We have frequently obtained good results with difficult pain using an improved acupuncture anesthesia method, cutaneous meridian stimulation, in which the patients himself can administer stimulation. However we have had a great variety of experience using these methods. There have even been cases in which therapy had no effect whatsoever. It has long been known that the effects of stimulation produced analgesia, (SPA) one form of acupuncture anesthesia, vary remarkably from person to person.
In one hand it has been indicated that the pain-killing effects are related with the endogenous morphine-like substances however recently Takeshige and colleagues, believing that the individual differences in effect are based on the activity of the individual's amino peptidase, administered the peptidase interferrent, D-phenylalanine (DPA) and proved experimentally that so doing causing a change from ineffective to effective in SPA results.
We studied the effects produced by DPA on the cutaneous pain threshold using transcutaneous nerve stimulation, by administering DPA in cases in which the pain threshold did not rise due to transcutaneous electric nerve stimulation alone. The subjects of the study were 9 healthy volunteers between the ages of 24-30 with no neurological diseases and 8 stubborn pain patients. The stimulation points were 2, right LI-4 and right LI-10. Stimulation was administered using a spike-type conductor rubber external electrode.
Results
1. Looking at changes in the pain threshold due to transcutaneous electric nerve stimulation only, it was observed that in 11 of 17 cases there was almost no change or slight fluctuation around the pain threshold.
2. Upon administering 4g. DPA to the 6 cases in which the pain threshold did not change and administering transcutaneous electric nerve stimulation in the same manner as before, the threshold rose in 1 case.
3. The serum concentration of phenylalanine increased 5 times that of pre-medication levels.

This study aimed to estimate the cost-effectiveness of pregabalin treatment for neuropathic pain.
Design:Long-term simulations based on state transition models.
Methods:We examined the cost-effectiveness of pregabalin for treatment of three common peripheral neuropathic pains, postherpetic neuralgia(PHN), painful diabetic peripheral neuropathy(DPN), and radiculopathy, using the incremental cost-effectiveness ratio(ICER). We used quality-adjusted life years(QALYs)as an index of effectiveness, and also estimated medical costs. For PHN and DPN, we constructed state transition models comprising two states, with and without pregabalin treatment, and performed 52-week simulations. The pain scores reported in Japanese phaseIII studies were used to set patients' weekly pain scores. The results of utility surveys conducted overseas were used as utility scores, while values randomly sampled from probability distributions were used to set weekly pain scores and drop-out rates. In base-case analyses, we performed 1000 1st-order Monte Carlo simulations using 1000 values randomly sampled from probability distributions, and calculated QALYs and medical costs for 52 weeks for each group. For radiculopathy, the ICER was calculated from changes in QALYs for 12 weeks reported overseas and medical costs estimated separately for the identical period.
Results:The ICERs for PHN, DPN, and radiculopathy were 1,116,886 Yen/QALY, 1,100,420 Yen/QALY, and 1,095,943 Yen/QALY, respectively, which were well below the upper limits of ICER ranges for treatments considered cost-effective. There were no cases in which ICERs obtained from scenario and sensitivity analyses differed significantly.
Conclusion:Pregabalin was shown to be cost-effective treatment for neuropathic pain.