I often say I hate the term neuropathy because it assumes they can all be treated similarly. Now three trials using Topiramate in Diabetic peripheral neuropathy have failed to show benefit. – yet one using less strick response criteria has…
One of the plenary speakers at the IASP meeting in Montreal 2010 displayed a litany of trials that failed in neuropathy. The topiramate one stood out:
three negative trials:
Topiramate in painful diabetic polyneuropathy: findings from three double-blind placebo-controlled trials. The Topiramate Diabetic Neuropathic Pain Study Group†,
U. Thienel1, W. Neto2,S. K. Schwabe2, U. Vijapurkar2yet
Acta Neurologica Scandinavica. Volume 110, Issue 4, pages 221–231, October 2004
“After 18–22 weeks of double-blind treatment, pain reductions were numerically greater with topiramate in two studies but differences between topiramate and placebo in VAS scores or in the secondary efficacy endpoints did not reach statistical significance in any of the three studies”
They did comment that study design might have got in way…
Yet a positive trial here:
Topiramate vs placebo in painful diabetic neuropathy Analgesic and metabolic effects
P. Raskin, MD, P. D. Donofrio, MD, N. R. Rosenthal, MD, D. J. Hewitt, MD, D. M. Jordan, BSN, J. Xiang, PhD and A. I. Vinik, MD, PhD for the CAPSS-141 Study Group abstract here
- 12 weeks of topiramate
- treatment reduced PVA scale score (from 68.0 to 46.2 mm) more effectively than placebo (from 69.1 to 54.0 mm; p = 0.038).
- “Fifty percent of topiramate-treated subjects and 34% of placebo-treated subjects responded to treatment, defined as >30% reduction in PVA scale score (p = 0.004).
- Topiramate monotherapy also reduced worst pain intensity (p = 0.003 vs placebo) and sleep disruption (p = 0.020 vs placebo).
- Diarrhea, loss of appetite, and somnolence were the most commonly reported adverse events in the topiramate group.
- Topiramate reduced body weight (–2.6 vs +0.2 kg for placebo; p < 0.001) without disrupting glycemic control. “
Comment – well, not a sterling recommendation for topiramate but might work if you set your sites for only a 30% improvement. Weight loss in a diabetic might be a draw…
Topiramate in back pain got a so-so response as well – more about its level of side effects (though they titrated up fast):
Topiramate in Chronic Lumbar Radicular Pain
A preliminary report of these results was presented at the Tenth World Congress on Pain, San Diego, California, August 19, 2002.
Suzan Khoromi, Athos Patsalides†, Suzan Parada‡, Vesta Salehi, Jennifer M. Meegan, Mitchell B. Max
Journal of Pain Volume 6, Issue 12, Pages 829-836 (December 2005) abstract here
- crossover trial of topiramate (50 to 400 mg) and diphenhydramine (6.25 to 50 mg) as active placebo
- topiramate cut leg pain by a mean of 19% (P = .065). (not statistically significant)
- Global pain relief was assessed on a 6-level category scale and was significantly better on topiramate (P < .005)
- There conclusions – “We concluded that topiramate treatment might reduce chronic sciatica in some patients but causes frequent side effects and dropouts. We would not recommend topiramate unless studies of alternative regimens showed a better therapeutic ratio.”
Looks like you need a cast iron stomach and brain to take it (at least titrated fast…)