Intranasal Capsaicin Shows Promise for Pain Relief of Severe Headaches and Migraine
Treatment desensitizes trigeminal nerve
Positive results from a “real world” analysis of intranasal capsaicin (VR1, Inc.) as a treatment for severe headache and migraine pain were presented May 1 at the 66th American Academy of Neurology (AAN) annual meeting in Philadelphia, Pennsylvania.
Intranasal capsaicin has been shown to be effective in the treatment of migraines and cluster headaches and is thought to work by calcium-mediated desensitization of the trigeminal nerve and resultant depletion of calcitonin gene-related peptide (CGRP), the neurotransmitter responsible for migraine pain. Until the new analysis was conducted, intranasal capsaicin had not been evaluated in other types of severe headaches, and its effectiveness in these patients was not known.
Investigators evaluated 18 adult patients (28 to 65 years of age) with different severe headache diagnoses (i.e., cluster headache, post-traumatic headache, tension-type headache, and medication overuse/rebound headache) as well as migraine who were treated with intranasal capsaicin. All of the patients had moderate-to-severe functional disability as a result of the severity of their headaches and expressed dissatisfaction with their current treatment regimens, which included commonly used prescription and non-prescription headache medications, such as naproxen, sumatriptan, rizatriptan, verapamil, and butalbital.
The patients were asked to use intranasal capsaicin to treat their headaches without any additional medication. They were also asked to report on the effectiveness and tolerability of the medication and on whether they would continue to use the treatment for future headache episodes.
Of the 18 patients, 13 (72.2%) experienced complete pain relief, as reported on a five-point scale ranging from no relief (1+) to complete pain relief (5+). Most of the remaining patients also reported experiencing some pain relief (4+ [one patient); 3+ [two patients], and 2+ [one patient]), and one patient reported no pain relief (1+).
Eight patients (44.4%) experienced immediate pain relief (less than 1 minute after use); seven patients (38.9%) experienced the intermediate onset of pain relief (between 1 to 3 minutes after use); two patients (11.1%) had “delayed” relief (more than 3 minutes after use); and one patient (5.6%) had no response. The reported duration of relief ranged from 30 minutes to several hours.
All 18 patients reported experiencing the local adverse event of nasal stinging, which lasted between 2 and 10 minutes, and lacrimation. The 17 patients who achieved pain relief continued to use intranasal capsaicin for subsequent episodes and reported that the stinging would not dissuade them from using the medication.
Capsaicin is a constituent of oleoresin capsicum — an extract of the chili pepper plant Capsicum annuum. Extracts of the plant, including capsaicin, have been used for centuries as an analgesic. More recently, these extract have been studied in the treatment of severe nerve pain in conditions such as post-shingles pain and diabetic neuropathy. During the last two decades, clinical data have demonstrated that intranasal administration of capsicum annuum or its components, including capsaicin, can successfully treat pain associated with cluster headaches and migraine.
The intranasal administration of extracts of capsicum annuum is thought to work locally by desensitizing the trigeminal nerve, resulting in the reduction of CGRP molecules. CGRP is believed to cause the swelling and inflammation of blood vessels surrounding the brain that is associated with the pain of severe headaches and migraine. When administered locally in the nose, extracts of capsicum annuum cause a stinging sensation, indicating that therapeutic action on the sensory nerve has occurred.
Migraine ranks among the top 10 of the world’s most disabling medical conditions, with nearly 36 million people affected by the disorder in the U.S. alone. More than 90% of people with migraine are unable to work or to function normally during their attacks. Direct medical costs and indirect costs of migraine, including millions of missed work days and lost productivity, total approximately $29 billion a year in the U.S.
Source: PR Newswire; April 30, 2014.