Diabetics may develop this condition after uncontrolled diabetes over a long term. Symptoms score include stabbing pain, burning pain, paresthesia, and asleep numbness.
Alpha-lipoic acid and diabetic peripheral neuropathy:
There is evidence to suggest that alpha-lipoic acid (ALA), an antioxidant, reduces neuropathic pain in patients with diabetes. Participants in a study were randomized to IV administration of either ALA (600 mg) (n = 60) or placebo (n = 60) for 5 days/week for a total of 14 treatments. At the end of the study, the total symptom score in patients taking ALA had improved by an average of 4.8 points, compared to an improvement of only 1.8 points in the placebo group. Compared to the placebo group, the treatment group had evidence of significant improvement in pain, numbness while asleep, prickling, neuropathy signs, and overall measure of effectiveness. (20)
In a double-blind, placebo-controlled trial,181 patients with diabetic peripheral neuropathy were given either placebo or one of 3 doses of lipoic acid: 600, 1200 or 1800 mg daily. Over the five week study period, benefits were seen in all three lipoic acid groups as compared to the placebo group. Average total symptom score (TSS) (including stabbing pain, burning pain, paresthesia, and asleep numbness of the feet) improved by 51% in ALA600, 48% in ALA1200, and 52% in ALA1800 compared with just 32% in the placebo group. Rates for those experiencing a 50% or more reduction in TSS was 62% (ALA600), 50% (ALA1200), 56% (ALA1800), and 26% (placebo). Participants experienced increased symptoms of nausea, vomiting, and vertigo as the dose of ALA increased. (21)
A review of studies found that among diabetes patients with peripheral neuropathy, a problem with the nerves that can produce pain, loss of sensation, and an inability to control muscles, alpha lipoic acid was found to significantly reduce neuropathic pain. Alpha lipoic acid, a fatty acid, is also an antioxidant found naturally inside every cell in the body. It’s needed by the body to produce the energy for the body’s normal functions. Researchers found that alpha lipoic acid was associated with an average total symptom scores reduction of 2.26. Specifically, when given orally the reduction was 1.78 and when administered by IV the reduction increased to 2.81. There is also evidence that alpha lipoic acid decreases neuropathic pain when given for a period of 3 weeks at a dose of 600 mg/day (grade of recommendation A). However, it is unclear whether the benefits seen after the oral administration of alpha lipoic acid over 3-5 weeks at a dose of >600 mg/day are clinically relevant. (22)
A meta-analysis of 15 randomized controlled trials found that IV administration of 300-600 mg/day α-lipoic acid (ALA) for 2-4 weeks for treatment of diabetic peripheral neuropathy (DPN), a problem with the nerves that can produce pain, loss of sensation, and an inability to control muscles, was associated with a significant improvement in nerve conduction velocity and neuropathic symptoms. ALA was associated with an average benefit for median motor nerve conduction velocity (MNCV) of 4.63, median sensory nerve conduction velocity (SNCV) of 3.17, for peroneal MNCV, 4.25, and 3.65 for peroneal SNCV. (23)
Capsaicin and peripheral neuropathy:
In a study by Anand et al, a topical skin patch with 8% capsaicin placed for 1 hour was successful at producing pain relief at the site of peripheral neuropathy for up to 12 weeks. The mechanism of action was proposed to be defunctionalized peripheral nerve function. There was determined to be a low risk of both adverse systemic reaction and drug interactions. (46)
A review of studies on the use of capsaicin cream for pain relief was conducted. Six studies (n=389) were identified examining low dose (0.075%) capsaicin cream versus placebo. Low dose topical capsaicin was ineffective for pain without significant effect beyond placebo. Studies showed skin reactions could result in withdrawal and were more common with capsaicin than placebo though this became better with time. Adverse effects were rare systemically. (47)
