IntraNasal Low Dose Ketamine For Neuropathic Pain

I have reluctant to use ketamine because of undesirable side effects including hallucinations. Now it looks like much can be achieved even with low dose using S isomer form.

Eur J Pain. 2010 Apr;14(4):387-94
Effects of low-dose intranasal (S)-ketamine in patients with neuropathic pain
Huge V, Lauchart M, Magerl W, Schelling G, Beyer A, Thieme D, Azad SC.   abstract here

• Article used S – isomer ketamine – 5- 8X more potent
• Annoyingly, the author did not explain his nasal spray but I did come across author using plain ketamine that did:
  Pain Volume 108, Issues 1-2, March 2004, Pages 17-27 Safety and efficacy of intranasal ketamine for the treatment of breakthrough pain in patients with chronic pain: a randomized, double-blind, placebo-controlled, crossover study
  Daniel B. Carr et al.    abstract here
  “study drug was formulated as a 10% aqueous solution of ketamine hydrochloride with 0.002% benzalkonium chloride (vehicle) in a nasal spray pump. The study drug was prepared to be applied intranasally using a 0.1 ml metered nasal spray pump attached to a 20 ml reservoir bottle. Each spray delivered a total of 10 mg of ketamine hydrochloride.”  They gave 1-5 sprays which I presume used both nostrils.
• Isomer article used 0.2 mg/kg- 0.4 mg (S)-ketamine per kilogram body weight. – that would be 14-28 mg for a 70 kg person. If made 10% S-ketamine then each 0.1 ml spray would be 10 mg – could scale down from there…
• Pain relief was as follows:
  
• side effects were less at lower dose and included:
  

Comment – Might be useful for bedtime sedation – pain relief so could sleep. Not sure would be that much use in daytime unless wasn’t working or driving. Just another option. Now, does anyone know anything about S isomer availability?