effect of minocycline on lumbar radicular pain: a prospective pilot study

Introduction: pain is an unpleasant sensory and emotional experience. evidence suggests a role for microglia in chronic pain and inhibition of microglia leads to decrease of chronic pain intensity in animal models. minocycline, a semisynthetic tetracycline derivative, is a selective inhibitor of microglia. several studies have shown pain intensity improvement by minocycline in animal model of pain, but a few studies showed effectiveness on chronic pain improvement in humans. this prospective, self-controlled clinical trial investigated whether minocycline is effective for chronic pain management. methods: twenty-two patients, between the ages of 20 and 80 years with radicular lumbar pain with a numerical rating scale >4, who were unresponsive to other medications and had pain duration of >6 weeks were included in the trial. results: pain intensity, neuropathic pain and life quality scores assessed before and after treatment. all scores showed significant improvement after 2 weeks of treatment: 56%, 74% and 14%, respectively. conclusion: findings of this study suggest minocycline can effectively improve patients’ pain scores and quality of life, even in those with long-term duration of chronic pain and warrants further study.