The high dose, 8% capsaicin patch was studied in a similar fashion on postherpetic neuralgia by Irving et al. The patch was also found to be effective at pain relief for 12 weeks. (48)
References:
20.Ametov AS, Barinov A, Dyck PJ, et al. The sensory symptoms of diabetic polyneuropathy are improved with alpha-lipoic acid: the SYDNEY trial. Diabetes Care. 2003;26:770-776. http://www.ncbi.nlm.nih.gov/pubmed/12610036
21.Ziegler D, Ametov A, Barinov A, et al. Oral Treatment With alpha-lipoic Acid Improves Symptomatic Diabetic Polyneuropathy: The SYDNEY 2 trial. Diabetes Care . 2006;29:2365-2370. http://care.diabetesjournals.org/content/29/11/2365.abstract
22.Mijnhout GS, Kollen BJ, Alkhalaf A, Kleefstra N, Bilo HJ. Alpha lipoic Acid for symptomatic peripheral neuropathy in patients with diabetes: a meta-analysis of randomized controlled trials. Int J Endocrinol. 2012;2012:456279. http://www.ncbi.nlm.nih.gov/pubmed/22331979
23.Han T, Bai J, Liu W, Hu Y. A systematic review and meta-analysis of α-lipoic acid in the treatment of diabetic peripheral neuropathy. Eur J Endocrinol. 2012 Oct;167(4):465-71. http://www.ncbi.nlm.nih.gov/pubmed/22837391
46.Anand P, Bley K. Topical capsaicin for pain management: therapeutic potential and mechanisms of action of the new high-concentration capsaicin 8% patch. Br J Anaesth. 2011 Oct;107(4):490-502. doi: 10.1093/bja/aer260. Epub 2011 Aug 17. http://www.ncbi.nlm.nih.gov/pubmed/21852280
47.Derry S, Moore RA. Topical capsaicin (low concentration) for chronic neuropathic pain in adults. Cochrane Database Syst Rev. 2012 Sep 12;9:CD010111. http://www.ncbi.nlm.nih.gov/pubmed/22972149
48.Irving GA, Backonja MM, Dunteman E, Blonsky ER, Vanhove GF, Lu SP, Tobias J; NGX-4010 C117 Study Group. A multicenter, randomized, double-blind, controlled study of NGX-4010, a high-concentration capsaicin patch, for the treatment of postherpetic neuralgia. Pain Med. 2011 Jan;12(1):99-109. http://www.ncbi.nlm.nih.gov/pubmed/21087403
See More:
Effectiveness of different benfotiamine dosage regimens in the treatment of painful diabetic neuropathy
Winkler G, Pál B, Nagybéganyi E, Ory I, Porochnavec M, Kempler P
Arzneimittelforschung 1999 Mar;49(3):220-4
PMID: 10219465
Abstract
The therapeutic effectiveness of a benfotiamine (CAS 22457-89-2)-vitamin B combination (Milgamma-N), administered in high (4 x 2 capsules/day, = 320 mg benfotiamine/day) and medium doses (3 x 1 capsules/day), was compared to a monotherapy with benfotiamine (Benfogamma) (3 x 1 tablets/day, = 150 mg benfotiamine/day) in diabetic patients suffering from painful peripheral diabetic neuropathy (DNP). In a 6-week open clinical trial, 36 patients (aged 40 to 70 yrs) having acceptable metabolic control (HbA1c < 8.0%) were randomly assigned to three groups, each of them comprising 12 participants. Neuropathy was assessed by five parameters: the pain sensation (evaluated by a modified analogue visual scale), the vibration sensation (measured with a tuning fork using the Riedel-Seyfert method) and the current perception threshold (CPT) on the peroneal nerve at 3 frequencies: 5, 250 and 2000 Hz). Parameters were registered at the beginning of the study and at the end of the 3rd and 6th week of therapy. An overall bneneficial therapeutic effect on the neuropathy status was observed in all three groups during the study, and a significant improvement in most of the parameters studied appeared already at the 3rd week of therapy (p < 0.01). The greatest change occurred in the group of patients receiving the high dose of benfotiamine (p < 0.01 and 0.05, resp., compared to the othr groups). Metabolic control did not change over the study. It is concluded that benfotiamine is most effective in large doses, although even in smaller daily dosages, either in combination or in monotherapy, is effective.