Post-Herpetic /Shingles Neuralgia – Benefits of Local B12 Injections

Two separate chinese articles discuss use of B12 in the period immediately after shingles  and also, in a separate study, later. Each shows benefit. Note should be made that they used methylcobalamin – the bioactive form of B12

• Randomized for 4 weeks to either
  – methylcobalamin injection (N = 33) – 1 mg/day into multiple shingles areas subcutaneously,
  – oral methylcobalamin 500 ug three times daily (N = 33),
  –  subcutaneous 1.0% lidocaine injection (N = 32)
• Their description of technique:
  “Local subcutaneous injection was administered once daily every morning, between 8 and 11 o’clock, six times per week, for 4 weeks. Using sterile hypodermic (25 gauge)
  needles and syringes, 0.5 mL each liquid agent was injected at up to four painful areas of torso, based on the subjects’ report of their pain experience”

Response – B12 – over a 40% improvement with subcutaneous injection including B12 over those given lidocaine subcut. Oral B12 at large dose FAILED to give any response.

Next article:

Wang, M.
Efficacy of intradermal lidocaine mixture injection combined with oral drugs for the treatment of postherpetic neuralgia in elderly patients
Pain Clin J. June 2012, 8(3), 180-183
http://www.cqvip.com/Read/Read.aspx?id=43157206

• Article in non-copy-able Chinese so only have abstract
• Post Herpetic Neuralgia more than 3 months since onset – 25 elderly cases
• mixture included lidocaine, methycobal(B12), and normal saline (sorry – no information on strength – any chinese readers help out here?)
• Injections were in involved dermatomal area
• Medications used as well, were tramadol and amitriptyline
• Severe cases were injected every other day and others “every second day” – which I presume they meant every 3rd day
• 22/25 had significant relief at 1, 2 and 4 weeks complemented by fact sleep improved
• 3 abandoned shots because of pain (I suspect some would be facial as I would use infra and supraorbital blocks in these cases and found some could not tolerate them)
• They felt this was a safe and effective treatment regimen for elderly patients

Comment – Even at high dose, oral B12 had no effect . I always neutralize my lidocaine with a little 8.4% sterile Sodium Bicarbonate to stop the stinging. In the first article, plain lidocaine injections had no effect so it would seem, the B12 was the useful agent in the second study. Although tramadol might do in some cases, I use hydromorph contin, initially at night, and then throughout day. It has the advantage of being in small long-lasting granule form so patient can open capsule and start with a small amount and work up. Short acting hydromorphone could be used during day at small dose until a full capsule is tolerated at night. Amitriptyline is not well tolerated in elderly and pregabalin/lyrica could be tried:

Sabatowski, R., Gálvez, R., Cherry, D. A., Jacquot, F., Vincent, E., Maisonobe, P., … & The, 1. 0. S. G. (2004).
Pregabalin reduces pain and improves sleep and mood disturbances in patients with post-herpetic neuralgia: results of a randomised, placebo-controlled clinical trial.
Pain, 109(1-2), 26-35.  free article here

5% lidocaine patches or 5- 10% lidocaine in lipoderm would be useful. ( Note – lipoderm is less irritating than prior PLO gels).
Nerve blocks help.
Don’t forget to use Vitamin C.
Tons of other options documented in my blog:
http://painmuse.org/?cat=46