Intravenous infusions in chronic pain management.

In the United States, millions of Americans are affected by chronic pain, which adds heavily to national rates of morbidity, mortality, and disability, with an ever-increasing prevalence. According to a 2011 report titled Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research by the Institute of Medicine of the National Academies, pain not only exacts its toll on people's lives but also on the economy with an estimated annual economic cost of at least $560 - 635 billion in health care costs and the cost of lost productivity attributed to chronic pain. Intravenous infusions of certain pharmacologic agents have been known to provide substantial pain relief in patients with various chronic painful conditions. Some of these infusions are better, and although not necessarily the first therapeutic choice, have been widely used and extensively studied. The others show promise, however are in need of further investigations. This article will focus on non-opiate intravenous infusions that have been utilized for chronic painful disorders such as fibromyalgia, neuropathic pain, phantom limb pain, post-herpetic neuralgia, complex regional pain syndromes (CRPS), diabetic neuropathy, and central pain related to stroke or spinal cord injuries. The management of patients with chronic pain conditions is challenging and continues to evolve as new treatment modalities are explored and tested. The following intravenous infusions used to treat the aforementioned chronic pain conditions will be reviewed: lidocaine, ketamine, phentolamine, dexmedetomidine, and bisphosphonates. This overview is intended to familiarize the practitioner with the variety of infusions for patients with chronic pain. It will not, however, be able to provide guidelines for their use due to the lack of sufficient evidence.