Article Figures & Data
Figures
- Figure 1.
Production of series 1 and 2 prostaglandins from linoleic acid.
Tables
Trial Design Number R/C Dose Duration(mo) Outcome* Jamal & Carmichael,15 R,DB,PL 22/22 360 mg qd 6 Significant improvement 1990 Symptom scores (−2.1 vs 0.9) Median MCV (1.4 vs −1.4) Peroneal MCV (1.9 vs −0.1) Median CMAP (1.0 vs −0.7) Peroneal CMAP (0.7 vs −0.3) Median (1.8 vs −1.7) Sural SNAP (0.4 vs −1.5) Ankle HT (°C) (−2.3 vs 0.5) Wrist HT (°C) (−0.5 vs 0.02) Not significant Sign scores Ankle, wrist CT (°C) Keen et al,16 1993 R,DB,PL 111/84 480 mg qd 12 Significant improvements Median MCV (2.4 vs −2.1) Peroneal MCV (2.2 vs −1.9) Extensor digitorum brevis CMAP (1.2 vs −0.6) Thenar CMAP (1.4 vs −1.1) Median SNAP (2.4 vs −1.3) Sural SNAP (1.7 vs −1.0) Wrist HT (°C) (0.8 vs −0.4) Wrist CT (°C) (0.8 vs −0.3) Arm tendon reflex (2.9 vs −12.0) Leg tendon reflex (17.7 vs 0.5) Arm sensation (6.9 vs −7.3) Leg sensation (15.0 vs −8.4) Arm muscle strength (4.9 vs −7.4) Not significant Ankle HT and CT (°C) Leg muscle strength Purewal et al,17 1997 R,DB,PL 51/51 480 mg qd 12 Not significant Vibratory threshold at hallux R=randomized, DB=double-blind, PL = placebo-controlled, C=number of patients completing trial, MCV=median conduction velocity, CMAP=compound muscle action potential, SNAP=sensory nerve action potential, HT = heat threshold, CT=cold threshold.
* Numbers in parenthesis indicate significant difference compared with placebo in favor of evening primrose oil.
Trial Design Number R/C Dose Duration Outcome* Ziegler et al,25 199524 R,DB,PL 328/260 100, 600, or 1,200 mg qd parenteral ALA 3 wk Significant improvements HPAL—600/1,200 (−1.4/−1.2 vs −0.5) HPAL NDS—1,200 (−1.8 vs −1.0) PGE—600 (76% vs 46%) Not significant HPAL—100; NDS—100/600 PGE—100/1,200 Reljanovic et al,26 R,DB,PL 299/169/65† 600 or 1,200 mg qd 2 y Significant improvements 1999 oral ALA Sural SNCV—600/1,200 (3.0/3.8 vs −0.1) Sural SNAP—600 (0.3 vs −0.7) Tibial MNCV—1,200 (1.2 vs −1.5) Not significant Sural SNAP—1,200; tibial MNCV—600 Tibial MNDL—600/1,200; NDS—600/1,200 Ziegler et al,27 199924 R,DB,PL 503/377 600 mg qd parenteral ALA (3 wk) then 1,800 mg qd oral ALA (6 mo) OR
600 mg qd parenteral ALA (3 wk) then oral placebo (6 mo) OR
Parenteral placebo (3 wk) then oral placebo (6 mo)
6 mo Significant improvements NIS—3 wk (−4.3 vs −3.5) NIS-LL—3 wk (−3.3 vs −2.8)Not significant TSS—3 wk/6 mo NIS—6 mo; NIS-LL—6 mo Ruhnau et al,28 R,DB,PL 24/22 1,800 mg qd oral ALA 3 wk Significant improvements 1999 TSS (−3.8 vs −1.9) NDS (−0.3 vs 0.2) Not significant HPAL R=randomized, DB=double-blind, PL = placebo-controlled, C=number of patients completing trial, HPAL=Hamburg pain adjective list, NDS=neuropathy disability score, PGE=physician’s global evaluation based on a rating scale of change in pain severity, SNCV=sensory nerve conduction velocity, SNAP=sensory nerve action potential, MNCV=motor nerve conduction velocity, MNDL=motor nerve distal latency, NIS=neuropathy impairment score, NIS-LL = neuropathy impairment score–lower limb, TSS=total symptom score.
* Numbers in parenthesis indicate significant difference compared with placebo in favor of ALA.
† Although 169 patients completed the trial, data from only 65 patients were used because of problems with data collection.
Trial Design Number R/C Dose Duration (wk) Outcome* Chad et al,36 1990 R,DB,PL 58/46 0.075% cap qid 4 Significant improvements VAS-R (71 vs 41%) Not significant VAS-P PGE Scheffler et al,32 1991 R,DB,PL 54/49 0.075% cap qid 8 Significant improvements PGE (90 vs 50%) VAS-P (49 vs 17%) VAS-R (66 vs 39%) Capsaicin Study Group,37 R,DB,PL 277/219 0.075% cap qid 8 Significant improvements 1991 PGE (71 vs 51%) VAS-P (40 vs 28%) VAS-R (60 vs 45%) Tandan et al,38 1992 R,DB,PL 22/20 0.075% cap qid 8 Significant improvements PGE (60 vs 20%) Not significant VAS-P VAS-R Low et al,39 1995† R,DB,PL 40/39 0.075% cap qid 12 Not significant PGE VAS-P VAS-R Note: R=randomized, DB=double-blind, PL = placebo-controlled, C=number of patients completing trial, VAS-R=visual analogue scale for pain relief, VAS-P=visual analogue scale for pain severity, PGE=physician’s global evaluation based on a rating scale of change in pain severity.
* Numbers in parenthesis indicate significant difference in favor of capsaicin compared with placebo.
† Only 12% of patients enrolled in this trial had diabetes.
