EFFECTS OF NEUROTROPIN® ON POST-HERPETIC NEURALGIA: DOUBLE-BLIND PLACEBO-CONTROLLED CLINICAL TRIAL

*K. Dan (1) and H. Yamamura (2)
(1) Fukuoka Tokusyukai Hospital, Fukuoka, Japan; (2) Kosaikai Hospital, Tokyo, Japan

Introduction:
Neurotropin® (NT), a non-protein extract from inflamed rabbit dermis inoculated with vaccinia virus that has been shown to facilitate descending pain inhibitory system in animal studies, is widely used for the treatment of chronic pain in Japan and China. It has been reported that NT tablets cured neuropathic pain such as Post-Herpetic Neuralgia (PHN) and Complex Regional Pain Syndrome I and II. To clarify the efficacy of NT on PHN, we conducted a randomized, double-blind, placebo-controlled clinical study of NT tablets in the treatment of PHN at
27 pain clinics in Japan.
Method:
Patients with PHN were instructed to take two tablets of NT or Placebo (PL) orally twice a day for 4 weeks (NT group: 111 patients; PL group: 117 patients). The intensity of pain was evaluated as severe (intolerable), moderate (capable of self care but work significantly affected), mild (tolerable), slight (so mild that it is occasionally forgotten) and nil at 0, 2, and 4 weeks of treatment. The patients also recorded pain relief, mood improvement, and sleeping status during the trial, and the data were calculated as scores.
Results:
NT improved the pain intensity score, pain relief score, total mood improvement, and sleep rating score at 4 weeks, as shown below.

Moderate improvement or better (%)

A global improving rating of moderate improvement or better was obtained in 40.4% (NT) and 18.6% (PL) of patients at 4 weeks (p<0.01, x²-test). No significant adverse reactions were observed in the NT-group, compared with the PL group.

Conclusion:
NT tablet is considered to be a useful medication for the treatment of PHN.

Corresponding Author: K. Dan, MD., Fukuoka Tokusyukai Hospital, 4-5, Sukukita, Kasuga-shi, Fukuoka, Japan 816-0864, Fax +81-92-573-1733, Tel: +81-92-573-6622