Chronic pain is a complicated disorder that can be influenced as much by mood and personal experience as it can by persistent inflammation or unresolved pain. In some cases when pain is constantly relayed through the peripheral nerves to the central nervous system, a sort of imprint or pain memory is created, leading to chronic pain. Resolvins can dampen the nerve transmission that leads to chronic pain by acting both at the peripheral nerve and in the spine.

Although not all cases of chronic pain involve inflammation, the majority do. Therapy options for chronic pain are complicated because of the ongoing nature of the symptom.

While the causes of chronic pain are many and diverse, the pervasive effect it has on a patient’s life—including inability to work, anxiety, depression, and even post-traumatic stress disorder—is universal. Opiates such as morphine are considered among the best medications for relieving pain, but they carry a risk of tolerance and addiction, especially with long-term use. Many doctors thus prefer to prescribe anti-inflammatory drugs such as cyclooxygenase (COX) inhibitors. COX inhibitors, like aspirin or ibuprofen, however, can cause gastrointestinal bleeding and kidney damage when used at high doses, and selective COX-2 inhibitors such as Vioxx have been shown to increase the risk of cardiovascular disease. In addition, these drugs are most effective for mild and moderate pain; they have a “ceiling” beyond which taking more provides no more relief.

One difference between acute inflammation and the persistent inflammation that leads to chronic pain, is that in the latter, the inflammatory factors are never completely cleared from the system. Recent research has revealed that the clearing of these inflammatory factors is an active process rather than a passive one that simply occurs over time. This insight offers the possibility that we might be able to harness resolution factors that clear inflammation and use them to ameliorate the pain that accompanies chronic inflammation.

By Claudia Sommer and Frank Birklein. Read the full article here