Abstract

Background: The use of botulinum toxin type A subcutaneously has been reported in the literature in the last decade. The mechanism of action for this use has not been fully elucidated, given the effect reported in relief of allodynia, paroxysmal pain and hyperalgesia. The report in the literature is with the use of onabotulintoxin A. Material and Method To analyze results in pain relief in 9 patients with intractable neuropathic pain treated with abobotulintoxin A injections, in the Pain Relief Unit of a public hospital in the metropolitan region of Chile, with an observational, retrospective and descriptive study. Clinical record analysis of 9 individuals with neuropathic pain considered refractory to combined pharmacological treatment for neuropathic pain at maximal doses, who had allodynia component and paroxysmal pain as a characteristic of neuropathic pain, and who received injection of subcutaneous or intradermal abobotulintoxin A in the area of persistent allodynia. Results 7 patients out of 9 had expected outcomes, allodynia relief of at least 50% after the first dose, and 80% relief of incidental paroxysmal pain and with relief of 80% allodynia after the second dose three months after the first. Of these, 5 were able to decrease the requirement of potent opioids. 2 patients out of 9 had no satisfactory results: 1 had no results, and 1 had a favorable outcome but with a short duration of effect. Conclusions Subcutaneous injection of abobotulintoxin A may be an effective therapeutic tool in patients with neuropathic pain characterized by allodynia and paroxysmal pain.