Topical Application of Nitric Oxide Donor Isosorbide Dinitrate Appears to Improve Symptoms of Complex Regional Pain Syndrome
Posted January 17th, 2008 by Matt
Complex regional pain syndrome (CRPS) is a disorder that causes
chronic, often severe pain. The syndrome follows a seemingly minor soft tissue injury or fracture.
Up to now, little has been found to help relieve the symptoms patients experience with CRPS: change in tissue blood flow, skin temperature, edema (swelling from fluid), and sweating, among others. Although some analgesics may relieve some pain, some patients do end up having affected limbs amputated.
The authors of this study wanted to see if improving the blood flow to the affected limb would reduce damage that may result in the need for amputation. To do this, researchers recruited five women, average age 49.6 years, to be treated on the affected hand with nitric oxide donor isosorbide dinitrate ointment (ISDN), which would cause dilation (widening) of the blood vessels, allowing for improved blood flow. The ointment was applied four times a day for 10 weeks.
The researchers measured skin temperature, comparing the affected side with the non-affected side, and patients used a weekly diary using the Visual Analog Scale> to rate pain from one to 100, with 100 being the worst possible pain. The pain intensity was assessed with the McGill Pain Questionnaire. Hand and arm strength, and elbow extension were also measured.
At two weeks following the start of the study, the researchers found an increase of approximately 4 degrees Celsius in the affected hand. The muscle force in the elbow remained the same in four patients, but deteriorated in one. Three patients complained of headache during the first two weeks of treatment.
The authors concluded that, although reliability of the study is limited because of the small size (five patients), the treatment does appear to affect body temperature where applied and may prove to be a viable treatment for CRPS.
George Groeneweg, BS, et al. Vasodilative Effect of Isosorbide Dinitrate Ointment in Complex Regional Pain Syndrome Type 1. In Clinical Journal of Pain. January 2008. Vol. 1. No. 24. Pp. 89-92.