Vinblastin iontophoresis in treating intractable pain

A group of 36 patients were tested for the effects of percutaneous iontophoretic application of Vinblastin inj., a microtubular transport inhibitor (Gideon Richter, Hungary) in the treatment of chronic intractable pain. The group is divided into two subgroups: (1) 16 patients with persistent root pain following one or more operations for lumbar intervertebral disk herniation. (2) 20 patients with persistent pain in the area of the radicular skin zones or in the skin innervation areas of peripheral nerves. Vinblastin was injected in the place of maximal pain, 0.01% concentration in the total amount of 5 mg of active substance. The active electrode was the anode. There were at least 15 procedures per patient. The therapeutic effect was evaluated from the patients' subjective reports on pain relief in per cent, from the intensity of actual pain and from the interference of pain intensity with daily activities. Considering all the criteria, an improvement was achieved in 29 cases, i.e. 81%. The beneficial effect of the therapy was observed from the 8th to 10th application. In the first group of patients, 69% showed a clinically significant relief of the algetic symptoms. In the other group, the therapeutic effect was 90% of cases. A significant difference between both these groups was found to be in the degree of pain relief after the end of therapy. In the first group the average pain relief was 22.2%, in the other one 47.7%. This difference is statistically highly significant. Except for one case, the beneficial effect was always recorded in the place of administration (under the anode). Apart from local skin irritation in 2 patients and spot burns under the electrode in 2, no other side adverse effects were seen in the course of therapy, after its termination or at the checks made after some time interval (maximum 3 years).