / caps > pla / 65/91 / 57/111
Diabetic neuropathy / 42 / cream / 0.075 % qid / parallel / caps > pla / 6/10 / 2/10
Diabetic neuropathy / 43 / cream / 0.075 % qid / Parallelc / caps = pla / 23/39 / 26/39
Opioid
Diabetic neuropathy / 35 / Tramadol / 100-400 mg / parellel / tram > pla / a 43/63 / 23/64
Polyneuropathy / 36 / Tramadol / 200-400 mg / cross-over / tram > pla / 11/34 / 3/33
Levodopa
Diabetic neuropathy / 37 / Madopar / 300 mg / parellel / mad > pla / a8/14 / 3/11

SSRI = selective serotonin reuptake inhibitor

a additional data provided by author or from poster presentation

b Only the highest dose level significantly better than placebo

c Placebo on one leg and capsaicin on the other