Comparison between neurotropin and mepivacaine for stellate ganglion injection.

Neurotropin, a nonproteinaceous extract from the inflamed skin of rabbits inoculated with vaccinia virus, is reported to decrease pain effectively when used for stellate ganglion (SG) injection. We compared the effects of neurotropin SG injection with those of mepivacaine on pain relief, as well as comparing the side effects. One hundred and eighty-eight SG injections in 15 patients (5 with postherpetic neuralgia and 10 with sudden deafness) were performed either with 1% mepivacaine 6 ml or with neurotropin 3 ml combined with saline 3 ml in turn. Fifteen min before and after the injection, the pain score, according to a visual analog scale (VAS; only in patients with postherpetic neuralgia); blood pressure; and heart rate were checked, and the number of procedures with Horner's sign was determined. VAS scores decreased significantly with both injections. Horner's sign was observed on the block side in all procedures with the mepivacaine injection, but it was seen in only 48 procedures with the neurotropin injection. Blood pressure and heart rate did not change. In conclusion, the SG injection of neurotropin decreased the VAS score in postherpetic neuralgia to the same extent as mepivacaine. The incidence of Horner's sign was significantly lower with neurotropin than with mepivacaine.